Abstract:
The problem. Ethyl methanesulfonate (EMS) is a potent alkylating agent, capable of inducing mutations in Drosophila at frequencies as great as 70%. EMS is often referred to as a radiomimetic substance because of the similarities between the clinical manifestations of radiation damage and injury due to alkylating agents. Dimethyl sulfoxide (DMSO) provides an effective protection against the mutagenic effects of radiation in many organisms including Drosophila. The major objective of this study was to determine the effects that topical application of DMSO would have on the mutagenic action of ingested EMS.
Procedure. Adult male Drosophila were treated in four ways. The five separate groups tested were treated with DMSO alone, EMS alone, DMSO followed by EMS, and EMS followed by DMSO. The fifth group was a control and received no treatment. Treated adult males were mated individually to three or four virgin Basc females. The Basc technique for detection of X-linked recessive lethal mutations was followed. Mutation frequencies were computed and subsequently submitted to chi square analysis.
Findings. The control group produced a mutation frequency of O.O%. This was used as a spontaneous X-linked recessive lethal mutation rate. The DMSO group demonstrated a 1.3% mutation rate. The EMS group produced a 35.9% mutation frequency. Pre-treatment with DMSO followed by EMS treatment resulted in a mutation rate of 31.6%. DMSO treatment following EMS treatment resulted in a 35.0% mutation frequency.
Conclusions. The data obtained from this study indicates that DMSO does not act as an antimutagenic substance against EMS in Drosophila. DMSO does appear to be slightly mutagenic after topical application and this application seems to reduce the overall reproductive capabilities of the treated males.
Recommendations. Further experimentation with various concentrations of DMSO and different methods of administration is necessary to fully elucidate the actual effects of DMSO in Drosophila.
