Reduced Cas9 transgene silencing by incorporation of intron sequences.

ABSTRACT: Silencing remains a significant challenge for exogenous gene expression, limiting both the penetrance and expressivity of transgenes. In particular, silencing of Cas9 expression is a major technical limitation for many gene editing and CRISPR screening applications. Here, we demonstrate that including introns in Cas9 expression cassettes significantly reduces silencing across multiple cell lines. Notably, the incorporation of an intron into a CRISPRa construct results in reduced silencing, increased expression levels, and markedly enhanced activation of target genes. We investigate diverse intron sequences and discover that T-rich introns over 2 kb confer the greatest protection against silencing. In addition, we find that introns can work synergistically with chromatin opening elements to

SUBMITTER: Arana S 

PROVIDER: S-EPMC12660324 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature