Development of tolerance to ethanol in relation to the alcohol dehydrogenase locus in Drosophila melanogaster 1. Adult and egg-to-adult survival in relation to ADH activity

Abstract

Strains of Drosophila melanogaster homozygous either for the AdhF or the Adhs allele, were kept on food supplemented with ethanol. After 90 generations these strains (FFE and SSE) were tested for tolerance to ethanol and compared with control strains (FFN and SSN) from regular food. The E strains showed increased tolerance to ethanol, both in the adult and in the juvenile life stages. In the adults the increase in tolerance was not accompanied by an increase in ADH activity. In the juvenile life stages there were significant differences in ADH activity between the E and N strains, both on regular food and on food containing ethanol. However, ADH activity was not the only factor involved in the increased tolerance to ethanol.The Adh genotype of the mother was of paramount importance to egg-to-adult survival because of a maternal effect on ethanol tolerance in the eggs and first instar larvae. Furthermore developmental times of the E strains were longer than those of the corresponding N strains. It is concluded that the adaptation to ethanol-containing food was not realised in the same way in the FFE and SSE strains.

Polymorphism at the Adh and αGpdh loci in Drosophila melanogaster: effects of rearing temperature on developmental rate, body weight, and some biochemical parameters

“…Literature on the developmental rate of Adh genotypes comes from (i) selection experiments for developmental rate in polymorphic populations (Van Delden & Kamping, 1979;Cavener, 1983;, (ii) determination of genotype frequencies in fast and slow developing groups within polymorphic populations (Van Delden & Kamping, 1979;Marinkovié et. al., 1987), and (iii) measurement of developmental rate of homozygous strains (Kerver & Van Delden, 1985;Kohane & Parsons, 1986;Lzquierdo & Rubio, 1989). Although some of these studies revealed no differences in the rate of development between Adh genotypes, most studies indicated that AdhFF develops faster than in agreement with these findings.…”

Regulatory differences in developmental expression of alcohol dehydrogenase are related to interspecies differences in ethanol tolerance of Drosophila

“…In general, ethanol as a selective agent can act either at the preadult or adult stages of Drosophila. It was shown earlier that in D. melanogaster, the adaptation to ethanol-rich media was mainly accomplished during the juvenile life stages and that the maternal ADH has a significant role in that process (Kerver & van Delden, 1985;Kerver & Rotman, 1987). In the virilis phylad of Drosophila, ADH is not maternally encoded and zygotic transcription of Adh is not seen until the 24th hour of embryogenesis (G. Ranganayakulu, unpublished data).…”

Selection against Adh null alleles in Drosophila melanogaster

“…Methanol is a toxic alcohol to D. melanogaster (though it is not a substrate of ADH). Although methanol is not converted by ADH, the Ad/iF frequency Selection for an independent resistance to methanol (Van Delden and Kamping, 1983;Kerver and Van Delden, 1985) may have occurred, diminishing the fitness differences between Ad/i genotypes. Viability estimates for 0/0 and 0/ + on methanol (0.76 and 092 respectively) are lower than those for normal food (0.88 and 095 respectively) and indicate that these genotypes experience an initially greater disadvantage relative to +/+ than on normal food.…”