meIs8 [pie-1p::GFP::cosa-1 + unc-119(+)] II. Transgene contains a combination of cDNA and genomic sequences of cosa-1 including 212 bp of 3'UTR. GFP is expressed in the adult germline as 6 bright foci per nucleus (one per chromosome pair) from late pachytene through diplotene stages. Homozygous sterile mutation balanced by GFP- and dpy-10-marked inversion. Heterozygotes are WT with relatively dim pharyngeal GFP signal, and segregate WT dim GFP, Dpy bright GFP (mIn1 homozygotes), and non-GFP me103 homozygotes (sterile adult). Pick WT dim GFP and check for correct segregation of progeny to maintain. nbs-1(me103) homozygotes have frayed and aggregated chromosomes at diakinesis of meiosis I. References: Girard C, et al. Proc Natl Acad Sci U S A. 2018 May 8;115(19):E4443-E4452. Yokoo R, et al. Cell. 2012 Mar 30;149(1):75-87.