ETHANOL AND ACETIC-ACID TOLERANCES IN DROSOPHILA-MELANOGASTER - SIMILAR MATERNAL EFFECTS IN A CROSS BETWEEN 2 GEOGRAPHIC RACES

Ethanol and acetic-acid tolerances were studied in a cross between 2 g eographic races of Drosophila melanogaster, ie a very sensitive popula tion from equatorial Africa and a resistant French population. Average values in the F1 and F2 were similar and close to the mid-parent valu e. A clear maternal genotype effect was, however, observed for both tr aits between reciprocal F1s, and the difference disappeared in the F2. Further investigations demonstrated that for ethanol tolerance, the l arge difference between the parental strains was not entirely due to d ifferences in their allelic frequencies at the Adh locus. The possible mechanisms of these physiological variations are discussed.