antIs31 [attP-f + Cbr-unc-119(ant40) + glh-2p::phiC31 + rol-6(partial) + myo-2p::GFP + attP-r] II. Unc. antIS31 has been found to self-excise; check for GFP expression periodically to retain the insertion. GFP expression in pharynx is very weak (as it is in single copy) and is easiest to see during the L1-L3 stages. This strain contains a phiC31 docking site and can be used for precise single-copy integration of transgenes via recombination mediated cassette exchange. The docking site contains inverted phiC31-attP sites flanking phiC31 integrase expressed from the glh-2 germline promoter. Integration constructs need to have inverted phiC31-attB sites that flank the intended sequence to be inserted. antIs31 was derived by CRISPR/Cas9 knockout of Cbr-unc-119 in antIs30 creating ant40, a 691 bp deletion in Cbr-unc-119. Because antIs31 does not rescue unc-119(ed3), BRC566 facilitates the use of Unc-119 rescue as a selection marker for transgene insertions. Reference: Yang FJ, et al. "phiC31 integrase for recombination mediated single copy insertion and genome manipulation in C. elegans." Genetics 2021.