Abstract
The role of high temperature resistance in the world-wide cline of Adh and alpha Gpdh allele frequencies of Drosophila melanogaster was investigated. Experimental strains were used with different combinations of Adh and alpha Gpdh alleles but with similar genetic background. The survival time of adult males, reared at different pre-adult temperatures, was measured at 35 degrees C. To investigate the relationship between survival and protein content, triglycerides content and ADH and alpha GPDH enzyme activity, the latter characters were measured before and after 12 h exposure to 35 degrees C. Three-way ANOVA of survival at 35 degrees C showed significant effects of rearing temperature and Adh genotype, interaction between Adh and alpha Gpdh, interaction between Adh and rearing temperature and interaction between Adh, alpha Gpdh and rearing temperature, alpha GPDH enzyme activity did not change significantly. Although protein content, triglycerides content and ADH enzyme activity decreased significantly at 35 degrees C, no correlation was observed between survival and these traits. It is concluded that the world-wide cline of Adh and alpha Gpdh allele frequencies cannot simply be explained by the genotypic differences in resistance to high temperature of adult Drosophila melanogaster.
