DYSTROPHIN GENE EXON DELETION USING ENGINEERED NUCLEASES

Abstract

The invention relates to the field of molecular biology and recombinant nucleic acid technology. In particular, the invention relates to a method of treating a patient with Duchenne Muscular Dystrophy comprising the removal of at least one exon from the dystrophin gene using engineered nucleases.

Claims

1. A method comprising contacting the DNA of a muscle cell of a mammalian subject with a first nuclease that cuts a first recognition sequence and a second nuclease that cuts a second recognition sequence; wherein said first recognition sequence is within an intron that is 5′ upstream of a first exon in a dystrophin gene of said muscle cell; wherein said second recognition sequence is within an intron that is 3′ downstream of said first exon in said dystrophin gene of said muscle cell; wherein said first recognition sequence and said second recognition sequence are selected to have complementary overhangs when cut by said first nuclease and said second nuclease; wherein said first exon and at least a second exon are removed from said dystrophin gene in said muscle cell; wherein said complementary overhangs of said first recognition sequence and said second recognition sequence are re-ligated to one another; and wherein a normal reading frame of said dystrophin gene is restored.

2. The method of claim 1, wherein said first exon is Exon 44.

3. The method of claim 1, wherein said first exon is Exon 45.

4. The method of claim 1, wherein said first exon is Exon 51.

5. The method of claim 2, wherein said first recognition sequence is SEQ ID NO: 19, and said second recognition sequence is SEQ ID NO: 42.

6. The method of claim 3, wherein: (a) said first recognition sequence is selected from SEQ ID NOs: 50, 51, 53, and 56, and wherein said second recognition sequence is SEQ ID NO: 73; (b) said first recognition sequence is selected from SEQ ID NOs: 54 and 60, and wherein said second recognition sequence is SEQ ID NO: 67; (c) said first recognition sequence is SEQ ID NO: 55, and wherein said second recognition sequence is SEQ ID NO: 66; or (d) said first recognition sequence is SEQ ID NO: 62, and wherein said second recognition sequence is SEQ ID NO: 74.

7. The method of claim 4, wherein: (a) said first recognition sequence is SEQ ID NO: 76, and wherein said second recognition sequence is SEQ ID NO: 134; (b) said first recognition sequence is selected from SEQ ID NOs: 78 and 83, and wherein said second recognition sequence is selected from SEQ ID NOs: 110, 111, and 117; (c) said first recognition sequence is selected from SEQ ID NOs: 79 and 82, and wherein said second recognition sequence is SEQ ID NO: 119; (d) said first recognition sequence is selected from SEQ ID NOs: 85 and 99, and wherein said second recognition sequence is selected from SEQ ID NOs: 120, 124, and 131; (e) said first recognition sequence is SEQ ID NO: 87, and wherein said second recognition sequence is SEQ ID NO: 126; (f) said first recognition sequence is selected from SEQ ID NOs: 88, 93, and 103, and wherein said second recognition sequence is SEQ ID NO: 114 (g) said first recognition sequence is selected from SEQ ID NOs: 89 and 100, and wherein said second recognition sequence is SEQ ID NO: 128 (h) said first recognition sequence is SEQ ID NO: 91, and wherein said second recognition sequence is selected from SEQ ID NOs: 108, 127, and 133; (i) said first recognition sequence is SEQ ID NO: 92, and wherein said second recognition sequence is selected from SEQ ID NOs: 116 and 129; (j) said first recognition sequence is SEQ ID NO: 96, and wherein said second recognition sequence is selected from SEQ ID NOs: 112, 123, and 130; (k) said first recognition sequence is SEQ ID NO: 97, and wherein said second recognition sequence is SEQ ID NO: 118; or (l) said first recognition sequence is SEQ ID NO: 105, and wherein said second recognition sequence is selected from SEQ ID NOs: 106 and 107.

8. The method of claim 5, wherein said first nuclease comprises the amino acid sequence of SEQ ID NO: 135 and said second nuclease comprises the amino acid sequence of SEQ ID NO: 136.

9. The method of claim 6, wherein said first nuclease comprises the amino acid sequence of SEQ ID NO: 137 and said second nuclease comprises the amino acid sequence of SEQ ID NO: 138.

10. The method of claim 1, wherein the genes encoding said first nuclease and said second nuclease are delivered to said muscle cell using a recombinant adeno-associated virus (AAV).

11. The method of claim 1, wherein the subject is a human.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0020] FIG. 1. Structure of the DMD gene. 79 exons are drawn to indicate reading frame. The essential Actin-binding and Dystroglycan-binding domains, which span approximately Exons 2-8 and 62-70, respectively, are indicated.

[0021] FIG. 2A-2E. Strategies for deleting exons from the DMD gene using different types of nucleases. FIG. 2A) Strategy for deleting an exon using a pair of CRISPRs. A pair of “guide RNAs” (“gRNAs”) are used which are complementary to a pair of recognition sites flanking the exon of interest. As drawn in this figure, the gRNAs can be complementary to recognition sequences that are distal to the conserved “GG” motif and the site of Cas9 DNA cleavage. In this orientation, the CRISPR recognition sequences are largely conserved following DNA cleavage, excision of the intervening fragment of genomic DNA, and re-joining of the chromosome ends. FIG. 2B) An alternative scheme for deleting an exon using a pair of CRISPRs in which the gRNAs are complementary to recognition sequences that are proximal to the exon. In this orientation, the CRISPR recognition sequences are largely deleted following DNA cleavage, excision of the intervening fragment of genomic DNA, and re-joining of the chromosome ends. It is contemplated in the invention could also comprise a hybrid of the schemes shown in FIG. 2A and FIG. 2B. FIG. 2C) Strategy for deleting an exon using a pair of compact TALENs (cTALENs). A pair of TAL effector DNA-binding domains (“TALEs”) are used which bind to a pair of recognition sites flanking the exon of interest. As drawn in this figure, the TALEs can bind to recognition sequences that are distal to the conserved “CNNNG” motif that is recognized and cut by the I-TevI cleavage domain (“TevI-CD”). In this orientation, the cTALEN recognition sequences are largely conserved following DNA cleavage, excision of the intervening fragment of genomic DNA, and re-joining of the chromosome ends. Also, the cTALENs in this figure are shown with the TALE and TevI-CD domains in an N- to C-orientation. It is also possible to generate cTALENs with these two domains in a C- to N-orientation. FIG. 2D) An alternative scheme for deleting an exon using a pair of cTALENS in which the TALE domains bind to recognition sequences that are proximal to the exon. In this orientation, the cTALEN recognition sequences are largely deleted following DNA cleavage, excision of the intervening fragment of genomic DNA, and re-joining of the chromosome ends. Also, the cTALENs in this figure are drawn with the TALE and TevI-CD domains in a C- to N-orientation. It is contemplated in the invention could also comprise a hybrid of the schemes shown in FIG. 2C and FIG. 2D. FIG. 2E) Strategy for deleting an exon from the DMD gene using a pair of single-chain meganucleases. The meganucleases are drawn as two-domain proteins (MGN-N: the N-terminal domain; and MGN-C: the C-terminal domain) joined by a linker. In the figure, the C-terminal domain is drawn as binding to the half of the recognition sequence that is closest to the exon. In some embodiments, however, the N-terminal domain can bind to this half of the recognition sequence. The central four basepairs of the recognition sequence are shown as “NNNN”. These four basepairs become single-strand 3′ “overhangs” following cleavage by the meganuclease. The subset of preferred four basepair sequences that comprise this region of the sequence are identified in WO/2010/009147. DNA cleavage by the pair of meganucleases generates a pair of four basepair 3′ overhangs at the chromosome ends. If these overhangs are complementary, they can anneal to one another and be directly re-ligated, resulting in the four basepair sequence being retained in the chromosome following exon excision. Because meganucleases cleave near the middle of the recognition sequence, half of each recognition sequence will frequently be retained in the chromosome following excision of the exon. The other half of each recognition sequence will removed from the genome with the exon.

[0022] FIG. 3A-3C. Excision of DMD Exon 44 using the DYS-1/2 and DYS-3/4 meganucleases. FIG. 3A) Sequence of DMD Exon 44 and flanking regions. The Exon sequence is underlined. Recognition sites for the DYS-1/2 and DYS-3/4 meganucleases are shaded in gray with the central four basepairs (which become the 3′ overhang following cleavage by the meganuclease) in bold. Annealing sites for a pair of PCR primers used for analysis are italicized. FIG. 3B) Agarose gel electrophoresis analysis of HEK-293 cells co-expressing DYS-1/2 and DYS-3/4. Genomic DNA was isolated from the cells and evaluated by PCR using the primers indicated in (FIG. 3A). PCR products were resolved on an agarose gel and it was found that HEK-293 cells co-expressing the two meganucleases yielded a pair of PCR bands whereas wild-type HEK-293 cells yielded only the larger band. FIG. 3C) sequences from three plasmids harboring the smaller PCR product from (FIG. 3B). The three sequences are shown aligned to the wild-type human sequence. The locations of the DYS-1/2 and DYS-3/4 recognition sequences are shaded in gray with the central four basepairs in bold.

[0023] FIG. 4A-4C. Excision of DMD Exon 45 using the DYS-5/6 and DYS-7/8 meganucleases. FIG. 4A) Sequence of DMD Exon 45 and flanking regions. The Exon sequence is underlined. Recognition sites for the DYS-5/6 and DYS-7/8 meganucleases are shaded in gray with the central four basepairs (which become the 3′ overhang following cleavage by the meganuclease) in bold. Annealing sites for a pair of PCR primers used for analysis are italicized. FIG. 4B) Agarose gel electrophoresis analysis of HEK-293 cells co-expressing DYS-5/6 and DYS-7/8. Genomic DNA was isolated from the cells and evaluated by PCR using the primers indicated in (FIG. 4A). PCR products were resolved on an agarose gel and it was found that HEK-293 cells co-expressing the two meganucleases yielded a pair of PCR bands whereas wild-type HEK-293 cells yielded only the larger band. FIG. 4C) sequences from 16 plasmids harboring the smaller PCR product from (FIG. 4B). The sequences are shown aligned to the wild-type human sequence. The locations of the DYS-5/6 and DYS-7/8 recognition sequences are shaded in gray with the central four basepairs in bold.

[0024] FIG. 5A-5C. Evaluation of the MDX-1/2 and MDX-13/14 meganucleases in a reporter assay in CHO cells. FIG. 5A) Schematic of the assay. For each of the two meganucleases, we produced a CHO cell line in which a reporter cassette was integrated stably into the genome of the cell. The reporter cassette comprised, in 5′ to 3′ order: an SV40 Early Promoter; the 5′ 2/3 of the GFP gene; the recognition site for either MDX-1/2 (SEQ ID NO: 149) or the recognition site for MDX-13/14 (SEQ ID NO: 150); the recognition site for the CHO-23/24 meganuclease (WO/2012/167192); and the 3′ 2/3 of the GFP gene. Cells stably transfected with this cassette did not express GFP in the absence of a DNA break-inducing agent. When a DNA break was induced at either of the meganuclease recognition sites, however, the duplicated regions of the GFP gene recombined with one another to produce a functional GFP gene. The percentage of GFP-expressing cells could then be determined by flow cytometry as an indirect measure of the frequency of genome cleavage by the meganucleases. FIG. 5B and FIG. 5C) The two CHO reporter lines were transfected with mRNA encoding the MDX-1/2 (A), MDX-13/14 (FIG. 5B), or CHO-23/34 (FIG. 5A and FIG. 5B) meganucleases. 1.5e6 CHO cells were transfected with 1e6 copies of mRNA per cell using a Lonza Nucleofector 2 and program U-024 according to the manufacturer's instructions. 48 hours post-transfection, the cells were evaluated by flow cytometry to determine the percentage of GFP-positive cells compared to an untransfected (Empty) negative control. The assay was performed in triplicate and standard deviations are shown. The MDX-1/2 and MDX-13/14 meganucleases were found to produce GFP+ cells in their respective cell lines at frequencies significantly exceeding both the negative (Empty) control and the CHO-23/24 positive control, indicating that the nucleases are able to efficiently recognize and cut their intended target sequences in a cell.

[0025] FIG. 6. Sequence alignments from 20 C2C12 mouse myoblast clones in which a portion of the DMD gene was deleted by co-transfection with the MDX-1/2 and MDX-13/14 meganucleases. The location of DMD Exon 23 is shown as are the locations and sequences of the MDX-1/2 and MDX-13/14 target sites. Each of the 20 sequences (SEQ ID NO: 153-172) was aligned to a reference wild-type DMD sequence and deletions relative to the reference are shown as hollow bars.

[0026] FIG. 7. Vector map of the pAAV-MDX plasmid. This “packaging” plasmid was used in conjunction with an Ad helper plasmid to produce AAV virus capable of simultaneously delivering the genes encoding the MDX-1/2 and MDX-13/14 meganucleases.

DETAILED DESCRIPTION OF THE INVENTION

1.1 References and Definitions

[0027] The patent and scientific literature referred to herein establishes knowledge that is available to those of skill in the art. The issued U.S. patents, allowed applications, published foreign applications, and references, including GenBank database sequences, that are cited herein are hereby incorporated by reference to the same extent as if each was specifically and individually indicated to be incorporated by reference.

[0028] As used herein, the term “meganuclease” refers to an endonuclease that is derived from I-CreI. The term meganuclease, as used herein, refers to an engineered variant of I-CreI that has been modified relative to natural I-CreI with respect to, for example, DNA-binding specificity, DNA cleavage activity, DNA-binding affinity, or dimerization properties. Methods for producing such modified variants of I-CreI are known in the art (e.g. WO 2007/047859). A meganuclease may bind to double-stranded DNA as a homodimer, as is the case for wild-type I-CreI, or it may bind to DNA as a heterodimer. A meganuclease may also be a “single-chain meganuclease” in which a pair of DNA-binding domains derived from I-Ciel are joined into a single polypeptide using a peptide linker.

[0029] As used herein, the term “single-chain meganuclease” refers to a polypeptide comprising a pair of meganuclease subunits joined by a linker. A single-chain meganuclease has the organization: N-terminal subunit—Linker—C-terminal subunit. The two meganuclease subunits, each of which is derived from I-CreI, will generally be non-identical in amino acid sequence and will recognize non-identical DNA sequences. Thus, single-chain meganucleases typically cleave pseudo-palindromic or non-palindromic recognition sequences. A single chain meganuclease may be referred to as a “single-chain heterodimer” or “single-chain heterodimeric meganuclease” although it is not, in fact, dimeric. For clarity, unless otherwise specified, the term “meganuclease” can refer to a dimeric or single-chain meganuclease.

[0030] As used herein, the term “Compact TALEN” refers to an endonuclease comprising a DNA-binding domain with 16-22 TAL domain repeats fused in any orientation to any portion of the I-TevI homing endonuclease.

[0031] As used herein, the term “CRISPR” refers to a caspase-based endonuclease comprising a caspase, such as Cas9, and a guide RNA that directs DNA cleavage of the caspase by hybridizing to a recognition site in the genomic DNA.

[0032] As used herein, with respect to a protein, the term “recombinant” means having an altered amino acid sequence as a result of the application of genetic engineering techniques to nucleic acids which encode the protein, and cells or organisms which express the protein. With respect to a nucleic acid, the term “recombinant” means having an altered nucleic acid sequence as a result of the application of genetic engineering techniques. Genetic engineering techniques include, but are not limited to, PCR and DNA cloning technologies; transfection, transformation and other gene transfer technologies; homologous recombination; site-directed mutagenesis; and gene fusion. In accordance with this definition, a protein having an amino acid sequence identical to a naturally-occurring protein, but produced by cloning and expression in a heterologous host, is not considered recombinant.

[0033] As used herein, the term “wild-type” refers to any naturally-occurring form of a meganuclease. The term “wild-type” is not intended to mean the most common allelic variant of the enzyme in nature but, rather, any allelic variant found in nature. Wild-type homing endonucleases are distinguished from recombinant or non-naturally-occurring meganucleases.

[0034] As used herein, the term “recognition sequence” refers to a DNA sequence that is bound and cleaved by an endonuclease. In the case of a meganuclease, a recognition sequence comprises a pair of inverted, 9 basepair “half sites” which are separated by four basepairs. In the case of a single-chain meganuclease, the N-terminal domain of the protein contacts a first half-site and the C-terminal domain of the protein contacts a second half-site. Cleavage by a meganuclease produces four basepair 3′ “overhangs”. “Overhangs”, or “sticky ends” are short, single-stranded DNA segments that can be produced by endonuclease cleavage of a double-stranded DNA sequence. In the case of meganucleases and single-chain meganucleases derived from I-CreI, the overhang comprises bases 10-13 of the 22 basepair recognition sequence. In the case of a Compact TALEN, the recognition sequence comprises a first CNNNGN sequence that is recognized by the I-TevI domain, followed by a non-specific spacer 4-16 basepairs in length, followed by a second sequence 16-22 bp in length that is recognized by the TAL-effector domain (this sequence typically has a 5′ T base). Cleavage by a Compact TALEN produces two basepair 3′ overhangs. In the case of a CRISPR, the recognition sequence is the sequence, typically 16-24 basepairs, to which the guide RNA binds to direct Cas9 cleavage. Cleavage by a CRISPR produced blunt ends.

[0035] As used herein, the term “target site” or “target sequence” refers to a region of the chromosomal DNA of a cell comprising a recognition sequence for a meganuclease.

[0036] As used herein, the term “homologous recombination” or “HR” refers to the natural, cellular process in which a double-stranded DNA-break is repaired using a homologous DNA sequence as the repair template (see, e.g. Cahill et al. (2006), Front. Biosci. 11:1958-1976). The homologous DNA sequence may be an endogenous chromosomal sequence or an exogenous nucleic acid that was delivered to the cell.

[0037] As used herein, the term “non-homologous end-joining” or “NHEJ” refers to the natural, cellular process in which a double-stranded DNA-break is repaired by the direct joining of two non-homologous DNA segments (see, e.g. Cahill et al. (2006), Front. Biosci. 11:1958-1976). DNA repair by non-homologous end-joining is error-prone and frequently results in the untemplated addition or deletion of DNA sequences at the site of repair.

[0038] As used herein, the term “re-ligation” refers to a process in which two DNA ends produced by a pair of double-strand DNA breaks are covalently attached to one another with the loss of the intervening DNA sequence but without the gain or loss of any additional DNA sequence. In the case of a pair of DNA breaks that are produced with single-strand overhangs, re-ligation can proceed via annealing of complementary overhangs followed by covalent attachment of 5′ and 3′ ends by a DNA ligase. Re-ligation is distinguished from NHEJ in that it does not result in the untemplated addition or removal of DNA from the site of repair.

[0039] As used herein, unless specifically indicated otherwise, the word “or” is used in the inclusive sense of “and/or” and not the exclusive sense of “either/or.”

2.1 Principle of Exon Deletion

[0040] The present invention is based, in part, on the hypothesis that certain deletions in the DMD gene that give rise to the Duchenne phenotype can be compensated for by deleting (an) additional exon(s) immediately up- or downstream of the mutation. The DMD-Leiden Database indicates that most of the mutations that cause Duchenne Muscular Dystrophy are deletions of one or more whole exons that cause a shift in reading frame. In many cases, the reading frame can be restored by eliminating the exon immediately before or after the mutation. As shown in Table 1, 29 different Duchenne-causing mutations, representing ˜65% of patients, can be compensated for by deleting a single exon adjacent to the mutation. For example, a patient with disease due to the deletion of DMD Exon 45, which occurs in approximately 7% of patients, can be treated with a therapeutic that deletes Exon 46. Notably, a therapeutic capable of deleting Exon 51 or Exon 45 could be used to treat 15% and 13% of patients, respectively.

TABLE-US-00001 TABLE 1 Exon(s) deleted Additional Frequency in DMD- in patient Exon to delete Leiden Database (%) 44, 44-47 43 5 35-43, 45, 45-54 44 8 18-44, 44, 46-47, 46-48, 45 13 46-49, 46-51, 46-53 45 46 7 51, 51-55 50 5 50, 45-50, 48-50, 49-50, 51 15 52, 52-63 51, 53, 53-55 52 3 45-52, 48-52, 49-52, 53 9 50-52, 52

2.2 Nucleases for Deleting Exons

[0041] It is known in the art that it is possible to use a site-specific nuclease to make a DNA break in the genome of a living cell and that such a DNA break can result in permanent modification of the genome via mutagenic NHEJ repair or via HR with a transgenic DNA sequence. The present invention, however, involves co-expression of a pair of nucleases in the same cell. Surprisingly, we found that a pair of nucleases targeted to DNA sites in close proximity to one another (less than 10,000 basepairs apart) can excise the intervening DNA fragment from the genome. Also surprisingly, we found that DNA excision using a pair of nucleases frequently proceeds via a mechanism involving the single-stranded DNA overhangs generated by the nucleases. In experiments involving a pair of meganucleases that generate complementary (i.e. identical) DNA overhangs, it was found that the overhang sequence was frequently conserved following fragment excision and repair of the resulting chromosome ends (see Examples 1 and 2). The mechanism of DNA repair, in this case, appears to direct re-ligation of the broken ends, which has not been observed in mammalian cells. Such precise deletion and re-ligation was not observed when using a pair of meganucleases that generated non-identical overhangs (see Example 3). Thus, in a preferred embodiment, the pair of nucleases used for DMD exon excision are selected to generate complementary overhangs.

[0042] To excise an exon efficiently, the pair of nuclease cut sites need to be relatively close together. In general, the closer the two sites are to one another, the more efficient the process will be. Thus, the preferred embodiment of the invention uses a pair of nucleases that cut sequences that are less than 10,000 basepairs or, more preferably, 5,000 basepairs or, still more preferably, less than 2,500 basepairs, or, most preferably, less than 1,500 basepairs apart.

[0043] As shown in FIG. 2, a variety of different types of nuclease are useful for practicing the invention. FIGS. 2A and 2B show examples of how the invention can be practiced using a pair of CRISPR nucleases. In this case, the invention can be practiced by delivering three genes to the cell: one gene encoding the Cas9 protein and one gene encoding each of the two guide RNAs. CRISPRs cleave DNA to leave blunt ends which are not generally re-ligated cleanly such that the final product will generally have additiona insertion and/or deletion (“indel”) mutations in the sequence. In an alternative embodiment, a “CRISPR Nickase” may be used, as reported in Ran, et al. (2013) Cell. 154:1380-9. To practice this embodiment, it is necessary to express four guide RNAs in the cell, two of which are complementary to the sequence upstream of the exon and two of which are complementary to the sequence downstream of the exon. In this embodiment, the two pairs of guide RNAs hybridize with complementary strands in the target region and each member of the pair produces a single strand DNA nick on one of the strands. The result is a pair of nicks (equivalent to a double-strand break) that can be off-set from one another to yield a single-strand overhang that is advantageous for practicing the invention. Methods for making CRISPRs and CRISPR Nickases that recognize pre-determined DNA sites are known in the art, for example Ran, et al. (2013) Nat Protoc. 8:2281-308.

[0044] In alternative embodiments, as diagrammed in FIGS. 2C and 2D, the nuclease pair can be Compact TALENs. A compact TALEN comprises a TAL-effector DNA-binding domain (TALE) fused at its N- or C-terminus to the cleavage domain from I-TevI, comprising at least residues 1-96 and preferably residues 1-182 of I-TevI. The I-TevI cleavage domain recognizes and cuts DNA sequences of the form 5′-CNbNNtG-3′, where “b” represents the site of cleavage of the bottom strand and “t” represents the site of cleavage of the top strand and where“N” is any of the four bases. A Compact TALEN, thus, cleaves to produce two basepair 3′ overhangs. In a preferred embodiment, the Compact TALEN pair used for exon excision is selected to have complementary overhangs that can directly re-ligate. Methods for making TALE domains that bind to pre-determined DNA sites are known in the art, for example Reyon et al. (2012) Nat Biotechnol. 30:460-5.

[0045] In the preferred embodiment, as diagrammed in FIG. 2E, the nucleases used to practice the invention are a pair of Single-Chain Meganucleases. A Single-Chain Meganuclease comprises an N-terminal domain and a C-terminal domain joined by a linker peptide. Each of the two domains recognizes half of the Recognition Sequence and the site of DNA cleavage is at the middle of the Recognition Sequence near the interface of the two subunits. DNA strand breaks are offset by four basepairs such that DNA cleavage by a meganuclease generates a pair of four basepair, 3′ single-strand overhangs. In a preferred embodiment, single-chain meganucleases are selected which cut Recognition Sequences with complementary overhangs, as in Examples 1 and 2. Example recognition sequences for DMD Exons 44, 45, and 51 are listed in Tables 2-7. To excise Exon 44, for example, a first meganuclease can be selected which cuts a Recognition Sequence from Table 2, which lists Recognition Sequences upstream of Exon 44. A second meganuclease can then be selected which cuts a Recognition sequences from Table 3, which lists Recognition Sequences downstream of Exon 44. Co-expression of the two meganucleases in the same cell will thus excise Exon 44. Preferably, meganucleases are selected which cut DNA to leave complementary single strand overhangs. For example, SEQ ID NO: 19, if cut by a meganuclease, leaves the overhang sequence: 5′-GTAC-3′. Likewise, SEQ ID NO: 42 if cut by a meganuclease, leaves the overhang sequence: 5′-GTAC-3′. Thus, co-expressing a first meganuclease which cleaves SEQ ID NO: 19 with a second meganuclease which cleaves SEQ ID NO:42 will excise DMD Exon 44 from the genome of a human cell such that complementary overhangs are produced which can be repaired via direct re-ligation.

TABLE-US-00002 TABLE 2  Example Meganuclease Recognition Sequences Upstream of DMD Exon 44 Recognition Sequence SEQ ID NO: Overhang TTCTCTGTGGTGAGAAAATTTA 2 GTGA TTCACTATTTTGAAATATACAG 3 TTGA TATTTTGAAATATACAGCACAA 4 ATAT TAACTTTGTTCATATTACTATG 5 TCAT ACTTTGTTCATATTACTATGCA 6 ATAT CATATTACTATGCAATAGAACA 7 ATGC CACTAGAACTTATTACTCCTTT 8 TTAT TTTCAGTTGATGAACAGGCAGT 9 ATGA AGTTTTGGATCAAGAATAATAT 10 TCAA AAAAATATTTTGAAAGGGAATA 11 TTGA CCAAATAATTTATTACAATGTT 12 TTAT ATCTTTCTTTTAATCAATAAAT 13 TTAA TTTTAATCAATAAATATATTCA 14 ATAA ACCTTCCATTTAAAATCAGCTT 15 TTAA TCAGCTTTTATATTGAGTATTT 16 ATAT GCTTTTATATTGAGTATTTTTT 17 TTGA TAAAATGTTGTGTGTACATGCT 18 GTGT ATGTTGTGTGTACATGCTAGGT 19 GTAC GCTAGGTGTGTATATTAATTTT 20 GTAT ATTTGTTACTTGAAACTAAACT 21 TTGA CTAAACTCTGCAAATGCAGGAA 22 GCAA GTGATATCTTTGTCAGTATAAC 23 TTGT AAAAAATATACGCTATATCTCT 24 ACGC ATCTGTTTTACATAATCCATCT 25 ACAT CTGTTTTACATAATCCATCTAT 26 ATAA CTATTTTTCTTGATCCATATGC 27 TTGA CATATGCTTTTACCTGCAGGCG 28 TTAC

TABLE-US-00003 TABLE 3  Example Meganuclease Recognition Sequences Downstream of DMD Exon 44 Recognition Sequence SEQ ID NO: Overhang AAATTACTTTTGACTGTTGTTG 29 TTGA TGACTGTTGTTGTCATCATTAT 30 TTGT TTGTTGTCATCATTATATTACT 31 TCAT TTGTCATCATTATATTACTAGA 32 TEAT ATCATTATATTACTAGAAAGAA 33 TTAC AAAATTATCATAATGATAATAT 34 ATAA ATGGACTTTTTGTGTCAGGATG 35 TTGT GGACTTTTTGTGTCAGGATGAG 36 GTGT GGAGCTGGTTTATCTGATAAAC 37 TEAT ATTGAATCTGTGACAGAGGGAA 38 GTGA AGGGAAGCATCGTAACAGCAAG 39 TCGT GGGCAGTGTGTATTTCGGCTTT 40 GTAT TATATTCTATTGACAAAATGCC 41 TTGA TAATTGTTGGTACTTATTGACA 42 GTAC TGTTGGTACTTATTGACATTTT 43 TEAT TTTTATGGTTTATGTTAATAGG 44 TTAT

TABLE-US-00004 TABLE 4  Example Meganuclease Recognition Sequences Upstream of DMD Exon 45 Recognition Sequence SEQ ID NO: Overhang AGTTTTTTTTTAATACTGTGAC 45 TTAA TTTAATACTGTGACTAACCTAT 46 GTGA TTTCACCTCTCGTATCCACGAT 47 TCGT TCACCTCTCGTATCCACGATCA 48 GTAT CTCGTATCCACGATCACTAAGA 49 ACGA CCAAATACTTTGTTCATGTTTA 50 TTGT GGAACATCCTTGTGGGGACAAG 51 TTGT AATTTGCTCTTGAAAAGGTTTC 52 TTGA CTAATTGATTTGTAGGACATTA 53 TTGT TTCCCTGACACATAAAAGGTGT 54 ACAT CCCTGACACATAAAAGGTGTCT 55 ATAA CTTTCTGTCTTGTATCCTTTGG 56 TTGT ATCCTTTGGATATGGGCATGTC 57 ATAT TGGATATGGGCATGTCAGTTTC 58 GCAT GATATGGGCATGTCAGTTTCAT 59 ATGT GAAATTTTCACATGGAGCTTTT 60 ACAT TTTCTTTCTTTGCCAGTACAAC 61 TTGC TCTTTGCCAGTACAACTGCATG 62 GTAC TTTGGTATCTTACAGGAACTCC 63 TTAC

TABLE-US-00005 TABLE 5  Example Meganuclease Recognition Sequences Downstream of DMD Exon 45 Recognition Sequence SEQ ID NO: Overhang AAGAATATTTCATGAGAGATTA 64 TCAT GAATATTTCATGAGAGATTATA 65 ATGA TGAGAGATTATAAGCAGGGTGA 66 ATAA AAGGCACTAACATTAAAGAACC 67 ACAT TCAACAGCAGTAAAGAAATTTT 68 GTAA TTCTTTTTTTCATATACTAAAA 69 TCAT CTAAAATATATACTTGTGGCTA 70 ATAC TGAATATCTTCAATATATTTTA 71 TCAA CAATTATAAATGATTGTTTTGT 72 ATGA ATGATTGTTTTGTAGGAAAGAC 73 TTGT TCATATTTTGTACAAAATAAAC 74 GTAC

TABLE-US-00006 TABLE 6  Example Meganuclease Recognition Sequences Upstream of DMD Exon 51 Recognition Sequence SEQ ID NO: Overhang ATACGTGTATTGCTTGTACTAC 75 TTGC GTATTGCTTGTACTACTCACTG 76 GTAC ACTGAATCTACACAACTGCCCT 77 ACAC TGAATCTACACAACTGCCCTTA 78 ACAA CAACTGCCCTTATGACATTTAC 79 TTAT GGTAAATACATGAAAAATGCTT 80 ATGA TTGCCTTGCTTACTGCTTATTG 81 TTAC GCTTACTGCTTATTGCTAGTAC 82 TTAT TAGTACTGAACAAATGTTAGAA 83 ACAA ACTGAACAAATGTTAGAACTGA 84 ATGT AAGATTTATTTAATGACTTTGA 85 TTAA CAGTATTTCATGTCTAAATAGA 86 ATGT GGTTTTTCTTCACTGCTGGCCA 87 TCAC CAATCTGAAATAAAAAGAAAAA 88 ATAA CTGCTCCCAGTATAAAATACAG 89 GTAT AAGAACGTTTCATTGGCTTTGA 90 TCAT ACTTCCTATTCAAGGGAATTTT 91 TCAA TGTTTTTTCTTGAATAAAAAAA 92 TTGA TTTTCTTGAATAAAAAAAAAAT 93 ATAA TTGTTTTCTTTACCACTTCCAC 94 TTAC ACAATGTATATGATTGTTACTG 95 ATGA TGTATATGATTGTTACTGAGAA 96 TTGT CTTGTCCAGGCATGAGAATGAG 97 GCAT TGTCCAGGCATGAGAATGAGCA 98 ATGA AATCGTTTTTTAAAAAATTGTT 99 TTAA TTCTACCATGTATTGCTAAACA 100 GTAT TACCATGTATTGCTAAACAAAG 101 TTGC TATAATGTCATGAATAAGAGTT 102 ATGA ATGTCATGAATAAGAGTTTGGC 103 ATAA TTTTCCTTTTTGCAAAAACCCA 104 TTGC TTCCTTTTTGCAAAAACCCAAA 105 GCAA

TABLE-US-00007 TABLE 7  Example Meganuclease Recognition Sequences Downstream of DMD Exon 51 Recognition Sequence SEQ ID NO: Overhang AGTTCTTAGGCAACTGTTTCTC 106 GCAA TCTCTCTCAGCAAACACATTAC 107 GCAA TAAGTATAATCAAGGATATAAA 108 TCAA AGTAGCCATACATTAAAAAGGA 109 ACAT AGGAAATATACAAAAAAAAAAA 110 ACAA AGAAACCTTACAAGAATAGTTG 111 ACAA CAAGAATAGTTGTCTCAGTTAA 112 TTGT ATCTATTTTATACCAAATAAGT 113 ATAC TTATACCAAATAAGTCACTCAA 114 ATAA TTTGTTTTGGCACTACGCAGCC 115 GCAC TAAGGATAATTGAAAGAGAGCT 116 TTGA AGAAAAGTAACAAAACATAAGA 117 ACAA TTAAAGTTGGCATTTATGCAAT 118 GCAT AGTTGGCATTTATGCAATGCCA 119 TTAT AACATGTTTTTAATACAAATAG 120 TTAA TACATTGATGTAAATATGGTTT 121 GTAA ATATCTTTTATATTTGTGAATG 122 ATAT CTTTTATATTTGTGAATGATTA 123 TTGT TGTGAATGATTAAGAAAAATAA 124 TTAA AATTGTTATACATTAAAGTTTT 125 ACAT AAAGTTTTTTCACTTGTAACAG 126 TCAC TAACAGCTTTCAAGCCTTTCTA 127 TCAA GGTATTTAGGTATTAAAGTACT 128 GTAT TACTACCTTTTGAAAAAACAAG 129 TTGA GGAATTTCTTTGTAAAATAAAC 130 TTGT AACCTGCATTTAAAGGCCTTGA 131 TTAA TGAGCTTGAATACAGAAGACCT 132 ATAC TGATTGTGGTCAAGCCATCTCT 133 TCAA CTATTCTGAGTACAGAGCATAC 134 GTAC

2.3 Methods for Delivering and Expressing Nucleases

[0046] Treating Duchenne Muscular Dystrophy using the invention requires that a pair of nucleases be expressed in a muscle cell. The nucleases can be delivered as purified protein or as RNA or DNA encoding the nucleases. In one embodiment, the nuclease proteins or mRNA or vector encoding the nucleases are supplied to muscle cells via intramuscular injection (Maltzahn, et al. (2012) Proc Natl Acad Sci USA. 109:20614-9) or hydrodynamic injection (Taniyama et al. (2012) Curr Top Med Chem. 12:1630-7; Hegge, et al. (2010) Hum Gene Ther. 21:829-42). To facilitate cellular uptake, the proteins or nucleic acid(s) can be coupled to a cell penetrating peptide to facilitate uptake by muscle cells. Examples of cell pentrating peptides known in the art include poly-arginine (Jearawiriyapaisarn, et al. (2008) Mol Ther. 16:1624-9), TAT peptide from the HIV virus (Hudecz et al. (2005), Med. Res. Rev. 25: 679-736), MPG (Simeoni, et al. (2003) Nucleic Acids Res. 31:2717-2724), Pep-1 (Deshayes et al. (2004) Biochemistry 43: 7698-7706, and HSV-1 VP-22 (Deshayes et al. (2005) Cell Mol Life Sci. 62:1839-49. Alternatively, cell penetration can be facilitated by liposome encapsulation (see, e.g., Lipofectamine™, Life Technologies Corp., Carlsbad, Calif.). The liposome formulation can be used to facilitate lipid bilayer fusion with a target cell, thereby allowing the contents of the liposome or proteins associated with its surface to be brought into the cell.

[0047] In some embodiments, the genes encoding a pair of nucleases are delivered using a viral vector. Such vectors are known in the art and include lentiviral vectors, adenoviral vectors, and adeno-associated virus (AAV) vectors (reviewed in Vannucci, et al. (2013 New Microbiol. 36:1-22). In some embodiments, the viral vectors are injected directly into muscle tissue. In alternative embodiments, the viral vectors are delivered systemically. Example 3 describes a preferred embodiment in which the muscle is injected with a recombinant AAV virus encoding a pair of single-chain meganucleases. It is known in the art that different AAV vectors tend to localize to different tissues. Muscle-tropic AAV serotypes include AAV1, AAV9, and AAV2.5 (Bowles, et al. (2012) Mol Ther. 20:443-55). Thus, these serotypes are preferred for the delivery of nucleases to muscle tissue.

[0048] If the nuclease genes are delivered in DNA form (e.g. plasmid) and/or via a viral vector (e.g. AAV) they must be operably linked to a promoter. In some embodiments, this can be a viral promoter such as endogenous promoters from the viral vector (e.g. the LTR of a lentiviral vector) or the well-known cytomegalovirus- or SV40 virus-early promoters. In a preferred embodiment, the nuclease genes are operably linked to a promoter that drives gene expression preferentially in muscle cells. Examples of muscle-specific promoters include C5-12 (Liu, et al. (2004) Hum Gene Ther. 15:783-92), the muscle-specific creatine kinase (MCK) promoter (Yuasa, et al. (2002) Gene Ther. 9:1576-88), or the smooth muscle 22 (SM22) promoter (Haase, et al. (2013) BMC Biotechnol. 13:49-54). In some embodiments, the nuclease genes are under the control of two separate promoters. In alternative embodiments, the genes are under the control of a single promoter and are separated by an internal-ribosome entry site (IRES) or a 2A peptide sequence (Szymczak and Vignali (2005) Expert Opin Biol Ther. 5:627-38).

[0049] It is envisioned that a single treatment will permanently delete exons from a percentage of patient cells. In preferred embodiments, these cells will be myoblasts or other muscle precursor cells that are capable of replicating and giving rise to whole muscle fibers that express functional (or semi-functional) dystrophin. If the frequency of exon deletion is low, however, it may be necessary to perform multiple treatments on each patient such as multiple rounds of intramuscular injections.

EXAMPLES

[0050] This invention is further illustrated by the following examples, which should not be construed as limiting. Those skilled in the art will recognize, or be able to ascertain, using no more than routine experimentation, numerous equivalents to the specific substances and procedures described herein. Such equivalents are intended to be encompassed in the scope of the claims that follow the examples below.

Example 1

Deletion of DMD Exon 44 Using a Pair of Engineered, Single-Chain Meganucleases

[0051] 1. Meganucleases that Recognize SEQ ID NO: 19 and SEQ ID NO: 42

[0052] An engineered meganuclease (SEQ ID NO: 135) was produced which recognizes and cleaves SEQ ID NO: 19. This meganuclease is called “DYS-1/2”. A second engineered meganuclease (SEQ ID NO: 136) was produced which recognizes and cleaves SEQ ID NO: 42. This meganuclease is called “DYS-3/4” (FIG. 3A). Each meganuclease comprises an N-terminal nuclease-localization signal derived from SV40, a first meganuclease subunit, a linker sequence, and a second meganuclease subunit.

2. Deletion of DMD Exon 44 in HEK-293 Cells

[0053] Human embryonic kidney (HEK-293) cells were co-transfected with mRNA encoding DYS-1/2 and DYS-3/4. mRNA was prepared by first producing a PCR template for an in vitro transcription reaction (SEQ ID NO: 139 and SEQ ID NO: 140. Each PCR product included a T7 promoter and 609 bp of vector sequence downstream of the meganuclease gene. The PCR product was gel purified to ensure a single template. Capped (m7G) RNA was generated using the RiboMAX T7 kit (Promega) according to the manufacturer's instructions and. Ribo m7G cap analog (Promega) was included in the reaction and 0.5 ug of the purified meganuclease PCR product served as the DNA template. Capped RNA was purified using the SV Total RNA Isolation System (Promega) according to the manufacturer's instructions.

[0054] 1.5×10.sup.6 HEK-293 cells were nucleofected with 1.5×10.sup.12 copies of DYS-1/2 mRNA and 1.5×10.sup.12 copies of DYS-3/4 mRNA (2×10.sup.6 copies/cell) using an Amaxa Nucleofector II device (Lonza) according to the manufacturer's instructions. 48 hours post-transfection, genomic DNA was isolated from the cells using a FlexiGene kit (Qiagen) according to the manufacturer's instructions. The genomic DNA was then subjected to PCR using primers flanking the DYS-1/2 and DYS-3/4 cut sites (SEQ ID NO: 141 and SEQ ID NO:142). When PCR products were resolved by agarose gel electrophoresis, it was apparent that cells co-expressing DYS-1/2 and DYS-3/4 yielded two PCR products with apparent lengths of 1079 basepairs and 233 basepairs whereas genomic DNA from untransfected HEK-293 cells yielded only the larger product (FIG. 3B). The larger product is consistent with the expected size of a PCR fragment from cells with intact DMD Exon 44. The smaller product is consistent with the expected size of a PCR fragment from cells in which Exon 44 has been excised from the DMD gene.

[0055] The smaller PCR product was isolated from the gel and cloned into a bacterial plasmid (pUC-19) for sequence analysis. Three plasmid clones were sequenced, all of which were found to have Exon 44 deleted (FIG. 3C). Surprisingly, two of the three plasmids carried PCR products from cells in which the deletion consisted precisely of the region intervening the expected DYS-1/2 and DYS-3/4-induced DNA breaks. It appears that the two meganucleases cleaved their intended recognition sites, leaving compatible 5′-GTAC-3′ overhangs, the intervening fragment comprising Exon 44 was lost, and the two chromosome ends were then re-ligated. The third plasmid clone carried a PCR product from a cell in which the region intervening the two cleavage sites was excised along with 10 additional bases.

3. Conclusions

[0056] We have demonstrated that it is possible to use a pair of engineered single-chain meganucleases to excise a fragment from the human genome in a cultured cell line. The DNA removal and repair process appears to have proceeded via a mechanism that involves the 3′ overhangs produced by the nucleases, suggesting that the process is more efficient when the overhangs are complementary and able to anneal to one another.

Example 2

Deletion of DMD Exon 45 Using a Pair of Engineered, Single-Chain Meganucleases

[0057] 1. Meganucleases that Recognize SEQ ID NO: 62 and SEQ ID NO: 74

[0058] An engineered meganuclease (SEQ ID NO: 137) was produced which recognizes and cleaves SEQ ID NO: 62. This meganuclease is called “DYS-5/6”. A second engineered meganuclease (SEQ ID NO: 138) was produced which recognizes and cleaves SEQ ID NO: 74. This meganuclease is called “DYS-7/8” (FIG. 4A). Each meganuclease comprises an N-terminal nuclease-localization signal derived from SV40, a first meganuclease subunit, a linker sequence, and a second meganuclease subunit.

2. Deletion of DMD Exon 45 in HEK-293 Cells

[0059] Human embryonic kidney (HEK-293) cells were co-transfected with mRNA encoding DYS-5/6 and DYS-7/8. mRNA was prepared by first producing a PCR template for an in vitro transcription reaction (SEQ ID NO: 143(20) and SEQ ID NO: 144(21). Each PCR product included a T7 promoter and 609 bp of vector sequence downstream of the meganuclease gene. The PCR product was gel purified to ensure a single template. Capped (m7G) RNA was generated using the RiboMAX T7 kit (Promega) according to the manufacturer's instructions and. Ribo m7G cap analog (Promega) was included in the reaction and 0.5 ug of the purified meganuclease PCR product served as the DNA template. Capped RNA was purified using the SV Total RNA Isolation System (Promega) according to the manufacturer's instructions.

[0060] 1.5×10.sup.6 HEK-293 cells were nucleofected with 1.5×10.sup.12 copies of DYS-5/6 mRNA and 1.5×10.sup.12 copies of DYS-7/8 mRNA (2×10.sup.6 copies/cell) using an Amaxa Nucleofector II device (Lonza) according to the manufacturer's instructions. 48 hours post-transfection, genomic DNA was isolated from the cells using a FlexiGene kit (Qiagen) according to the manufacturer's instructions. The genomic DNA was then subjected to PCR using primers flanking the DYS-5/6 and DYS-7/8 cut sites (SEQ ID NO: 145 and SEQ ID NO:146). When PCR products were resolved by agarose gel electrophoresis, it was apparent that cells co-expressing DYS-5/6 and DYS-7/8 yielded two PCR products with apparent lengths of 1384 basepairs and 161 basepairs whereas genomic DNA from untransfected HEK-293 cells yielded only the larger product (FIG. 4B). The larger product is consistent with the expected size of a PCR fragment from cells with intact DMD Exon 45. The smaller product is consistent with the expected size of a PCR fragment from cells in which Exon 45 has been excised from the DMD gene.

[0061] The smaller PCR product was isolated from the gel and cloned into a bacterial plasmid (pUC-19) for sequence analysis. 16 plasmid clones were sequenced, all of which were found to have Exon 45 deleted (FIG. 4C). Surprisingly, 14 of the 16 plasmids carried PCR products from cells in which the deletion consisted precisely of the region intervening the expected DYS-5/6 and DYS-7/8-induced DNA breaks. It appears that the two meganucleases cleaved their intended recognition sites, leaving compatible 5′-GTAC-3′ overhangs, the intervening fragment comprising Exon 45 was lost, and the two chromosome ends were then re-ligated. The two remaining plasmid clones carried PCR product from cells in which the region intervening the two cleavage sites was excised along with 36 additional bases.

3. Conclusions

[0062] We have demonstrated that it is possible to use a pair of engineered single-chain meganucleases to excise a fragment from the human genome in a cultured cell line. The DNA removal and repair process appears to have proceeded via a mechanism that involves the 3′ overhangs produced by the nucleases, suggesting that the process is more efficient when the overhangs are complementary and able to anneal to one another.

Example 3

Deletion of DMD Exon 23 in a Mouse Using AAV-Delivered Meganucleases

1. Development of Nucleases to Delete Mouse DMD Exon 23

[0063] The standard mouse model of DMD is the mdx mouse, which has a point mutation in Exon 23 that introduces a premature stop codon (Sicinski et al. (1989) Science. 244:1578-80). In the mouse, DMD Exon 23 is 213 basepairs, equivalent to 71 amino acids. Thus, we reasoned that it should be possible to delete Exon 23 in its entirety and thereby remove the stop codon while maintaining the reading frame of the DMD gene. To this end, we developed a pair of single-chain meganucleases called “MDX-1/2” (SEQ ID NO: 147) and “MDX-13/14” (SEQ ID NO: 148). The former recognizes a DNA sequence upstream of mouse DMD Exon 23 (SEQ ID NO: 149) while the latter recognizes a DNA sequence downstream of mouse DMD Exon 23 (SEQ ID NO: 150). The nucleases were tested, initially, using a reporter assay called “iGFFP” in CHO cells as shown in FIG. 5. Both nucleases were found to efficiently cut their intended DNA sites using this assay.

2. Deletion of Mouse DMD Exon 23 in Mouse Myoblast Cells

[0064] A mouse myoblast cell line (C2C12) was co-transfected with in vitro transcribed mRNA encoding the MDX-1/2 and MDX-13/14 nucleases. mRNA was produced using the RiboMAX T7 kit from Promega. 1e6 C2C12 cells were Nucleofected with a total of 2e6 copies/cell of mRNA encoding each MDX enzyme pairs (1e6 copies of each mRNA) using an Amaxa 2b device and the B-032 program. After 96 hours, cells were cloned by limiting dilution in 96-well plates. After approximately 2 weeks growth, cells were harvested and genomic DNA was isolated using a FlexiGene kit from Qiagen. A PCR product was then generated for each clone using a forward primer in DMD Intron 22 (SEQ ID NO: 151) and a reverse primer in Intron 23 (SEQ ID NO: 152). 60 of the PCR products were then cloned and sequenced. 20 of the sequences had deletions consistent with meganuclease-induced cleavage of the DMD gene followed by mutagenic DNA repair (FIG. 6, SEQ ID NO:153-172). 11 of the sequences were missing at least a portion of the MDX-1/2 and MDX-13/14 recognition sites, as well as Exon 23 (SEQ ID NO:153-163). These sequences were likely derived from cells in which both nucleases cut their intended sites and the intervening sequence was deleted. 4 of the sequences were missing Exon 23 but had an intact MDX-1/2 recognition sequence (SEQ ID NO:164-167). These appear to be due to DNA cleavage by MDX-13/14 alone followed by the deletion of a large amount of sequence. Five of the sequences had an intact MDX-1/2 recognition site and all or a portion of Exon 23 but were missing all or a portion of the MDX-13/14 recognition site (SEQ ID NO:168-172). These sequences appear to be due to DNA cleavage by MDX-13/14 alone followed by the deletion of a smaller amount of sequence insufficient to eliminate all of Exon 23. In stark contrast to the experiments in Examples 1 and 2, we did not obtain a consistent DNA sequence following the deletion of DMD Exon 23 in the mouse cells. This is likely because the two MDX meganucleases do not generate DNA breaks with compatible 3′ overhangs. MDX-1/2 generates an overhang with the sequence 5′-GTGA-3′ and MDX-13/14 generates an overhang with the sequence 5′-ACAC-3′. Thus, we conclude that the consistent sequence results obtained in Examples 1 and 2 are due to the compatibility of the 3′ overhangs generated by the pair of meganucleases.

3. Generation of Recombinant AAV Vectors for Delivery of a Pair of Engineered Nucleases.

[0065] To produce AAV vectors for simultaneous delivery of MDX-1/2 and MDX-13/14 genes, we first produced a “packaging” plasmid called “pAAV-MDX” (FIG. 7, SEQ ID NO. 173) comprising a pair of inverted terminal repeat (ITR) sequences from AAV2, as well as the gene coding sequences for the MDX-1/2 and MDX-13/14 meganucleases, each under the control of a CMV Early promoter. This vector was used to produce recombinant AAV2 virus by co-transfection of HEK-293 cells with an Ad helper plasmid according to the method of Xiao, et al (Xiao, et al. (1998) J. Virology 72:2224-2232). Virus was then isolated by cesium-chloride gradient centrifugation as described by Grieger and Samulski (Grieger and Samulski (2012) Methods Enzymol. 507:229-254). To confirm that the resulting virus particles were infectious and capable of expressing both engineered meganucleases, they were added to cultured iGFFP CHO cells carrying reporter cassettes for either MDX-1/2 or MDX-13/14 (see FIG. 5A). The addition of recombinant virus particles to the CHO line carrying a reporter cassette for MDX-1/2 resulted in GFP gene expression in 7.1% of the cells. The addition of virus to the CHO line carrying a reporter for MDX-13/14 resulted in GFP gene expression in 10.2% of cells. Thus, we conclude that the virus was able to transduce CHO cells and that transduced cells expressed both nucleases.

4. Deletion of DMD Exon 23 in Mouse Muscle Following AAV Delivery of a Pair of Meganuclease Genes.

[0066] Recombinant AAV1 virus particles carrying the MDX-1/2 and MDX-13/14 genes were produced as described above. Three hindlimb TA muscles from a pair of mdx mice were injected with virus as described in Xiao, et al (Xiao, et al. (1998) J. Virology 72:2224-2232). One muscle from one mouse was not injected as a negative control. Muscles from the two mice were harvested at 4 days or 7 days post-injection and genomic DNA was isolated from the muscle tissue. The genomic region surrounding DMD Exon 23 was amplified by PCR using a first primer pair (SEQ ID NO:151 and SEQ ID NO: 152). This reaction was then used to template a second PCR reaction using a “nested” primer pair (SEQ ID NO:174 and SEQ ID NO: 175) to eliminate non-specific PCR products. PCR products were then visualized on an agarose gel and it was found that genomic DNA from the three AAV1 injected muscles, but not the un-injected control muscle, yielded smaller PCR products that were consistent in size with the product expected following deletion of DMD Exon 23 by the MDX-1/2 and MDX-13/14 meganucleases. The smaller PCR products were then cloned and sequenced. Three unique sequences were obtained, each of which comprised a portion of the mouse DMD gene including part of Intron 22 and Intron 23 but lacking Exon 23 and all of the sequence intervening the cut sites for the MDX-1/2 and MDX-13/14 meganucleases (SEQ ID NO: 176-178). Thus, we have demonstrated that a pair of meganucleases delivered by AAV can be used to delete a portion of the DMD gene in vivo from mouse muscle.

5. Conclusions

[0067] We have demonstrated that the genes encoding a pair of engineered single-chain meganucleases can be delivered to cells and organisms using recombinant AAV vectors and that meganucleases so delivered are able to cleave genomic DNA in the cell and delete fragments of DNA from the genome. We have further demonstrated that a pair of meganuclease-induced DNA breaks that do not generate compatible overhangs will not re-ligate to yield a defined sequence outcome following removal of the intervening sequence. Thus, for therapeutic applications in which a defined sequence outcome is desirable, it is preferable to use a pair of nucleases that generate identical overhangs.

TABLE-US-00008 SEQUENCE LISTING SEQ ID NO: 1 (wild-type I-CreI, Genbank Accession # PO5725)     1 MNTKYNKEFL LYLAGFVDGD GSIIAQIKPN QSYKFKHQLS LAFQVTQKTQ RRWFLDKLVD    61 EIGVGYVRDR GSVSDYILSE IKPLHNFLTQ LQPFLKLKQK QANLVLKIIW RLPSAKESPD   121 KFLEVCTWVD QIAALNDSKT RKTTSETVRA VLDSLSEKKK SSP  SEQ ID NO: 135 (DYS-1/2)     1 MAPKKKRKVH MNTKYNKEFL LYLAGFVDGD GSIYAWISPS QTCKFKHRLM LRFIVSQKTQ    61 RRWFLDKLVD EIGVGYVQDC GSVSEYRLSE IKPLHNFLTQ LQPFLKLKQK QANLVLKIIE   121 QLPSAKESPD KFLEVCTWVD QIAALNDSKT RKTTSETVRA VLDSLPGSVG GLSPSQASSA   181 ASSASSSPGS GISEALRAGA GSGTGYNKEF LLYLAGFVDG DGSIYACILP TQRQKFKHGL   241 TLYFRVTQKT QRRWFLDKLV DEIGVGYVLD FGSVSCYSLS QIKPLHNFLT QLQPFLKLKQ   301 KQANLVLKII EQLPSAKESP DKFLEVCTWV DQIAALNDSK TRKTTSETVR AVLDSLSEKK   361 KSSP  SEQ ID NO: 136 (DYS-3/4)     1 MAPKKKRKVH MNTKYNKEFL LYLAGFVDGD GSIFASIRPR QTSKFKHALA LFFVVGQKTQ    61 RRWFLDKLVD EIGVGYVYDR GSVSVYQLSQ IKPLHNFLTQ LQPFLKLKQK QANLVLKIIE   121 QLPSAKESPD KFLEVCTWVD QIAALNDSKT RKTTSETVRA VLDSLPGSVG GLSPSQASSA   181 ASSASSSPGS GISEALRAGA GSGTGYNKEF LLYLAGFVDG DGSIIACIRP HQAYKFKHQL   241 CLSFCVYQKT QRRWFLDKLV DEIGVGYVTD AGSVSSYRLS EIKPLHNFLT QLQPFLKLKQ   301 KQANLVLKII EQLPSAKESP DKFLEVCTWV DQIAALNDSK TRKTTSETVR AVLDSLSEKK   361 KSSP  SEQ ID NO: 137 (DYS-5/6)     1 MAPKKKRKVH MNTKYNKEFL LYLAGFVDGD GSIFACIQPD QRAKFKHTLR LSFEVGQKTQ    61 RRWFLDKLVD EIGVGYVNDS GSVSKYRLSQ IKPLHNFLTQ LQPFLKLKQK QANLVLKIIE   121 QLPSAKESPD KFLEVCTWVD QIAALNDSKT RKTTSETVRA VLDSLPGSVG GLSPSQASSA   181 ASSASSSPGS GISEALRAGA GSGTGYNKEF LLYLAGFVDG DGSIYATIQP TQCAKFKHQL   241 TLRFSVSQKT QRRWFLDKLV DEIGVGYVCD KGSVSEYMLS EIKPLHNFLT QLQPFLKLKQ   301 KQANLVLKII EQLPSAKESP DKFLEVCTWV DQIAALNDSK TRKTTSETVR AVLDSLSEKK   361 KSSP  SEQ ID NO: 138 (DYS-7/8)     1 MAPKKKRKVH MNTKYNKEFL LYLAGFVDGD GSIYACILPV QRCKFKHGLS LRFMVSQKTQ    61 RRWFLDKLVD EIGVGYVYDC GSVSEYRLSE IKPLHNFLTQ LQPFLKLKQK QANLVLKIIE   121 QLPSAKESPD KFLEVCTWVD QIAALNDSKT RKTTSETVRA VLDSLPGSVG GLSPSQASSA   181 ASSASSSPGS GISEALRAGA GSGTGYNKEF LLYLAGFVDG DGSIFASIVP DQRSKFKHGL   241 ALRFNVVQKT QRRWFLDKLV DEIGVGYVYD QGSVSEYRLS EIKPLHNFLT QLQPFLKLKQ   301 KQANLVLKII EQLPSAKESP DKFLEVCTWV DQIAALNDSK TRKTTSETVR AVLDSLSEKK   361 KSSP  SEQ ID NO: 139 (DYS-1/2 PCR Template for mRNA)     1 CACAGGTGTC CACTCCCAGT TCAATTACAG CTCTTAAGGC TAGAGTACTT AATACGACTC    61 ACTATAGGCT AGCCTCGAGC CGCCACCATG GCACCGAAGA AGAAGCGCAA GGTGCATATG   121 AATACAAAAT ATAATAAAGA GTTCTTACTC TACTTAGCAG GGTTTGTAGA CGGTGACGGT   181 TCCATCTATG CCTGGATCAG TCCTTCGCAA ACGTGTAAGT TCAAGCACAG GCTGATGCTC   241 CGGTTCATTG TCTCGCAGAA GACACAGCGC CGTTGGTTCC TCGACAAGCT GGTGGACGAG   301 ATCGGTGTGG GTTACGTGCA GGACTGTGGC AGCGTCTCCG AGTACCGGCT GTCCGAGATC   361 AAGCCTTTGC ATAATTTTTT AACACAACTA CAACCTTTTC TAAAACTAAA ACAAAAACAA   421 GCAAATTTAG TTTTAAAAAT TATTGAACAA CTTCCGTCAG CAAAAGAATC CCCGGACAAA   481 TTCTTAGAAG TTTGTACATG GGTGGATCAA ATTGCAGCTC TGAATGATTC GAAGACGCGT   541 AAAACAACTT CTGAAACCGT TCGTGCTGTG CTAGACAGTT TACCAGGATC CGTGGGAGGT   601 CTATCGCCAT CTCAGGCATC CAGCGCCGCA TCCTCGGCTT CCTCAAGCCC GGGTTCAGGG   661 ATCTCCGAAG CACTCAGAGC TGGAGCAGGT TCCGGCACTG GATACAACAA GGAATTCCTG   721 CTCTACCTGG CGGGCTTCGT CGACGGGGAC GGCTCCATCT ATGCCTGTAT CCTTCCGACT   781 CAGCGTCAGA AGTTCAAGCA CGGGCTGACG CTCTATTTCC GGGTCACTCA GAAGACACAG   841 CGCCGTTGGT TCCTCGACAA GCTGGTGGAC GAGATCGGTG TGGGTTACGT GCTGGACTTT   901 GGCAGCGTCT CCTGTTACTC TCTGTCCCAG ATCAAGCCTC TGCACAACTT CCTGACCCAG   961 CTCCAGCCCT TCCTGAAGCT CAAGCAGAAG CAGGCCAACC TCGTGCTGAA GATCATCGAG  1021 CAGCTGCCCT CCGCCAAGGA ATCCCCGGAC AAGTTCCTGG AGGTGTGCAC CTGGGTGGAC  1081 CAGATCGCCG CTCTGAACGA CTCCAAGACC CGCAAGACCA CTTCCGAAAC CGTCCGCGCC  1141 GTTCTAGACA GTCTCTCCGA GAAGAAGAAG TCGTCCCCCT AAACAGTCTC TCCGAGAAGA  1201 AGAAGTCGTC CCCCTAGCGG CCGCTTCGAG CAGACATGAT AAGATACATT GATGAGTTTG  1261 GACAAACCAC AACTAGAATG CAGTGAAAAA AATGCTTTAT TTGTGAAATT TGTGATGCTA  1321 TTGCTTTATT TGTAACCATT ATAAGCTGCA ATAAACAAGT TAACAACAAC AATTGCATTC  1381 ATTTTATGTT TCAGGTTCAG GGGGAGATGT GGGAGGTTTT TTAAAGCAAG TAAAACCTCT  1441 ACAAATGTGG TAAAATCGAT AAGATCTTGA TCCGGGCTGG CGTAATAGCG AAGAGGCCCG  1501 CACCGATCGC CCTTCCCAAC AGTTGCGCAG CCTGAATGGC GAATGGACGC GCCCTGTAGC  1561 GGCGCATTAA GCGCGGCGGG TGTGGTGGTT ACGCGCAGCG TGACCGCTAC ACTTGCCAGC  1621 GCCCTAGCGC CCGCTCCTTT CGCTTTCTTC CCTTCCTTTC TCGCCACGTT CGCCGGCTTT  1681 CCCCGTCAAG CTCTAAATCG GGGGCTCCCT TTAGGGTTCC GATTTAGTGC TTTACGGCAC  1741 CTCGACCCCA AAAAACTTGA TTAGGGTGAT GGTTCACGTA GTGGGCCATC G  SEQ ID NO: 140 (DYS-3/4 PCR Template for mRNA)     1 CACAGGTGTC CACTCCCAGT TCAATTACAG CTCTTAAGGC TAGAGTACTT AATACGACTC    61 ACTATAGGCT AGCCTCGAGC CGCCACCATG GCACCGAAGA AGAAGCGCAA GGTGCATATG   121 AATACAAAAT ATAATAAAGA GTTCTTACTC TACTTAGCAG GGTTTGTAGA CGGTGACGGT   181 TCCATCTTTG CCTCTATCCG GCCTCGGCAA ACGAGTAAGT TCAAGCACGC GCTGGCTCTC   241 TTTTTCGTGG TCGGGCAGAA GACACAGCGC CGTTGGTTCC TCGACAAGCT GGTGGACGAG   301 ATCGGTGTGG GTTACGTGTA TGACCGTGGC AGCGTCTCCG TGTACCAGCT GTCCCAGATC   361 AAGCCTTTGC ATAATTTTTT AACACAACTA CAACCTTTTC TAAAACTAAA ACAAAAACAA   421 GCAAATTTAG TTTTAAAAAT TATTGAACAA CTTCCGTCAG CAAAAGAATC CCCGGACAAA   481 TTCTTAGAAG TTTGTACATG GGTGGATCAA ATTGCAGCTC TGAATGATTC GAAGACGCGT   541 AAAACAACTT CTGAAACCGT TCGTGCTGTG CTAGACAGTT TACCAGGATC CGTGGGAGGT   601 CTATCGCCAT CTCAGGCATC CAGCGCCGCA TCCTCGGCTT CCTCAAGCCC GGGTTCAGGG   661 ATCTCCGAAG CACTCAGAGC TGGAGCAGGT TCCGGCACTG GATACAACAA GGAATTCCTG   721 CTCTACCTGG CGGGCTTCGT CGACGGGGAC GGCTCCATCA TTGCCTGTAT CCGGCCTCAT   781 CAAGCTTATA AGTTCAAGCA CCAGCTGTGT CTCTCTTTCT GTGTCTATCA GAAGACACAG   841 CGCCGTTGGT TCCTCGACAA GCTGGTGGAC GAGATCGGTG TGGGTTACGT GACGGACGCT   901 GGCAGCGTCT CCTCTTACCG GCTGTCCGAG ATCAAGCCTC TGCACAACTT CCTGACCCAG   961 CTCCAGCCCT TCCTGAAGCT CAAGCAGAAG CAGGCCAACC TCGTGCTGAA GATCATCGAG  1021 CAGCTGCCCT CCGCCAAGGA ATCCCCGGAC AAGTTCCTGG AGGTGTGCAC CTGGGTGGAC  1081 CAGATCGCCG CTCTGAACGA CTCCAAGACC CGCAAGACCA CTTCCGAAAC CGTCCGCGCC  1141 GTTCTAGACA GTCTCTCCGA GAAGAAGAAG TCGTCCCCCT AAACAGTCTC TCCGAGAAGA  1201 AGAAGTCGTC CCCCTAGCGG CCGCTTCGAG CAGACATGAT AAGATACATT GATGAGTTTG  1261 GACAAACCAC AACTAGAATG CAGTGAAAAA AATGCTTTAT TTGTGAAATT TGTGATGCTA  1321 TTGCTTTATT TGTAACCATT ATAAGCTGCA ATAAACAAGT TAACAACAAC AATTGCATTC  1381 ATTTTATGTT TCAGGTTCAG GGGGAGATGT GGGAGGTTTT TTAAAGCAAG TAAAACCTCT  1441 ACAAATGTGG TAAAATCGAT AAGATCTTGA TCCGGGCTGG CGTAATAGCG AAGAGGCCCG  1501 CACCGATCGC CCTTCCCAAC AGTTGCGCAG CCTGAATGGC GAATGGACGC GCCCTGTAGC  1561 GGCGCATTAA GCGCGGCGGG TGTGGTGGTT ACGCGCAGCG TGACCGCTAC ACTTGCCAGC  1621 GCCCTAGCGC CCGCTCCTTT CGCTTTCTTC CCTTCCTTTC TCGCCACGTT CGCCGGCTTT  1681 CCCCGTCAAG CTCTAAATCG GGGGCTCCCT TTAGGGTTCC GATTTAGTGC TTTACGGCAC  1741 CTCGACCCCA AAAAACTTGA TTAGGGTGAT GGTTCACGTA GTGGGCCATC G  SEQ ID NO: 141 (Exon 44 Forward PCR primer)     1 GAAAGAAAAT GCCAATAGTC CAAAATAGTT G  SEQ ID NO: 142 (Exon 44 Reverse PCR primer)     1 CATATTCAAA GGACACCACA AGTTG  SEQ ID NO: 143 (DYS-5/6 PCR Template for mRNA)     1 CACAGGTGTC CACTCCCAGT TCAATTACAG CTCTTAAGGC TAGAGTACTT AATACGACTC    61 ACTATAGGCT AGCCTCGAGC CGCCACCATG GCACCGAAGA AGAAGCGCAA GGTGCATATG   121 AATACAAAAT ATAATAAAGA GTTCTTACTC TACTTAGCAG GGTTTGTAGA CGGTGACGGT   181 TCCATCTTTG CCTGTATCCA GCCTGATCAA AGGGCGAAGT TCAAGCACAC GCTGCGGCTC   241 TCTTTCGAGG TCGGGCAGAA GACACAGCGC CGTTGGTTCC TCGACAAGCT GGTGGACGAG   301 ATCGGTGTGG GTTACGTGAA TGACTCTGGC AGCGTCTCCA AGTACAGGCT GTCCCAGATC   361 AAGCCTTTGC ATAATTTTTT AACACAACTA CAACCTTTTC TAAAACTAAA ACAAAAACAA   421 GCAAATTTAG TTTTAAAAAT TATTGAACAA CTTCCGTCAG CAAAAGAATC CCCGGACAAA   481 TTCTTAGAAG TTTGTACATG GGTGGATCAA ATTGCAGCTC TGAATGATTC GAAGACGCGT   541 AAAACAACTT CTGAAACCGT TCGTGCTGTG CTAGACAGTT TACCAGGATC CGTGGGAGGT   601 CTATCGCCAT CTCAGGCATC CAGCGCCGCA TCCTCGGCTT CCTCAAGCCC GGGTTCAGGG   661 ATCTCCGAAG CACTCAGAGC TGGAGCAGGT TCCGGCACTG GATACAACAA GGAATTCCTG   721 CTCTACCTGG CGGGCTTCGT CGACGGGGAC GGCTCCATCT ATGCCACTAT CCAGCCTACT   781 CAATGTGCGA AGTTCAAGCA CCAGCTGACT CTCCGTTTCT CGGTCTCTCA GAAGACACAG   841 CGCCGTTGGT TCCTCGACAA GCTGGTGGAC GAGATCGGTG TGGGTTACGT GTGTGACAAG   901 GGCAGCGTCT CCGAGTACAT GCTGTCCGAG ATCAAGCCTC TGCACAACTT CCTGACCCAG   961 CTCCAGCCCT TCCTGAAGCT CAAGCAGAAG CAGGCCAACC TCGTGCTGAA GATCATCGAG  1021 CAGCTGCCCT CCGCCAAGGA ATCCCCGGAC AAGTTCCTGG AGGTGTGCAC CTGGGTGGAC  1081 CAGATCGCCG CTCTGAACGA CTCCAAGACC CGCAAGACCA CTTCCGAAAC CGTCCGCGCC  1141 GTTCTAGACA GTCTCTCCGA GAAGAAGAAG TCGTCCCCCT AAACAGTCTC TCCGAGAAGA  1201 AGAAGTCGTC CCCCTAGCGG CCGCTTCGAG CAGACATGAT AAGATACATT GATGAGTTTG  1261 GACAAACCAC AACTAGAATG CAGTGAAAAA AATGCTTTAT TTGTGAAATT TGTGATGCTA  1321 TTGCTTTATT TGTAACCATT ATAAGCTGCA ATAAACAAGT TAACAACAAC AATTGCATTC  1381 ATTTTATGTT TCAGGTTCAG GGGGAGATGT GGGAGGTTTT TTAAAGCAAG TAAAACCTCT  1441 ACAAATGTGG TAAAATCGAT AAGATCTTGA TCCGGGCTGG CGTAATAGCG AAGAGGCCCG  1501 CACCGATCGC CCTTCCCAAC AGTTGCGCAG CCTGAATGGC GAATGGACGC GCCCTGTAGC  1561 GGCGCATTAA GCGCGGCGGG TGTGGTGGTT ACGCGCAGCG TGACCGCTAC ACTTGCCAGC  1621 GCCCTAGCGC CCGCTCCTTT CGCTTTCTTC CCTTCCTTTC TCGCCACGTT CGCCGGCTTT  1681 CCCCGTCAAG CTCTAAATCG GGGGCTCCCT TTAGGGTTCC GATTTAGTGC TTTACGGCAC  1741 CTCGACCCCA AAAAACTTGA TTAGGGTGAT GGTTCACGTA GTGGGCCATC G  SEQ ID NO: 144 (DYS-7/8 PCR Template for mRNA)     1 CACAGGTGTC CACTCCCAGT TCAATTACAG CTCTTAAGGC TAGAGTACTT AATACGACTC    61 ACTATAGGCT AGCCTCGAGC CGCCACCATG GCACCGAAGA AGAAGCGCAA GGTGCATATG   121 AATACAAAAT ATAATAAAGA GTTCTTACTC TACTTAGCAG GGTTTGTAGA CGGTGACGGT   181 TCCATCTATG CCTGTATCTT GCCGGTGCAG CGTTGTAAGT TCAAGCACGG GCTGTCTCTC   241 CGATTCATGG TCAGTCAGAA GACACAGCGC CGTTGGTTCC TCGACAAGCT GGTGGACGAG   301 ATCGGTGTGG GTTACGTGTA TGACTGTGGC AGCGTCTCCG AGTACAGGCT GTCCGAGATC   361 AAGCCTTTGC ATAATTTTTT AACACAACTA CAACCTTTTC TAAAACTAAA ACAAAAACAA   421 GCAAATTTAG TTTTAAAAAT TATTGAACAA CTTCCGTCAG CAAAAGAATC CCCGGACAAA   481 TTCTTAGAAG TTTGTACATG GGTGGATCAA ATTGCAGCTC TGAATGATTC GAAGACGCGT   541 AAAACAACTT CTGAAACCGT TCGTGCTGTG CTAGACAGTT TACCAGGATC CGTGGGAGGT   601 CTATCGCCAT CTCAGGCATC CAGCGCCGCA TCCTCGGCTT CCTCAAGCCC GGGTTCAGGG   661 ATCTCCGAAG CACTCAGAGC TGGAGCAGGT TCCGGCACTG GATACAACAA GGAATTCCTG   721 CTCTACCTGG CGGGCTTCGT CGACGGGGAC GGCTCCATCT TTGCCTCTAT CGTGCCGGAT   781 CAGCGTAGTA AGTTCAAGCA CGGTCTGGCT CTCAGGTTCA ATGTCGTTCA GAAGACACAG   841 CGCCGTTGGT TCCTCGACAA GCTGGTGGAC GAGATCGGTG TGGGTTACGT GTATGACCAG   901 GGCAGCGTCT CCGAGTACAG GCTGTCCGAG ATCAAGCCTC TGCACAACTT CCTGACCCAG   961 CTCCAGCCCT TCCTGAAGCT CAAGCAGAAG CAGGCCAACC TCGTGCTGAA GATCATCGAG  1021 CAGCTGCCCT CCGCCAAGGA ATCCCCGGAC AAGTTCCTGG AGGTGTGCAC CTGGGTGGAC  1081 CAGATCGCCG CTCTGAACGA CTCCAAGACC CGCAAGACCA CTTCCGAAAC CGTCCGCGCC  1141 GTTCTAGACA GTCTCTCCGA GAAGAAGAAG TCGTCCCCCT AAACAGTCTC TCCGAGAAGA  1201 AGAAGTCGTC CCCCTAGCGG CCGCTTCGAG CAGACATGAT AAGATACATT GATGAGTTTG  1261 GACAAACCAC AACTAGAATG CAGTGAAAAA AATGCTTTAT TTGTGAAATT TGTGATGCTA  1321 TTGCTTTATT TGTAACCATT ATAAGCTGCA ATAAACAAGT TAACAACAAC AATTGCATTC  1381 ATTTTATGTT TCAGGTTCAG GGGGAGATGT GGGAGGTTTT TTAAAGCAAG TAAAACCTCT  1441 ACAAATGTGG TAAAATCGAT AAGATCTTGA TCCGGGCTGG CGTAATAGCG AAGAGGCCCG  1501 CACCGATCGC CCTTCCCAAC AGTTGCGCAG CCTGAATGGC GAATGGACGC GCCCTGTAGC  1561 GGCGCATTAA GCGCGGCGGG TGTGGTGGTT ACGCGCAGCG TGACCGCTAC ACTTGCCAGC  1621 GCCCTAGCGC CCGCTCCTTT CGCTTTCTTC CCTTCCTTTC TCGCCACGTT CGCCGGCTTT  1681 CCCCGTCAAG CTCTAAATCG GGGGCTCCCT TTAGGGTTCC GATTTAGTGC TTTACGGCAC  1741 CTCGACCCCA AAAAACTTGA TTAGGGTGAT GGTTCACGTA GTGGGCCATC G  SEQ ID NO: 145 (Exon 45 Forward PCR primer)     1 CTAACCGAGA GGGTGCTTTT TTC  SEQ ID NO: 146 (Exon 45 Reverse PCR primer)     1 GTGTTTAGGT CAACTAATGT GTTTATTTTG  SEQ ID NO: 147 (MDX-1/2 Meganuclease)     1 MAPKKKRKVH MNTKYNKEFL LYLAGFVDGD GSIFACIHPS QAYKFKHRLT LHFTVTQKTQ    61 RRWFLDKLVD EIGVGYVQDV GSVSQYRLSQ IKPLHNFLTQ LQPFLKLKQK QANLVLKIIE   121 QLPSAKESPD KFLEVCTWVD QIAALNDSKT RKTTSETVRA VLDSLPGSVG GLSPSQASSA   181 ASSASSSPGS GISEALRAGA GSGTGYNKEF LLYLAGFVDG DGSISATIAP AQYGKFKHYL   241 GLRFYVSQKT QRRWFLDKLV DEIGVGYVSD QGSVSRYCLS QIKPLHNFLT QLQPFLKLKQ   301 KQANLVLKII EQLPSAKESP DKFLEVCTWV DQIAALNDSK TRKTTSETVR AVLDSLSEKK   361 KSSP  SEQ ID NO: 148 (MDX-13/14 Meganuclease)     1 MAPKKKRKVH MNTKYNKEFL LYLAGFVDGD GSIYACIRPT QSVKFKHDLL LCFDVSQKTQ    61 RRWFLDKLVD EIGVGYVYDR GSVSSYRLSE IKPLHNFLTQ LQPFLKLKQK QANLVLKIIE   121 QLPSAKESPD KFLEVCTWVD QIAALNDSKT RKTTSETVRA VLDSLPGSVG GLSPSQASSA   181 ASSASSSPGS GISEALRAGA GSGTGYNKEF LLYLAGFVDG DGSIWASIEP RQQSKFKHQL   241 RLGFSVYQKT QRRWFLDKLV DEIGVGYVRD TGSVSCYCLS QIKPLHNFLT QLQPFLKLKQ   301 KQANLVLKII EQLPSAKESP DKFLEVCTWV DQIAALNDSK TRKTTSETVR AVLDSLSEKK   361 KSSP  SEQ ID NO: 149 (MDX-1/2 Recognition Sequence)     1 TTCTGTGATG TGAGGACATA TA  SEQ ID NO: 150 (MDX-13/14 Recognition Sequence)     1 ACTAATGAAA CACCACTCCA CA  SEQ ID NO: 151 (Mouse DMD Intron 22 Forward Primer)     1 GTCTTATCAG TCAAGAGATC ATATTG  SEQ ID NO: 152 (Mouse DMD Intron 23 Reverse Primer)     1 GTGTCAGTAA TCTCTATCCC TTTCATG     SEQ ID NO: 153 (Mutant Sequence from Mouse DMD Gene)     1 AGAATTTAAA TATTAACAAA CTATAACACT ATGATTAAAT GCTTGATATT GAGTAGTTAT    61 TTTAATAGCC TAAGTCTGGA AATTAAATAC TAGTAAGAGA AACTTCTAGA ATTTAAATAT   121 TAACAAACTA TAACACTATG ATTAAATGCT TGATATTGAG TAGTTATTTT AATAGCCTAA   181 GTCTGGAAAT TAAATACTAG TAAGAGAAAC TTCT  SEQ ID NO: 154 (Mutant Sequence from Mouse DMD Gene)     1 TTTAATAGCC TAAGTCTGGA AATACTCCAC AGGTGATTTC AGCCACTTTA TGAACTGCTG    61 GAAGCAAAAA TGAGATCTTT  SEQ ID NO: 155 (Mutant Sequence from Mouse DMD Gene)     1 TTAGTTAGAA TTTAAATATT AACAAACTAT AACACTATGA TTAAATGCTT GATATTGAGT    61 AGTTATTTTA ATAGCCTAAG TCTGGAAATT AAATACTAGT AAGAGAAACT TCTGTGATGT   121 GACCACTCCA CAGGTGATTT CAGCCACTTT ATGAACTGCT GGAAGCAAAA ATGAGATCTT   181 T  SEQ ID NO: 156 (Mutant Sequence from Mouse DMD Gene)     1 TATAACACTA TGATTAAATG CTTGATATTG AGTAGTTATT TTATGTGTCA TACCTTCTTG    61 GATTGTCTGT ATAAATGAAT TGATTTTTTT TCACCAACTC CAAGTATACT TAACATTTTA   121 ACATAATAAT TTAAAATATC CTTATTCCAT TATGTTCATT TTTTAAGTTG TAGATATGAT   181 TTAGCTCACA GCATACATAT ATACACATGT ATTACATATG CATATATTAT ATATATGGCA   241 GACATATGTT TTCACTACCA TATTTCACTT TTGAATTATG AATATATGTT TAATTTCTGC   301 CATATTTCCT TCCCTACATT GACTTCTATT AATTTAGTAT TTCAGTAGTT CTAACACATT   361 AATAATAACC TAGACTCAAT ACAGTAATCT AACAATTATA TTTGTGCCTG TAATTCTAAG   421 TTAGTTAAAT TCATAGGTTG TGTTTCTCAT AGTTGGCCAT TTGTGAAATA TAATAATATC   481 CGAAAAGAAA GTTCAAAAAT GTCATGACTT CATATAGAGT TATTGAAACA GTGCCCTTAC   541 TTTCATTCTG GCCATGCTAG TGACTTGATC ATTCTTGTAT TTTACAGCTA AAACACTACC   601 AAAAGTGTCA AATCCATGAT CTACATGTTT GACCACTCCA CAGGTGATTT CAGCCACTTT   661 ATGAACTGCT GGAAGCAAAA ATGAGATCTT T  SEQ ID NO: 157 (Mutant Sequence from Mouse DMD Gene)     1 TTGAGTAGTT ATTTTAATAG CCTAAGTCTG GAAATTAAAT ACTAGTAAGA GAAACTTCTG    61 TGATGTGCAC AGGTGATTTC AGCCACTTTA TGAACTGCTG GAAGCAAAAA TG  SEQ ID NO: 158 (Mutant Sequence from Mouse DMD Gene)     1 GATATTGAGT AGTTATTTTA ATAGCCTAAG TCTGGAAATT AAATACTAGT AGATTTCAGC    61 CACTTTATGA ACTGCTGGAA GCAAAAATGA  SEQ ID NO: 159 (Mutant Sequence from Mouse DMD Gene)     1 AATACTAGTA AGAGAAACTT CTGTGATGTG AGGACTCCAC AGGTGATTTC AGCCACTTTA    61 TGAACTGCTG GAAGCAAAAA TGAGATCTTT GCAACATGAA GCAGTTGCTC AGTTCATTAA   121 ACTGTGTTCA ATATTTCAGC CATAACATAC ATTAGAGAAT GATTTATATT GTTCAAACAT   181 TT  SEQ ID NO: 160 (Mutant Sequence from Mouse DMD Gene)     1 AATACTAGTA AGAGAAACTT CTGTGATGTG AGGACATTTC AGCCACTTTA TGAACTGCTG    61 GAAGCAAAAA TGAGATCTTT GCAACATGAA GCAGTTGCTC AGTTCATTAA ACTGTGTTCA   121 ATATTTCAGC CATAACATAC ATTAGAGAAT GATTTATATT GTTCAAACAT TT  SEQ ID NO: 161 (Mutant Sequence from Mouse DMD Gene)     1 AATACTAGTA AGAGAAGATT TCAGCCACTT TATGAACTGC TGGAAGCAAA AATGAGATCT    61 TTGCAACATG AAGCAGTTGC TCAGTTCATT AAACTGTGTT CAATATTTCA GCCATAACAT   121 ACATTAGAGA ATGATTTATA TTGTTCAAAC ATTT  SEQ ID NO: 162 (Mutant Sequence from Mouse DMD Gene)     1 TTTAATAGCC TAAGTCTGGA AATTAAATAC TAGTAAGAGA GTGATTTCAG CCACTTTATG    61 AACTGCTGGA AGCAAAAATG A  SEQ ID NO: 163 (Mutant Sequence from Mouse DMD Gene)     1 TTAGTTAGAA TTTAAATATT AACAAACTAT AACACTATGA TTAAATGCTT GATATTGAGT    61 AGTTATTTTA ATAGCCTAAG TCTGGAAATT AAATACTAGT TCAGCCACTT TATGAACTGC   121 TGGAAGCAAA AATGAGATCT CATTAAACTG TGTTCAATAT TTCAGCCATA ACATACATTA   181 GAGAATGATT TATATTGTTC AAACATTTGG TGCTCTATTT TTGCATGACG TGGGA  SEQ ID NO: 164 (Mutant Sequence from Mouse DMD Gene)     1 TTAGTTAGAA TTTAAATATT AACAAACTAT AACACTATGA TTAAATGCTT GATATTGAGT    61 AGTTATTTTA ATAGCCTAAG TCTGGAAATT AAATACTAGT AAGAGAAACT TCTGTGATGT   121 GAGGACATAT AAAGACTAAT TTTTTTGTTG ATTCTAAAAA TCCACAGGTG ATTTCAGCCA   181 CTTTATGAAC TGCTGGAAGC AAAAATGAGA TCTTTGCAAC ATGAAGCAGT TGCTCAGTTC   241 ATTAAACTGT GTTCAATATT TCAGCCATAA CATACATTAG AGAATGATTT ATATTGTTCA   301 AACATTTGGT GCTCTATTTT TGCATGACGT GGGA  SEQ ID NO: 165 (Mutant Sequence from Mouse DMD Gene)     1 TTAGTTAGAA TTTAAATATT AACAAACTAT AACACTATGA TTAAATGCTT GATATTGAGT    61 AGTTATTTTA ATAGCCTAAG TCTGGAAATT AAATACTAGT AAGAGAAACT TCTGTGATGT   121 GAGGACATAT AAAGACTAAT TTTTTCACTC CACAGGTGAT TTCAGCCACT TTATGAACTG   181 CTGGAAGCAA AAATGAGATC TTT  SEQ ID NO: 166 (Mutant Sequence from Mouse DMD Gene)     1 TTATTTTAAT AGCCTAAGTC TGGAAATTAA ATACTAGTAA GAGAAACTTC TGTGATGTGA    61 GGACATATAA AGACTAATTT TTTTGTTGAT TCTAAAAATC CCATGTTGTA TACTTATTCT   121 TTTTAAATCT GAAAATATAT TAATCATATA TTGCCTAAAT GTCTTAATAA TGTTTCACTG   181 TAGGTAAGTT AAAATGTATC ACATATATAA TAAACATAGT TATTAATGCA TAGATATTCA   241 GTAAAATTAT GACTTCTAAA TTTCTGTCTA AATATAATAT GCCCTGTAAT ATAATAGAAA   301 TTATTCATAA GAATACATAT ATATTGCTTT ATCAGATATT CTACTTTGTT TAGATCTCTA   361 AATTACATAA ACTTTTATTT ACCTTCTTCT TGATATGAAT GAAACTCATC AAATATGCGT   421 GTTAGTGTAA ATGAACTTCT ATTTAAACTC CACAGGTGAT TTCAGCCACT TTATGAAC  SEQ ID NO: 167 (Mutant Sequence from Mouse DMD Gene)     1 TTAGTTAGAA TTTAAATATT AACAAACTAT AACACTATGA TTAAATGCTT GATATTGAGT    61 AGTTATTTTA ATAGCCTAAG TCTGGAAATT AAATACTAGT AAGAGAAACT TCTGTGATGT   121 GAGGACATAT AAAGACTAAT TTTTTTGTTG ATTCTAAAAA TCCCATGTTG TATACTTATT   181 CTTTTTAAAT CTGAAAATAT ATTAATCATA TATTGCCTAA ATGTCTTAAT AATGTTTCAC   241 TGTAGGTAAG TTAAAATGTA TCACATATAT AATAAACATA GTTATTAATG CATAGATATT   301 CAGTAAAATT ATGACTTCTA AATTTCTGTC TAAATATAAT ATGCCCTGTA ATATAATAGA   361 AATTATTCAT AAGAATACAT ATATATTGCT TTATCAGATA TTCTACTTTG TTTAGATCTC   421 TAAATTACAT AAACTTTTAT TTACCTTCTT CTTGATATGA ATGAAACTCA TCAAATATGC   481 GTGTTAGTGT AAATGAACTT CTATTTAATT TTGAGGCTCT GCAAAGTTCT CCACAGGTGA   541 TTTCAGCCAC TTTATGAACT GCTGGAAGCA AAAATGAGAT CTTTGCAACA TGAAGCAGTT   601 GCTCAGTTCA TTAAACTGTG TTCAATATTT CAGCCATAAC ATACATTAGA GAATGATTTA   661 TATTGTTCAA ACATTTGGTG CTCTATTTTT GCATGACGTG GGA  SEQ ID NO: 168 (Mutant Sequence from Mouse DMD Gene)     1 AATACTAGTA AGAGAAACTT CTGTGATGTG AGGACATATA AAGACTAATT TTTTTGTTGA    61 TTCTAAAAAT CCCATGTTGT ATACTTATTC TTTTTAAATC TGAAAATATA TTAATCATAT   121 ATTGCCTAAA TGTCTTAATA ATGTTTCACT GTAGGTAAGT TAAAATGTAT CACATATATA   181 ATAAACATAG TTATTAATGC ATAGATATTC AGTAAAATTA TGACTTCTAA ATTTCTGTCT   241 AAATATAATA TGCCCTGTAA TATAATAGAA ATTATTCATA AGAATACATA TATATTGCTT   301 TATCAGATAT TCTACTTTGT TTAGATCTCT AAATTACATA AACTTTTATT TACCTTCTTC   361 TTGATATGAA TGAAACTCAT CAAATATGCG TGTTAGTGTA AATGAACTTC TATTTAATTT   421 TGAGGCTCTG CAAAGTTCTT TGAAAGAGCA ACAAAATGGC TTCACCACTC CACAGGTGAT   481 TTCAGCCACT TTATGAACTG CTGGAAGCAA AAATGAGATC TTTGCAACAT GAAGCAGTTG   541 CTCAGTTCAT TAAACTGTGT TCAATATTTC AGCCATAACA TACATTAGAG AATGATTTAT   601 ATTGTTCAAA CATTT  SEQ ID NO: 169 (Mutant SequencefromMouseDMD Gene)     1 TTAGTTAGAA TTTAAATATT AACAAACTAT AACACTATGA TTAAATGCTT GATATTGAGT    61 AGTTATTTTA ATAGCCTAAG TCTGGAAATT AAATACTAGT AAGAGAAACT TCTGTGATGT   121 GAGGACATAT AAAGACTAAT TTTTTTGTTG ATTCTAAAAA TCCCATGTTG TATACTTATT   181 CTTTTTAAAT CTGAAAATAT ATTAATCATA TATTGCCTAA ATGTCTTAAT AATGTTTCAC   241 TGTAGGTAAG TTAAAATGTA TCACATATAT AATAAACATA GTTATTAATG CATAGATATT   301 CAGTAAAATT ATGACTTCTA AATTTCTGTC TAAATATAAT ATGCCCTGTA ATATAATAGA   361 AATTATTCAT AAGAATACAT ATATATTGCT TTATCAGATA TTCTACTTTG TTTAGATCTC   421 TAAATTACAT AAACTTTTAT TTACCTTCTT CTTGATATGA ATGAAACTCA TCAAATATGC   481 GTGTTAGTGT AAATGAACTT CTATTTAATT TTGAGGCTCT GCAAAGTTCT TTGAAAGAGC   541 AACAAAATGG CTTCAACTAT CTGAGTGACA CTGTGAAGGA GATGGCCAAG AAAGCACCTT   601 CAGAAATATG CCATTTCAGC CACTTTATGA ACTGCTGGAA GCAAAAATGA GATCTTTGCA   661 ACATGAAGCA GTTGCTCAGT TCATTAAACT GTGTTCAATA TTTCAGCCAT AACATACATT   721 AGAGAATGAT TTATATTGTT CAAACATTTG GTGCTCTATT TTTGCATGAC GTGGGA  SEQ ID NO: 170 (Mutant Sequence from Mouse DMD Gene)     1 GTCTGGAAAT TAAATACTAG TAAGAGAAAC TTCTGTGATG TGAGGACATA TAAAGACTAA    61 TTTTTTTGTT GATTCTAAAA ATCCCATGTT GTATACTTAT TCTTTTTAAA TCTGAAAATA   121 TATTAATCAT ATATTGCCTA AATGTCTTAA TAATGTTTCA CTGTAGGTAA GTTAAAATGT   181 ATCACATATA TAATAAACAT AGTTATTAAT GCATAGATAT TCAGTAAAAT TATGACTTCT   241 AAATTTCTGT CTAAATATAA TATGCCCTGT AATATAATAG AAATTATTCA TAAGAATACA   301 TATATATTGC TTTATCAGAT ATTCTACTTT GTTTAGATCT CTAAATTACA TAAACTTTTA   361 TTTACCTTCT TCTTGATATG AATGAAACTC ATCAAATATG CGTGTTAGTG TAAATGAACT   421 TCTATTTAAT TTTGAGGCTC TGCAAAGTTC TTTGAAAGAG CAACAAAATG GCTTCAACTA   481 TCTGAGTGAC ACTGTGAAGG AGATGGCCAA GAAAGCACCT TCAGAAATAT GCCAGAAATA   541 TCTGTCAGAA TTTGAAGAGA TTGAGGGGCA CTGGAAGAAA CTTTCCTCCC AGTTGGTGGA   601 AAACACCACT CCACAGGTGA TTTCAGCCAC TTTAT  SEQ ID NO: 171 (Mutant Sequence from Mouse DMD Gene)     1 TGGAAATTAA ATACTAGTAA GAGAAACTTC TGTGATGTGA GGACATATAA AGACTAATTT    61 TTTTGTTGAT TCTAAAAATC CCATGTTGTA TACTTATTCT TTTTAAATCT GAAAATATAT   121 TAATCATATA TTGCCTAAAT GTCTTAATAA TGTTTCACTG TAGGTAAGTT AAAATGTATC   181 ACATATATAA TAAACATAGT TATTAATGCA TAGATATTCA GTAAAATTAT GACTTCTAAA   241 TTTCTGTCTA AATATAATAT GCCCTGTAAT ATAATAGAAA TTATTCATAA GAATACATAT   301 ATATTGCTTT ATCAGATATT CTACTTTGTT TAGATCTCTA AATTACATAA ACTTTTATTT   361 ACCTTCTTCT TGATATGAAT GAAACTCATC AAATATGCGT GTTAGTGTAA ATGAACTTCT   421 ATTTAATTTT GAGGCTCTGC AAAGTTCTTT GAAAGAGCAA CAAAATGGCT TCAACTATCT   481 GAGTGACACT GTGAAGGAGA TGGCCAAGAA AGCACCTTCA GAAATATGCC AGAAATATCT   541 GTCAGAATTT GAAGAGATTG AGGGGCACTG GAAGAAACTT TCCTCCCAGT TGGTGGAAAG   601 CTGCCAAAAG CTAGAAGAAC ATATGAATAA ACTTCGAAAA TTTCAGGTAA GCCGAGGTTT   661 GGCCTTTAAA CTATATTTTT CCACTCCACA GGTGATTTCA GCCACTTTAT GAAC  SEQ ID NO: 172 (Mutant Sequence from Mouse DMD Gene)     1 CCTAAGTCTG GAAATTAAAT ACTAGTAAGA GAAACTTCTG TGATGTGAGG ACATATAAAG    61 ACTAATTTTT TTGTTGATTC TAAAAATCCC ATGTTGTATA CTTATTCTTT TTAAATCTGA   121 AAATATATTA ATCATATATT GCCTAAATGT CTTAATAATG TTTCACTGTA GGTAAGTTAA   181 AATGTATCAC ATATATAATA AACATAGTTA TTAATGCATA GATATTCAGT AAAATTATGA   241 CTTCTAAATT TCTGTCTAAA TATAATATGC CCTGTAATAT AATAGAAATT ATTCATAAGA   301 ATACATATAT ATTGCTTTAT CAGATATTCT ACTTTGTTTA GATCTCTAAA TTACATAAAC   361 TTTTATTTAC CTTCTTCTTG ATATGAATGA AACTCATCAA ATATGCGTGT TAGTGTAAAT   421 GAACTTCTAT TTAATTTTGA GGCTCTGCAA AGTTCTTTGA AAGAGCAACA AAATGGCTTC   481 AACTATCTGA GTGACACTGT GAAGGAGATG GCCAAGAAAG CACCTTCAGA AATATGCCAG   541 AAATATCTGT CAGAATTTGA AGAGATTGAG GGGCACTGGA AGAAACTTTC CTCCCAGTTG   601 GTGGAAAGCT GCCAAAAGCT AGAAGAACAT ATGAATAAAC TTCGAAAATT TCAGGTAAGC   661 CGAGGTTTGG CCTTTAAACT ATATTTTTTC ACATAGCAAT TAATTGGAAA ATGTGATGGG   721 AAACAGATAT TTTACCCAGA GTCCTTCAAA GATATTGATG ATATCAAAAG CCAAATCTAT   781 TTCAAAGGAT TGCAACTTGC CTATTTTTCC TATGAAAACA GTAATGTGTC ATACCTTCTT   841 GGATTGTCTG TATAAATGAA TTGATTTTTT TTCACCAACT CCAAGTATAC TTAACATTTT   901 AACATAATAA TTTAAAATAT CCTTATTCCA TTATGTTCAT TTTTTAAGTT GTAGATATGA   961 TTTAGCTCAC AGCATACATA TATACACATG TATTACATAT GCATATATTA TATATATGGC  1021 AGACATATGT TTTCACTACC ATATTTCACT TTTGAATTAT GAATATATGT TTAATTTCTG  1081 CCATATTTCC TTCCCTACAT TGACTTCTAT TAATTTAGTA TTTCAGTAGT TCTAACACAT  1141 TAATAATAAC CTAGACTCAA TACAGTAATC TAACAATTAT ATTTGTGCCT GTAATTCTAA  1201 GTTAGTTAAA TTCATAGGTT GTGTTTCTCA TAGTTGGCCA TTTGTGAAAT ATAATAATAT  1261 CCGAAAAGAA AGTTCAAAAA TGTCATGACT TCATATAGAC AGGTGATTTC AGCCACTTTA  1321 TG  SEQ ID NO: 173 (pAAV-MDX Plasmid)     1 GGGGGGGGGG GGGGGGGTTG GCCACTCCCT CTCTGCGCGC TCGCTCGCTC ACTGAGGCCG    61 GGCGACCAAA GGTCGCCCGA CGCCCGGGCT TTGCCCGGGC GGCCTCAGTG AGCGAGCGAG   121 CGCGCAGAGA GGGAGTGGCC AACTCCATCA CTAGGGGTTC CTAGATCTTC AATATTGGGT   181 ATTAGTCATC GCTATTACCA TGATGATGCG GTTTTGGCAG TACACCAATG GGCGTGGATA   241 GCGGTTTGAC TCACGGGGAT TTCCAAGTCT CCACCCCATT GACGTCAATG GGAGTTTGTT   301 TTGGCACCAA AATCAACGGG ACTTTCCAAA ATGTCGTAAT AACCCCGCCC CGTTGACGCA   361 AATGGGCGGT AGGCGTGTAC GGTGGGAGGT CTATATAAGC AGAGCTCGTT TAGTGAACCG   421 TCAGATCACT AGAAGCTTTA TTGCGGTAGT TTATCACAGT TAAATTGCTA GCGCAGTCAG   481 TGCTTCTGAC ACAACAGTCT CGAACTTAAG CTGCAGAAGT TGGTCGTGAG GCACTGGGCA   541 GGTAAGTATC AAGGTTACAA GACAGGTTTA AGGACACCAA TAGAAACTGG GCTTGTCGAG   601 ACAGAGAAGA CTCTTGCGTT TCTGATAGGC ACCTATTGGT CTTACTGACA TCCACTTTGC   661 CTTTCTCTCC ACAGGTAATT GTGAGCGGAT AACAATTGAT GTCGCACAGG CCACGGATTA   721 GGCACCCCAG GCTTGACACT TTATGCTTCC GGCTCGTATA TTGTGTGGAA TTGTGAGCGG   781 ATAACAATTT CACACAGGAG ATATATATAT GGGCTAGGCC ACCATGGCAC CGAAGAAGAA   841 GCGCAAGGTG CATATGAATA CAAAATATAA TAAAGAGTTC TTACTCTACT TAGCAGGGTT   901 TGTAGACGGT GACGGTTCCA TCTTTGCCTG TATCCATCCT AGTCAAGCGT ATAAGTTCAA   961 GCACCGGCTG ACTCTCCATT TCACGGTCAC TCAGAAGACA CAGCGCCGTT GGTTCCTCGA  1021 CAAGCTGGTG GACGAGATCG GTGTGGGTTA CGTGCAGGAC GTGGGCAGCG TCTCCCAGTA  1081 CCGGCTGTCC CAGATCAAGC CTTTGCATAA TTTTTTAACA CAACTACAAC CTTTTCTAAA  1141 ACTAAAACAA AAACAAGCAA ATTTAGTTTT AAAAATTATT GAACAACTTC CGTCAGCAAA  1201 AGAATCCCCG GACAAATTCT TAGAAGTTTG TACATGGGTG GATCAAATTG CAGCTCTGAA  1261 TGATTCGAAG ACGCGTAAAA CAACTTCTGA AACCGTTCGT GCTGTGCTAG ACAGTTTACC  1321 AGGATCCGTG GGAGGTCTAT CGCCATCTCA GGCATCCAGC GCCGCATCCT CGGCTTCCTC  1381 AAGCCCGGGT TCAGGGATCT CCGAAGCACT CAGAGCTGGA GCAGGTTCCG GCACTGGATA  1441 CAACAAGGAA TTCCTGCTCT ACCTGGCGGG CTTCGTCGAC GGGGACGGCT CCATCTCTGC  1501 CACTATCGCT CCGGCTCAGT ATGGTAAGTT CAAGCACTAT CTGGGGCTCC GGTTCTATGT  1561 CAGTCAGAAG ACACAGCGCC GTTGGTTCCT CGACAAGCTG GTGGACGAGA TCGGTGTGGG  1621 TTACGTGAGT GACCAGGGCA GCGTCTCCAG GTACTGTCTG TCCCAGATCA AGCCTCTGCA  1681 CAACTTCCTG ACCCAGCTCC AGCCCTTCCT GAAGCTCAAG CAGAAGCAGG CCAACCTCGT  1741 GCTGAAGATC ATCGAGCAGC TGCCCTCCGC CAAGGAATCC CCGGACAAGT TCCTGGAGGT  1801 GTGCACCTGG GTGGACCAGA TCGCCGCTCT GAACGACTCC AAGACCCGCA AGACCACTTC  1861 CGAAACCGTC CGCGCCGTTC TAGACAGTCT CTCCGAGAAG AAGAAGTCGT CCCCCTAAGG  1921 TACCAGCGGC CGCTTCGAGC AGACATGATA AGATACATTG ATGAGTTTGG ACAAACCACA  1981 ACTAGAATGC AGTGAAAAAA ATGCTTTATT TGTGAAATTT GTGATGCTAT TGCTTTATTT  2041 GTAACCATTA TAAGCTGCAA TAAACAAGTT GTATTAGTCA TCGCTATTAC CATGATGATG  2101 CGGTTTTGGC AGTACACCAA TGGGCGTGGA TAGCGGTTTG ACTCACGGGG ATTTCCAAGT  2161 CTCCACCCCA TTGACGTCAA TGGGAGTTTG TTTTGGCACC AAAATCAACG GGACTTTCCA  2221 AAATGTCGTA ATAACCCCGC CCCGTTGACG CAAATGGGCG GTAGGCGTGT ACGGTGGGAG  2281 GTCTATATAA GCAGAGCTCG TTTAGTGAAC CGTCAGATCA CTAGAAGCTT TATTGCGGTA  2341 GTTTATCACA GTTAAATTGC TAGCGCAGTC AGTGCTTCTG ACACAACAGT CTCGAACTTA  2401 AGCTGCAGAA GTTGGTCGTG AGGCACTGGG CAGGTAAGTA TCAAGGTTAC AAGACAGGTT  2461 TAAGGACACC AATAGAAACT GGGCTTGTCG AGACAGAGAA GACTCTTGCG TTTCTGATAG  2521 GCACCTATTG GTCTTACTGA CATCCACTTT GCCTTTCTCT CCACAGGTAA TTGTGAGCGG  2581 ATAACAATTG ATGTCGCACA GGCCACGGAT TAGGCACCCC AGGCTTGACA CTTTATGCTT  2641 CCGGCTCGTA TATTGTGTGG AATTGTGAGC GGATAACAAT TTCACACAGG AGATATATAT  2701 ATGGGCTAGG CCACCATGGC ACCGAAGAAG AAGCGCAAGG TGCATATGAA TACAAAATAT  2761 AATAAAGAGT TCTTACTCTA CTTAGCAGGG TTTGTAGACG GTGACGGTTC CATCTATGCC  2821 TGTATCAGGC CGACGCAGAG TGTGAAGTTC AAGCACGATC TGCTGCTCTG TTTCGATGTC  2881 TCTCAGAAGA CACAGCGCCG TTGGTTCCTC GACAAGCTGG TGGACGAGAT CGGTGTGGGT  2941 TACGTGTATG ACCGTGGCAG CGTCTCCTCG TACAGGCTGT CCGAGATCAA GCCTTTGCAT  3001 AATTTTTTAA CACAACTACA ACCTTTTCTA AAACTAAAAC AAAAACAAGC AAATTTAGTT  3061 TTAAAAATTA TTGAACAACT TCCGTCAGCA AAAGAATCCC CGGACAAATT CTTAGAAGTT  3121 TGTACATGGG TGGATCAAAT TGCAGCTCTG AATGATTCGA AGACGCGTAA AACAACTTCT  3181 GAAACCGTTC GTGCTGTGCT AGACAGTTTA CCAGGATCCG TGGGAGGTCT ATCGCCATCT  3241 CAGGCATCCA GCGCCGCATC CTCGGCTTCC TCAAGCCCGG GTTCAGGGAT CTCCGAAGCA  3301 CTCAGAGCTG GAGCAGGTTC CGGCACTGGA TACAACAAGG AATTCCTGCT CTACCTGGCG  3361 GGCTTCGTCG ACGGGGACGG CTCCATCTGG GCCTCGATCG AGCCTAGGCA ACAGTCTAAG  3421 TTCAAGCACC AGCTGCGGCT CGGGTTCTCG GTCTATCAGA AGACACAGCG CCGTTGGTTC  3481 CTCGACAAGC TGGTGGACGA GATCGGTGTG GGTTACGTGC GTGACACTGG CAGCGTCTCC  3541 TGTTACTGTC TGTCCCAGAT CAAGCCTCTG CACAACTTCC TGACCCAGCT CCAGCCCTTC  3601 CTGAAGCTCA AGCAGAAGCA GGCCAACCTC GTGCTGAAGA TCATCGAGCA GCTGCCCTCC  3661 GCCAAGGAAT CCCCGGACAA GTTCCTGGAG GTGTGCACCT GGGTGGACCA GATCGCCGCT  3721 CTGAACGACT CCAAGACCCG CAAGACCACT TCCGAAACCG TCCGCGCCGT TCTAGACAGT  3781 CTCTCCGAGA AGAAGAAGTC GTCCCCCTAA GGTACCAGCG GCCGCTTCGA GCAGACATGA  3841 TAAGATACAT TGATGAGTTT GGACAAACCA CAACTAGAAT GCAGTGAAAA AAATGCTTTA  3901 TTTGTGAAAT TTGTGATGCT ATTGCTTTAT TTGTAACCAT TATAAGCTGC AATAAACAAG  3961 TTAACAACAA CAATTGCATT CATTTTATGT TTCAGGTTCA GGGGGAGATG TGGGAGGTTT  4021 TTTAAAGCAA GTAAAACCTC TACAAATGTG GTAAAATCGA TAAGGATCTA GGAACCCCTA  4081 GTGATGGAGT TGGCCACTCC CTCTCTGCGC GCTCGCTCGC TCACTGAGGC CGCCCGGGCA  4141 AAGCCCGGGC GTCGGGCGAC CTTTGGTCGC CCGGCCTCAG TGAGCGAGCG AGCGCGCAGA  4201 GAGGGAGTGG CCAACCCCCC CCCCCCCCCC CCTGCAGCCT GGCGTAATAG CGAAGAGGCC  4261 CGCACCGATC GCCCTTCCCA ACAGTTGCGT AGCCTGAATG GCGAATGGCG CGACGCGCCC  4321 TGTAGCGGCG CATTAAGCGC GGCGGGTGTG GTGGTTACGC GCAGCGTGAC CGCTACACTT  4381 GCCAGCGCCC TAGCGCCCGC TCCTTTCGCT TTCTTCCCTT CCTTTCTCGC CACGTTCGCC  4441 GGCTTTCCCC GTCAAGCTCT AAATCGGGGG CTCCCTTTAG GGTTCCGATT TAGTGCTTTA  4501 CGGCACCTCG ACCCCAAAAA ACTTGATTAG GGTGATGGTT CACGTAGTGG GCCATCGCCC  4561 TGATAGACGG TTTTTCGCCC TTTGACGTTG GAGTCCACGT TCTTTAATAG TGGACTCTTG  4621 TTCCAAACTG GAACAACACT CAACCCTATC TCGGTCTATT CTTTTGATTT ATAAGGGATT  4681 TTGCCGATTT CGGCCTATTG GTTAAAAAAT GAGCTGATTT AACAAAAATT TAACGCGAAT  4741 TTTAACAAAA TATTAACGTT TACAATTTCC TGATGCGCTA TTTTCTCCTT ACGCATCTGT  4801 GCGGTATTTC ACACCGCATA TGGTGCACTC TCAGTACAAT CTGCTCTGAT GCCGCATAGT  4861 TAAGCCAGCC CCGACACCCG CCAACACCCG CTGACGCGCC CTGACGGGCT TGTCTGCTCC  4921 CGGCATCCGC TTACAGACAA GCTGTGACCG TCTCCGGGAG CTGCATGTGT CAGAGGTTTT  4981 CACCGTCATC ACCGAAACGC GCGAGACGAA AGGGCCTCGT GATACGCCTA TTTTTATAGG  5041 TTAATGTCAT GATAATAATG GTTTCTTAGA CGTCAGGTGG CACTTTTCGG GGAAATGTGC  5101 GCGGAACCCC TATTTGTTTA TTTTTCTAAA TACTTTCAAA TATGTATCCG CTCATGAGAC  5161 AATAACCCTG ATAAATGCTT CAATAATATT GAAAAAGGAA GAGTATGAGT ATTCAACATT  5221 TCCGTGTCGC CCTTATTCCC TTTTTTGCGG CATTTTGCCT TCCTGTTTTT GCTCACCCAG  5281 AAACGCTGGT GAAAGTAAAA GATGCTGAAG ATCAGTTGGG TGCACGAGTG GGTTACATCG  5341 AACTGGATCT CAACAGCGGT AAGATCCTTG AGAGTTTTCG CCCCGAAGAA CGTTTTCCAA  5401 TGATGAGCAC TTTTAAAGTT CTGCTATGTG GCGCGGTATT ATCCCGTATT GACGCCGGGC  5461 AAGAGCAACT CGGTCGCCGC ATACACTATT CTCAGAATGA CTTGGTTGAG TACTCACCAG  5521 TCACAGAAAA GCATCTTACG GATGGCATGA CAGTAAGAGA ATTATGCAGT GCTGCCATAA  5581 CCATGAGTGA TAACACTGCG GCCAACTTAC TTCTGACAAC GATCGGAGGA CCGAAGGAGC  5641 TAACCGCTTT TTTGCACAAC ATGGGGGATC ATGTAACTCG CCTTGATCGT TGGGAACCGG  5701 AGCTGAATGA AGCCATACCA AACGACGAGC GTGACACCAC GATGCCTGTA GCAATGGCAA  5761 CAACGTTGCG CAAACTATTA ACTGGCGAAC TACTTACTCT AGCTTCCCGG CAACAATTAA  5821 TAGACTGGAT GGAGGCGGAT AAAGTTGCAG GACCACTTCT GCGCTCGGCC CTTCCGGCTG  5881 GCTGGTTTAT TGCGGATAAA TCTGGAGCCG GTGAGCGTGG GTCTCGCGGT ATCATTGCAG  5941 CACTGGGGCC AGATGGTAAG CCCTCCCGTA TCGTAGTTAT CTACACGACG GGGAGTCAGG  6001 CAACTATGGA TGAACGAAAT AGACAGATCG CTGAGATAGG TGCCTCACTG ATTAAGCATT  6061 GGTAACTGTC AGACCAAGTT TACTCATATA TACTTTAGAT TGATTTAAAA CTTCATTTTT  6121 AATTTAAAAG GATCTAGGTG AAGATCCTTT TTGATAATCT CATGACCAAA ATCCCTTAAC  6181 GTGAGTTTTC GTTCCACTGA GCGTCAGACC CCGTAGAAAA GATCAAAGGA TCTTCTTGAG  6241 ATCCTTTTTT TCTGCGCGTA ATCTGCTGCT TGCAAACAAA AAAACCACCG CTACCAGCGG  6301 TGGTTTGTTT GCCGGATCAA GAGCTACCAA CTCTTTTTCC GAAGGTAACT GGCTTCAGCA  6361 GAGCGCAGAT ACCAAATACT GTCCTTCTAG TGTAGCCGTA GTTAGGCCAC CACTTCAAGA  6421 ACTCTGTAGC ACCGCCTACA TACCTCGCTC TGCTAATCCT GTTACCAGTG GCTGCTGCCA  6481 GTGGCGATAA GTCGTGTCTT ACCGGGTTGG ACTCAAGACG ATAGTTACCG GATAAGGCGC  6541 AGCGGTCGGG CTGAACGGGG GGTTCGTGCA CACAGCCCAG CTTGGAGCGA ACGACCTACA  6601 CCGAACTGAG ATACCTACAG CGTGAGCATT GAGAAAGCGC CACGCTTCCC GAAGGGAGAA  6661 AGGCGGACAG GTATCCGGTA AGCGGCAGGG TCGGAACAGG AGAGCGCACG AGGGAGCTTC  6721 CAGGGGGAAA CGCCTGGTAT CTTTATAGTC CTGTCGGGTT TCGCCACCTC TGACTTGAGC  6781 GTCGATTTTT GTGATGCTCG TCAGGGGGGC GGAGCCTATG GAAAAACGCC AGCAACGCGG  6841 CCTTTTTACG GTTCCTGGCC TTTTGCTGGC CTTTTGCTCA CATGTTCTTT CCTGCGTTAT  6901 CCCCTGATTC TGTGGATAAC CGTATTACCG CCTTTGAGTG AGCTGATA  SEQ ID NO: 174 (Mouse DMD Intron 22 Forward Primer)     1 CATTTCATATTTAGTGACAT AAGATATGAA GTATG  SEQ ID NO: 175 (Mouse DMD Intron 23 Reverse Primer)     1 GTGTCAGTAA TCTCTATCCC TTTCATG  SEQ ID NO: 176 (Mutant Sequence from Mouse DMD Gene)     1 CATTTCATAT TTAGTGACAT AAGATATGAA GTATGATTAT TCAGCCACTT TATGAACTGC    61 TGGAAGCAAA AATGAGATCT TTGCAACATG AAGCAGTTGC TCAGTTCATT AAACTGTGTT   121 CAATATTTCA GCCATAACAT ACATTAGAGA ATGATTTATA TTGTTCAAAC ATTTGGTGCT   181 CTATTTTTGC ATGACGTGGG ATTAAACACA GCACCAACAA TCAAACAATT GCAAAGATGT   241 ATTACAAGTA TTTTTTCTTT TTAAAACAGG AAAGTATACT TATATTTCCA TTGTCCAAAC   301 CATCATGAAA GGGATAGAGA TTACTGACAC  SEQ ID NO: 177 (Mutant Sequence from Mouse DMD Gene)     1 CATTTCATAT TTAGTGACAT AAGATATGAA GTATGATTAT TAAAATTAAA TCACATTATT    61 TTATTATAAT TACTTTACTC CACAGGTGAT TTCAGCCACT TTATGAACTG CTGGAAGCAA   121 AAATGAGATC TTTGCAACAT GAAGCAGTTG CTCAGTTCAT TAAACTGTGT TCAATATTTC   181 AGCCATAACA TACATTAGAG AATGATTTAT ATTGTTCAAA CATTTGGTGC TCTATTTTTG   241 CATGACGTGG GATTAAACAC AGCACCAACA ATCAAACAAT TGCAAAGATG TATTACAAGT   301 ATTTTTTCTT TTTAAAACAG GAAAGTATAC TTATATTTCC ATTGTCCAAA CCATCATGAA   361 AGGGATAGAG ATTACTGACA C  SEQ ID NO: 178 (Mutant Sequence from Mouse DMD Gene)     1 CATTTCATAT TTAGTGACAT AAGATATGAA GTATGATTAT TAAAATTAAA TCACATTATT    61 TTATTATAAT TACTTTACAC AGGTGATTTC AGCCACTTTA TGAACTGCTG GAAGCAAAAA   121 TGAGATCTTT GCAACATGAA GCAGTTGCTC AGTTCATTAA ACTGTGTTCA ATATTTCAGC   181 CATAACATAC ATTAGAGAAT GATTTATATT GTTCAAACAT TTGGTGCTCT ATTTTTGCAT   241 GACGTGGGAT TAAACACAGC ACCAACAATC AAACAATTGC AAAGATGTAT TACAAGTATT   301 TTTTCTTTTT AAAACAGGAA AGTATACTTA TATTTCCATT GTCCAAACCA TCATGAAAGG   361 GATAGAGATT ACTGACAC