Excited to share my first first-author paper from my PhD in the @jwmodell lab, out in @CellCellPress today!! Read about how we discovered bacteria evolved their very own CRISPRi sgRNAs to control their native CRISPR-Cas systems, story thread below (authors.elsevier.com/c/1cNb~L7PXcMJ7) Our story starts with a twist! When we performed a transposon screen to search for bacterial regulators of CRISPR immunity, instead of identifying host factors we actually found that disruption of the long isoform of tracrRNA (tracr-L) increased immunity against phage infection!