Using the white gene as an indicator of CRISPR-based editing

Ge DT, Tipping C, Brodsky MH, Zamore PD. Rapid Screening for CRISPR-Directed Editing of the Drosophila Genome Using white Co-Conversion. G3 (Bethesda). 2016 Aug 19. pii: g3.116.032557. PMID: 27543296.

From the abstract: "... Here, we describe a strategy that reduces the time and effort required to identify flies with targeted genomic changes. The strategy uses editing of the white gene, evidenced by altered eye color, to predict successful editing of an unrelated gene-of-interest. The red eyes of wild-type flies are readily distinguished from white-eyed (end joining-mediated loss of White function) or brown-eyed (recombination-mediated conversion to the whitecoffee allele) mutant flies. ... We find that end joining-mediated mutations often show signatures of microhomology-mediated repair and that recombination-based mutations frequently involve donor plasmid integration at the target locus. Finally, we show that gap repair induced by two guide RNAs more reliably converts the intervening target sequence, whereas the use of Lig4169 mutants to suppress end joining does not improve recombination efficacy."