The present invention relates to systems and methods for recording and assaying cellular events, in particular gene expression. The invention provides hereto a method of determining a cellular event of interest in a cell comprising providing a cell comprising a CRISPR-Cas system, wherein the CRISPR-Cas system comprises a guide RNA that targets a selected DNA sequence and a Cas protein capable of modifying the selected DNA sequence; whereby a nucleic acid molecule encoding at least one of the guide RNA or Cas protein is operably connected in the cell with a regulatory element comprising a promoter responsive to the cellular event, and whereby expression of at least one CRISPR-Cas system component is driven by the promoter; and determining cellular event of interest based on detection of the modification of the selected DNA sequence.

The present invention provides methods and compositions for reducing lactate production and increasing polypeptide production in cultured cells. In one aspect, the invention provides a method comprising culturing cells expressing a) a small interfering RNA (siRNA) specific for a lactate dehydrogenase (LDH) and b) an siRNA specific for a pyruvate dehydrogenase kinase (PDHK). In another aspect, the invention provides cultured cells or vectors comprising an siRNA specific for a LDH and an siRNA specific for a PDHK.

Provided herein are methods and compositions for modulating gene expression in insects by administering a composition comprising an RNA effector molecule and a delivery agent. Methods are provided for controlling pest populations by inhibiting insect growth, development, survival, reproduction and/or viability. Also provided herein are methods for treating or preventing disease in an insect caused by a pathogen or by external factors (e.g., pollution, environment, stress, weather, etc.).

Aspects of the disclosure relate to particle formulations, e.g., nanoparticle formulations, methods of making particle formulations, and methods for delivery of oligonucleotides and/or synthetic RNA, e.g., for increasing gene expression in a targeted manner. In some embodiments, compositions and methods are provided that are useful for posttranscriptionally altering protein and/or RNA levels in a targeted manner. Aspects of the disclosure described herein provide compositions and methods that are useful for protecting RNAs from degradation (e.g., exonuclease mediated degradation).

Isolation or in vitro assembly of the Cas9-crRNA complex of the Streptococcus thermophilus CRISPR3/Cas system and use for cleavage of DNA bearing a nucleotide sequence complementary to the crRNA and a proto-spacer adjacent motif. Methods for site-specific modification of a target DNA molecule in vitro or in vivo using an RNA-guided DNA endonuclease comprising RNA sequences and at least one of an RuvC active site motif and an HNH active site motif; for conversion of Cas9 polypeptide into a nickase cleaving one strand of double-stranded DNA by inactivating one of the active sites (RuvC or HNH) in the polypeptide by at least one point mutation; for assembly of active polypeptide-polyribonucleotides complex in vivo or in vitro; and for re-programming a Cas9-crRNA complex specificity in vitro and using a cassette containing a single repeat-spacer-repeat unit.

The present invention provides methods and compositions for reducing lactate production and increasing polypeptide production in cultured cells. In one aspect, the invention provides a method comprising culturing cells expressing a) a small interfering RNA (siRNA) specific for a lactate dehydrogenase (LDH) and b) an siRNA specific for a pyruvate dehydrogenase kinase (PDHK). In another aspect, the invention provides cultured cells or vectors comprising an siRNA specific for a LDH and an siRNA specific for a PDHK.

A gene vector adapted for transient expression of a transgene in a peripheral organ cell comprising a regulatory sequence operably linked to a transgene wherein the regulatory sequence prevents or reduces expression of said transgene in hematopoietic lineage cells.

Some embodiments relate to methods for the recombinant expression of a protein of interest in a mammalian host cell, use of an shRNA or an siRNA directed against the Galectin-1 gene for increasing the expression of a protein of interest in a mammalian host cell and kits comprising an shRNA or an siRNA and a CHO cell.

The present invention provides donor polynucleotides formed by linking the two ends of a genomic fragment containing a cleavable site by a polynucleotide carrying a positive selection marker gene and a negative selection marker gene. Use of the donor polynucleotide makes it possible to modify only a target gene with avoiding the possibility of introducing mutations to sequences, called off-target, which are other than the target sequence, by introducing cleavage in a homologous site of the donor polynucleotide without introducing cleavage in a target gene locus.

Provided herein are methods and compositions for modulating gene expression in insects by administering a composition comprising an RNA effector molecule and a delivery agent. Methods are provided for controlling pest populations by inhibiting insect growth, development, survival, reproduction and/or viability. Also provided herein are methods for treating or preventing disease in an insect caused by a pathogen or by external factors (e.g., pollution, environment, stress, weather, etc.).