[Multiple induction of transpositions of Mobile Genetic Element B104 in Drosophila with severe heat shock]

Induction of transpositions by heavy heat shock (HHS) was demonstrated for the copia-like mobile genetic element B104. The probability of transposition induction lambda HHS was equal to 8.1 x 10(-2) per site per spermatozoon per spermatozoon per generation, which is an order of magnitude higher than the upper limit of spontaneous transposition probability estimate, lambda k < 1.7 x 10(-3). "Hot" and "cold" transposition sites were found. Many multisite heat shock haplotypes were shown to be nonrandom combinations of independent single-site transpositions. Multiples of numerous heat shock haplotypes exceeded expected values, which suggest-s that they were selected either in male germline cells or at the level of gametic fertility. These data confirm our earlier results obtained for Dm412. Heat shock transposition induction can be considered as a general property of different copia-like mobile genetic elements in Drosophila.