Tests for Chemical Mutagens in Drosophila Using the Vaginal Douche Technic. * †

Abstract

Summary

Vaginal douches of 4% methyl bis (β-chloroechyl) amine hydrochloride produced 53 lethals in 5488 egg and sperm X chromosomes tested while only 13 lethals were observed in the 6271 sperm or egg X chromosomes tested after treatments with formaldehyde, copper sulfate, 2,4-dinitrophenol, hydrazine hydrate and trypsin. The practicality of the vaginal douche technic for the induction of mutations with N mustard in both sperm and eggs, suggested from previous experiments, is confirmed in that 30 lethals occurred in the 2951 sperm tested and 23 in the 2537 eggs tested. The number of sperm X chromosome lethals seems to be considerably higher in F₁ females resulting from single copulations within a two hour period from the time of injection (23 lethals in 1416 tests) than it is in females from copulations after this interval (7 lethals in 1535 tests); the mutation rate for the egg X chromosome under these conditions remains apparently unaffected (9/1083 and 14/1454, respectively). Whereas the 30 sperm lethals seem to be distributed at random among the F₁ females oviposited at various times, the frequency of egg lethals in individuals oviposited during the first two days (18/649) is statistically larger than the frequency of lethals in F₁ females coming from eggs deposited after that time (5/1888).

The use and effects of vaginal douche treatments are discussed and results of the experiments evaluated in the light of studies of other workers testing these chemicals in Drosophila.