[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. The total frequency of DLM realized at all developmental stages correlated with that of DLM realized at the embryonic stages and was determined by the maternal organism. The maternal effect in the determination of DLM frequency was not related to the shift in the stage of their realization. The DLM frequency at the embryonic stage may serve as a criterion of mutational process in strains since it reflects their genetical structure but its utilization for characterization of hybrid combinations is not expedient as it is mainly determined by the maternal organism.