[Analysis of changes in MGE localization of Drosophila after selection and temperature treatment using Southern...

For five heterogeneous lines of Drosophila melanogaster (riC, riSN, riSP, riT113, and riT149), patterns of DNA restriction fragments, containing different mobile genetic elements (MGE), were obtained by means of Southern blot hybridization. Using densitometry of gel radioautographs, differences between patterns were estimated and distance matrices and similarity dendrograms constructed. Judging by these dendrograms, lines riSN (selected in negative direction) and riT113 (treated with temperature) are most similar both for patterns of MGEs Dm412, I-3', and jockey; and for the expression of the quantitative character radius incompletus. The similarity in MGE patterns was shown to be determined mainly by more similar spectra of acquisition and loss of bands (fragments), than in the control line (riC). Earlier, the same results were obtained for MGEs Dm412, MDG1, and copia, using in situ hybridization. It is assumed that during selection, a consensus pattern of the selected line is largely formed by transpositions and excisions of MGE, which either modify the expression of adjacent polygenes or mark adjacent polygenes with large effect. Under temperature stress, non-random induced transpositions and excisions generate hot sites and site haplotypes. If they affect polygene expression, they also fall into consensus patterns of contrasting "temperature" lines and form correlation between the character expression and MGE localization pattern.