Asymmetric exchange is associated with P element induced male recombination in Drosophila melanogaster

Abstract

Spontaneous meiotic recombination events do not normally occur in the male germ line of Drosophila melanogaster. However, such events are induced in males when a P transposable element or a source of P element encoded transposase protein is present in its genome. This report concerns a molecular analysis of the meiotic exchanges that were induced in the male Drosophila by P elements within a genetically marked region of the third chromosome. The marked region also harbors a single P-element called P(IArB). Fifty-six percent of the P(IArB) region crossovers indicated some alterations in the P element 5′ fragment. Such alterations appear to be related to asymmetric or unequal genetic exchanges. Finally, P(IArB) excision was found to be independent of P(IArB) region crossover events.