INHERITANCE OF ETHER RESISTANCE IN DROSOPHILA MELANOGASTER

Abstract

An ether resistant female fly appeared from a radioresistant Mino-H strain, and the offspring of this fly was selected for resistance successively by deep etherization. It was found that the selection pressure was effective. The ether resistant strains which have been selected for 13 generations and 28 generations are called Eth-13 and Eth-28 strains respectively. Quick Sand wild-type strain is susceptible as are also two mutant strains, bar-3 ca and bw; st; svⁿ. In general, the females are more resistant than the males in each strain. Reciprocal crosses showed that resistance to etherization was completely dominant over sensitivity and that maternal or cytoplasmic effects were negligible. The third chromosome is mainly responsible for ether resistance, and the locus of the major gene(s) for ether resistance may be around 61±, and minor genes are also found on the X-chromosome and on the fourth chromosome. We assume that the major genes for resistances to nicotine sulfate, to etherization and to radiation are different from each other at the present status of our experiments.