Induced Changes in Female Germ Cells of Drosophila. VI. the Effect of Dehydration upon the X-Ray-Induced Frequencies of Crossover-like Exchanges and of Gross Chromosomal Rearrangements.

EHYDRATION of Drosophila melanogaster virgin females before irradiaD tion increases the frequency of mortality for eggs laid approximately the first eight days after mating (HERSKOWITZ 1957). No decision was reached from this work as to whether or not the dehydration-increased egg mortality had a genetic basis. The present experiments aimed to test whether X-ray-induced frequencies of gross chromosomal rearrangements and of crossover-like exchanges are modified by maternal dehydration prior to irradiation. The findings are discussed in relation to those from the earlier study on dehydrationdependent egg mortality. Part of these results have been summarized elsewhere (HERSKOWITZ 1956).