Disclosed herein are engineered cleavage half-domains; fusion polypeptides comprising these engineered cleavage half-domains; polynucleotides encoding the engineered cleavage half-domains and fusion proteins; and cells comprising said polynucleotides and/or fusion proteins. Also described are methods of using these polypeptides and polynucleotides, for example for targeted cleavage of a genomic sequence.

Many studies have shown that CRISPR-Cas nucleases can tolerate up to five mismatches and still cleave; it is hard to predict the effects of any given single or combination of mismatches on activity. Taken together, these nucleases can show significant off-target effects but it can be challenging to predict these sites. Described herein are methods for increasing the specificity of genome editing using the CRISPR/Cas system, e.g., using RNA-guided FokI Nucleases (RFNs), e.g., FokI-Cas9 or FokI-dCas9-based fusion proteins.

A clustered regularly interspaced short palindromic repeat (CRISPR)-associated complex for adaptive antiviral defence (Cascade); the Cascade protein complex comprising at least CRISPR-associated protein subunits Cas7, Cas5 and Cash which includes at least one subunit with an additional amino acid sequence possessing nucleic acid or chromatin modifying, visualising, transcription activating or transcription repressing activity. The Cascade complex with additional activity is combined with an RNA molecule to produce a ribonucleoprotein complex. The RNA molecule is selected to have substantial complementarity to a target sequence. Targeted ribonucleoproteins can be used as genetic engineering tools for precise cutting of nucleic acids in homologous recombination, non-homologous end joining, gene modification, gene integration, mutation repair or for their visualisation, transcriptional activation or repression. A pair of ribonucleotides fused to FokI dimers may be used to generate double-strand breakages in the DNA to facilitate these applications in a sequence-specific manner.

The invention provides for systems, methods, and compositions for altering expression of target gene sequences and related gene products. Provided are structural information on the Cas protein of the CRISPR-Cas system, use of this information in generating modified components of the CRISPR complex, vectors and vector systems which encode one or more components or modified components of a CRISPR complex, as well as methods for the design and use of such vectors and components. Also provided are methods of directing CRISPR complex formation in eukaryotic cells and methods for utilizing the CRISPR-Cas system. In particular the present invention comprehends optimized functional CRISPR-Cas enzyme systems, wherein the guide sequence is modified by secondary structure to increase the specificity of the CRISPR-Cas system and whereby the secondary structure can protect against exonuclease activity and allow for 5 additions to the guide sequence.

Disclosed herein are methods and compositions for targeted cleavage of a genomic sequence, targeted alteration of a genomic sequence, and targeted recombination between a genomic region and an exogenous polynucleotide homologous to the genomic region. The compositions include fusion proteins comprising a cleavage domain (or cleavage half-domain) and an engineered zinc finger domain and polynucleotides encoding same. Methods for targeted cleavage include introduction of such fusion proteins, or polynucleotides encoding same, into a cell. Methods for targeted recombination additionally include introduction of an exogenous polynucleotide homologous to a genomic region into cells comprising the disclosed fusion proteins.

The present invention provides RNA-guided endonucleases, which are engineered for expression in eukaryotic cells or embryos, and methods of using the RNA-guided endonuclease for targeted genome modification in eukaryotic cells or embryos. Also provided are fusion proteins, wherein each fusion protein comprises a CRISPR/Cas-like protein or fragment thereof and an effector domain. The effector domain can be a cleavage domain, an epigenetic modification domain, a transcriptional activation domain, or a transcriptional repressor domain. Also provided are methods for using the fusion proteins to modify a chromosomal sequence or regulate expression of a chromosomal sequence.

Disclosed herein are engineered cleavage half-domains; fusion polypeptides comprising these engineered cleavage half-domains; polynucleotides encoding the engineered cleavage half-domains and fusion proteins; and cells comprising said polynucleotides and/or fusion proteins. Also described are methods of using these polypeptides and polynucleotides, for example for targeted cleavage of a genomic sequence.

A method of diagnosing a disease associated with a DNA repeat sequence is disclosed. The method comprises: (a) determining the number of repeats of a DNA sequence in DNA molecules of a sample of the subject; and (b) determining the CpG methylation status of the DNA molecules, wherein the number of repeats of the DNA sequence and the CpG methylation status of the DNA molecules is indicative of the disease.

Materials and methods related to gene targeting (e.g., gene targeting with transcription activator-like effector nucleases; TALENS) are provided.

The present invention relates in part to nucleic acids encoding proteins, therapeutics comprising nucleic acids encoding proteins, methods for inducing cells to express proteins using nucleic acids, methods, kits and devices for transfecting, gene editing, and reprogramming cells, and cells, organisms, and therapeutics produced using these methods, kits, and devices. Methods and products for altering the DNA sequence of a cell are described, as are methods and products for inducing cells to express proteins using synthetic RNA molecules. Therapeutics comprising nucleic acids encoding gene-editing proteins are also described.