[Patterns of transposable elements distribution on the Drosophila melanogaster polytene chromosomes before and after selection for a quantitative trait].

The effect of selection for radius vein length on the distribution of hybridization sites of the P and hobo transposons and the mdgl and mdg2 retrotransposons on polytene chromosomes of Drosophila melanogaster salivary glands was studied. The patterns of these transposable elements (TEs) distribution were polymorphic in both the parental strain and selected strains. The similarity in mdg1 and mdg2 patterns between strains selected in one direction was closer than between strains selected in opposite directions, but the selected strains were closer to each other than to the parental strain regardless of selection direction. No mdg2 hybridization sites that would be absent in the control were found in the selected strains. There were more mdg2 and hobo hybridization sites in the strains selected in the (+) direction than in the (-) direction. The mobility of hobo copies in the strains studied correlated with the presence of its full-sized copy in the genome. The polymorphism of all TEs studied except for mdgl was greater for strains selected in the (+) direction that in the (-) direction. These facts suggest that some TEs migrate over the genome independently of selection, and others are markers of evolutionary events rather than their causes.

[The response of the genomic pattern of transposable elements TE412 to quantitative trait selection in Drosophila melanogaster].

The results of four selection-genetic experiments aimed at the genetic transformation of the quantitative trait controlled by the radius incompletus gene of Drosophila melanogaster are given. Directional (s+) and (s-)-selection was conducted. At the of end all the experiments, in (s+)-selection the radial vein of the wing was restored to the wild phenotype, in (s-)-selection complete elimination of the radial vein took place. In four variants of selection, different TE412 pattern was formed under (s+)-selection and (s-)-selection in final generations. Correlation coefficient between (s+)-selection and (s-)-selection is -0.576, p < 0.001. At the same time, correlation coefficient between two independent replications of (s+)-selection is 0.912, p < 0.001, and of (s-)-selection, 0.946, p < 0.001. Thus, the availability of associated response to the selection of a quantitative trait and to the TE412 pattern is experimentally proved. Three hypotheses of the possible TE behaviour under selection are discussed.