[Mechanisms ensuring the resistance of the genetic material of the cell to stress exposures].

A brief review of studies performed in the Department of Genetics of St. Petersburg University by M.E.

[Analysis of the frequency of spontaneous and induced autosomal recessive lethal mutations in the oogenesis of the radiosensitive mutant rad(2)201G1 of Drosophila melanogaster].

The frequency of spontaneous and gamma-ray induced autosomal recessive lethals has been studied in chromosomes 2 and 3 at different stages of Drosophila melanogaster radiosensitive mutant rad (2) 201G1 oogenesis. The frequency of spontaneous lethals in radiosensitive mutant was higher by the order of magnitude as compared with wild-type flies (9.3 and 0.

[Radiosensitivity of somatic cells and imaginal disks of male and female Drosohila].

Primary chromosome damages as well as the frequency of spontaneous and X-rays induced chromosome aberrations in Drosophila melanogaster males and females are studied. It is found using cytofluorimetric method that primary chromosome damages in ganglia cells of females and males are the same. In these cells as well as in cells of imaginal discs the frequency of induced chromosome aberrations, except gaps, is considerably higher for females.

[The dynamics of realization of spontaneous dominant lethal mutations during drosophila ontogenesis].

The dynamics of realization of spontaneous dominant lethal mutations (DLM) has been studied in cyclic crosses of 5 strains of Drosophila at 3 developmental stages. The frequency of the DLM realized at the embryonic stage was shown to be determined by the maternal organism. No predominant role of either parent in the realization of DLM at the larval and pupal stages was established.