[Comparative contribution of different genetic factors in induction of MGE transpositions under isogenization]

Localization patterns of mobile genetic element 412 in polytene chromosomes of larvae from the control (riC) line, the balancer line, the F1 and F2 generations of the isogenization scheme, and 10 final isogenic lines were obtained and compared. The contributions of the recombination transfer of mobile genetic element copies from the balancer line, the outbreeding of control and balancer lines, and the inbreeding of isogenized lines to the rate of transposition were determined and estimated. These constituted < 0.187, < 0.30, and > 0.207 events per initial mobile genetic element copy per isogenized haploid genome per isogenization, respectively. During consecutive steps of isogenization (F1-F2-isogenic lines), the total transposition rate decreased: 2.09, 1.78, and 0.69. This was explained in terms of the existence of large selective and random losses in the variability of mobile genetic elements within the sites of their patterns during isogenization. The existence of a recombination transfer does not change the main conclusions and estimates regarding isogenization-induced transpositions.