EMS and x-ray induced mutability in the vermilion region of the X chromosome of Drosophila melanogaster

A study was made of EMS and X--ray--induced mutations occurring in the immediate vicinity of the vermilion (v, 1-33, 0) locus. This region of the X chromosome was covered by a special Y chromosome containing a duplication extending from salivary chromosome band 9F5 through 10C2, which should permit the recovery of female-sterile or sex determining mutants in this region. Approximately 6000 F1 males were examined and over 2500 chromosomes tested for the presence of male-lethal and female-sterile mutations; no female-sterile mutants were found. Fourteen recessive lethal mutants were induced, of which 3 were in the covered region. Ten viable and fertile visible mutants, including a lozenge (lz, 1-27. 7), a furrowed (fw, -1-36.8), a white (w, 1-1. 5), and a garnet (g, 1-44, 4). The most interesting mutant found was a male -viable v mutant accompanied by a simultaneously induced, independent semi -lethal mutant located approximately 0.6 crossover units to the right of v.