The presently disclosed subject matter provides compositions and methods for the expression of CRISPR guide RNAs using the H1 promoter. In particular, compositions and methods are provided for the use of the H1 promoter to express CRISPR guide RNA (gRNA) with altered specificity of the 5 nucleotide, as well as use of the H1 promoter sequence as a bidirectional promoter to express Cas9 nuclease and the gRNA simultaneously. Compositions and methods are also provided for the expression and regulation of gRNA expression in vivo through the use of RNA ribozymes and regulatable aptazymes.

The present disclosure relates to viral delivery of RNA utilizing self-cleaving ribozymes and applications of such, including but not limited to CRISPR-Cas related applications.

Described herein are methods for treating a retinal degeneration in a subject, such as Leber's congenital amaurosis (LCA), retinitis pigmentosa (RP), and glaucoma. Also provided herein are methods of altering expression of one or more gene products in a cell, such as a retinal ganglion cell. Such methods may comprise utilizing a modified nuclease system, such as Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) system comprising a bidirectional HI promoter and gRNAs directed to retinal degeneration related genes, packaged in a single, compact adeno-associated virus (AAV) particle.

Provided are constructs and methods for RNA promoter identification.

The invention provides polynucleotide constructs for the regulation of gene expression by aptamer-based modulation of self-cleaving ribozymes and methods of using the constructs to regulate gene expression in response to the presence or absence of a ligand that binds the aptamer. The invention further provides methods for making and using riboswitches that decrease target gene expression in response to an aptamer ligand as well as riboswitches that increase target gene expression in response to an aptamer ligand.

A ligand-responsive hammerhead ribozyme is provided. In some embodiments, the ribozyme comprises: i. a first loop that has been replaced by an RNA aptamer that binds to a ligand; and ii. a second loop comprising a modified sequence, wherein the aptamer and the second loop interact in a ligand-dependent manner and autocatalytic cleavage of the ribozyme is ligand-responsive.

Non-conventional yeasts are disclosed herein comprising at least one RNA-guided endonuclease (RGEN) comprising at least one RNA component that does not have a 5-cap. This uncapped RNA component comprises a sequence complementary to a target site sequence in a chromosome or episome in the yeast. The RGEN can bind to, and optionally cleave, one or both DNA strands at the target site sequence. An example of an RGEN herein is a complex of a Cas9 protein with a guide RNA. A ribozyme is used in certain embodiments to provide an RNA component lacking a 5-cap. Further disclosed are methods of genetic targeting in non-conventional yeast.

The present disclosure provides CRISPR-Cas effector polypeptides that exhibit enhanced gene editing and/or trans cleavage activity, compared to a wild-type CasPhi polypeptide. The present disclosure provides systems and kits comprising such CRISPR-Cas effector polypeptides. The present disclosure provides methods, including gene editing and diagnostic methods, using a CRISPR-Cas effector polypeptide of the present disclosure.

The presently disclosed subject matter provides compositions and methods for the expression of CRISPR guide RNAs using the H1 promoter. In particular, compositions and methods are provided for the use of the H1 promoter to express CRISPR guide RNA (gRNA) with altered specificity of the 5 nucleotide, as well as use of the H1 promoter sequence as a bidirectional promoter to express Cas9 nuclease and the gRNA simultaneously. Compositions and methods are also provided for the expression and regulation of gRNA expression in vivo through the use of RNA ribozymes and regulatable aptazymes.

The presently disclosed subject matter provides compositions and methods for the expression of CRISPR guide RNAs using the H1 promoter. In particular, compositions and methods are provided for the use of the H1 promoter to express CRISPR guide RNA (gRNA) with altered specificity of the 5 nucleotide, as well as use of the H1 promoter sequence as a bidirectional promoter to express Cas9 nuclease and the gRNA simultaneously. Compositions and methods are also provided for the expression and regulation of gRNA expression in vivo through the use of RNA ribozymes and regulatable aptazymes.