[Recombination in Drosophila in space flight]. / Rekombinatsiia u drozofily v usloviiakh kosmicheskogo poleta.

An experiment with Drosophila melanogaster males was performed aboard the Artificial Satellite "Kosmos-1667". Mutagenic effects of a 7-day space flight on intergene recombination in chromosome 2 were studied. The space flight factors decreased the frequency of recombination. A model experiment on a laboratory centrifuge demonstrated insignificant increase in recombination frequency caused by acceleration.

[Frequency of chromosome recombination, nondisjunction and breaks in Drosophila melanogaster males exposed during space flight]. / Chastota rekombinatsii, neraskhozhdeniia i razryvov khromosom u samtsov Drosophila melanogaster, éksponirovannykh v orbital'nom polete.

Effects of space flight factors on chromosomal nondisjunctions, breaks and mitotic recombination in Drosophila melanogaster males were studied. It was shown that space flight conditions increased the frequencies of nondisjunctions, breaks and mitotic recombination in chromosomes. It was established that the vibration and acceleration effects could not serve to explain the data obtained. On the basis of these data, it may be suggested that weightlessness and cosmic radiation are the main factors which are responsible for the effects observed.

[Effect of the dynamic factors of space flight on the mutagenic effect of radiation. II. Development of recessive lethals and loss of X-chromosomes in Drosophila melanogaster oocytes]. / Vliianie dinamicheskikh faktorov kosmicheskogo poleta na mutagennyi éffekt radiatsii. Soobshchenie II. Vozniknovenie retsessivnye letalei i poter' X-khromosom v ootsitakh Drosophila melanogaster.

The modifying effect of dynamic space-flight factors on radiation damage of Drosophila oocytes was measured by the frequencies of X-chromosomal non-disjunction, loss and sex-linked recessive lethals. It has been shown that with a slight increase in the non-disjunction frequency, dynamic factors did not influence the frequency of loss events in irradiated oocytes. The yield of recessive lethal mutations increased in irradiated oocytes-7 both upon pre- and postradiation action of dynamic factors. A similar increase in the frequency of recessive lethals was observed after an additional action of acceleration on irradiated oocytes. It is assumed that the modifying effect of dynamic factors is associated with repair repression at early stages of radiation damage.

[Genetic effects in Drosophila caused by space flight factors in "Kosmos-573"]. / Geneticheskie éffekty u drozofily, vyzvannye faktorami kosmicheskogo poleta na "Kosmose-573"

It was proved in the experiments conducted on the space-ship "Cosmos 573" that the factors of the cosmic flight raised significantly the mutability in the D-32 wild type line of Drosophila melanogaster for two kinds of mutations: sex-linked recessive lethals and visible mutations in two X-chromosome's locuses: white and yellow.