TERATOGENIC EFFECTS OF MILD HEAT-TREATMENT ON DROSOPHILA-MELANOGASTER

This report emphasize the influence of minor thermal environmental changes over Drosophila development and attention at cellular for those drastic effects induced by apparently negligible external agents. Drosophila melanogaster female flies transferred from 26 degrees C to 31 degrees C and maintained for several time intervals at 31 degrees C (from 24 hours ta 96 hours) suffered great changes in ovoposition and eggs viability. Layered eggs from these flies presented a great percentage of abortion and the remaining viable population displayed several morphogenetic abnormalities. Ovoposition failure embryos abortive development and morphogenetic abnormalities are proportional to the maintenance time of parental flies at 31 degrees C. Some morphogenetic abnormalities have a phenocopy character. chiefly Notch phenotype. The target organs for 31 degrees C action are the ovaries. There is no direct male contribution to those effects. The great majority (80-90%) of eggs derived from long term (72 hours) treated females has its development arrested a the pre-blastoderm phase. Electrophoretic and auto-radiographic analysis of in vivo and in vitro thermally treated ovaries revealed alterations in the de novo protein synthesis.