Embryonic and post-embryonic lethals induced by diethyl sulfate in mature sperm of Drosophila melanogaster

Abstract

It has recently been reported that, in Drosophila melanogaster, when sperm treated with diethyl sulfate was stored in the females, II–III translocations were detected as from the 6th day after the treatment, though none was recovered without storage. Chromosome breaks being currently considered the main cause of dominant lethality and the embryonic period lasting about one day at 25°C, it was thought of interest to study the ability of DES to induce this type of damage with and without storage. It was found that the treatment increased embryonic lethality (measured as frequency of unhatched eggs) and post-embryonic lethality (measured as frequency of larval and pupal death) over the control values. The frequency of embryonic lethals after storage in the females for 6 days was similar to that shown by the unstored samples. In contrast with this, the yield of post-embryonic lethality was markedly raised by that storage time. It is suggested that: (1) lesions are induced as “pre-breaks”, and storage and cell divisions are instrumental in their opening; (2) potential breaks can undergo DNA replication and cell division as such and become open in different cell cycles, impairing embryonic and post-embryonic development; (3) chromosome breaks induced by DES seem to behave in a way similar to those induced by other mono- and poly-functional alkylating agents; and (4) when the potential ability of chemical compounds to induce chromosome breaks is assessed, post-embryonic lethality can be used as a simple one-generation preliminary test, to establish delayed effects.