[Effect of parental age on endoreduplication of giant chromosomes and some quantitative traits in Drosophila melanogaster descendants]. / Vliianie vozrasta roditelei na funktsiiu éndoreduplikatsii gigantskikh khromosom i nekotorye kolichestvennye priznaki u potomkov Drosophila melanogaster.

We studied the influence of parental age on the degree of polyteny of giant chromosomes and expressivity of mutation eyeless in Drosophila melanogaster descendants. The parental age equal to six days exerted an adverse effect on the function of endoreduplication of giant chromosomes in strain eyeless. The highest degree of polyteny was observed in descendants of four- and ten-day imago. The maximum reduction of eye facets was observed in descendants of four-day imago, while in the progeny of older parents, the mutation expressivity was sharply reduced. Relations between the changes in chromosome polyteny, expressivity of mutation eyeless, and earlier studied components of adaptation were statistically analyzed in descendants of aging parents of this Drosophila strain.

[Effect of culture density and degree of expression of the trait "eyeless" and degree of polyteny of giant chromosomes in Drosophila melanogaster]. / Vliianie plotnosti kul'tury na ékspessivnost' priznaka "eyeless" i stepen' politenii gigantskikh khromosom u Drosophila melanogaster.

Effects of culture density on expressivity of character eyeless and polyteny of giant chromosomes were studied in Drosophila melanogaster. Larval crowding was shown to significantly reduce eye facets. The expression of eyeless was sex-dependent: in females, this character was expressed more strongly than in males. Larval crowding resulted in a decrease of chromosome polyteny in larval salivary glands. A strong negative correlation was established between the expressivity of eyeless and the degree of giant chromosome polyteny.

[Dynamics of changes in various adaptation components in Drosophila ontogenesis]. / Dinamika izmeneniia nekotorykh komponentov prisposoblennosti v ontogeneze drosofily.

We studied the effect of parental age on expressivity of trait eyeless, fertility, heat resistance, and life span of Drosophila offspring. We found that these characteristics show different changes in the offspring of aging parents. The ontogenetic curve of changes of expressivity of the trait eyeless and fertility is similar to the curve of normal distribution. As concerns the changes in heat resistance, they are complex in nature: the offspring of "young" or "old" parents has the highest heat resistance. Age of parents in the studied range does not significantly affect the mean life span of the offspring.