PMC:4502371 / 6760-8371 JSONTXT

{"project":"2_test","denotations":[{"id":"25917920-11381264-43299621","span":{"begin":997,"end":1001},"obj":"11381264"},{"id":"25917920-16156901-43299622","span":{"begin":1016,"end":1020},"obj":"16156901"}],"text":"SNP mapping:\nThe death phenotype during the L4 molt was called drop-dead, Drd. To identify the chromosome on which the drd mutation resides, the mutant was crossed to four mutants: unc-29 I, unc-119 III, dpy-20 IV, and unc-51 V. F2s homozygous for the marker from each cross produced approximately 20% Drd except the cross to unc-119 (\u003c3%). This mapped drd to chromosome III. Mating unc-119(ed3) with Drd homozygotes yielded wild-type F1 progeny, indicating the mutation is recessive. Thirteen out of 14 F2 Unc produced no Drd progeny (F3), validating that drd is linked to unc-119 on chromosome III. One Unc produced progeny with both Unc and Drd phenotypes by recombination. This unc-119(ed3) drd (uy19) grows normally at 15°. We used it for further SNP mapping. The unc-119(ed3) drd (uy19) double mutants mated with Hawaiian CB4856 males produced wild-type progeny (F1). We placed 48 F2 Unc singly onto plates, and then the DNA of F3 progeny was collected for further SNP mapping (Wicks et al. 2001; Davis et al. 2005). Because unc-119 is located at 10.9 Mb, SNP markers on ZK1236 (8.4 Mb), C07A9 (9.6 Mb), T21C12 (10.5 Mb), Y39A1A (10.6 Mb), and Y75B8A (12.0 Mb) were selected. One hundred percent (44/44) of Unc progeny carried only the N2 marker (0% Hawaiian) at 12.0 Mb, suggesting that the mutation is located to the left of unc-119. Forty-eight percent (21/44) of Unc progeny carried only the N2 marker at T21C12 (10.5 Mb) and 58% (26/45) of Unc progeny carried only the N2 marker at Y39A1A (10.6 Mb). Based on the recombination frequencies, we estimated the drd location at approximately 10.1–10.2 Mb."}