AN IMPROVED SECOND CHROMOSOME BALANCER IN DROSOPHILA MELANOGASTER

Abstract

Dominant temperature sensitive lethals (DTSLs) and semilethals were induced by EMS on the SM5 balancer of Drosophila melanogaster at the rate of 0.0025. SM5 DTSL4 is a fully penetrant line with 1000% lethality at the nonpermissive temperature of 2S°C. At the permissive temperature (l9°C) it shows normal fertility and survival. DTSL4 is basically a pupal lethal but exerts strong paternal influence over embryonic and larval development. DTSL4 does not alter the recombination suppression properties of SM5. Individuals homozygous for second chromosome loci can now be generated with ease from SM5 DTSL4/+ parents at 2S°C.