LOCUS ADH OF DROSOPHILA-MELANOGASTER UNDE R SELECTION FOR DELAYED SENESCENCE

Dynamics of the Adh activity and frequencies of alleles Adh(F) and Adh (S) were analyzed under selection for delayed senescence. The experime nts were performed on Drosophila melanogaster. Lines Adh(S)cn and Adh( F)vg and experimental populations cn and vg, selected for an increased duration of reproductive period (late oviposition) were used. Analysi s of fertility, longevity, viability and resistance to starvation show ed that selection for late oviposition resulted in delayed senescence of flies of the experimental populations. Genetic structure of populat ion vg changed considerably with regard to the Adh locus. This was con firmed by parameters of activity, thermostability and electrophoretic mobility of the enzyme isolated from flies after 30 generations of sel ection. Analysis of frequencies of the Adh alleles showed that in both selected populations, which initially had different genetic compositi on, accumulated allele Adh(S), which encodes the isozyme that is less active but more resistant to inactivation. Genetic mechanism of delaye d senescence in Drosophila is assumed to involve selection at vitally important enzyme loci, including Adh.