BuT2 is a member of the third major group of hAT transposons and is involved in horizontal transfer events in the genus Drosophila

Abstract

The hAT superfamily comprises a large and diverse array of DNA transposons found in all supergroups of eukaryotes. Here we characterized the Drosophila buzzatii BuT2 element and found that it harbors a five-exon gene encoding a 643-aa putatively functional transposase. Aphylogeny built with 85hAT transposases yielded, in addition to the two major groups already described, Ac and Buster, a thirdone comprising 20 sequences that includes BuT2, Tip100, hAT-4-BM, and RP-hAT1. This third group is here named Tip. In addition, we studied the phylogenetic distribution and evolution of BuT2 by in silico searches and molecular approaches. Our data revealed BuT2 was, most often, vertically transmitted during the evolution of genus Drosophila being lost independently in several species. Nevertheless, we propose the occurrence of three horizontal transfer events to explain its distribution and conservation amongspecies. Another aspect of BuT2 evolution and life cycle is the presence of short related sequences, which contain similar 50 and 30 regions, including the terminal inverted repeats. These sequences that can be considered asminiature inverted repeat transposable elements probably originated by internal deletion of complete copies and show evidences of recent mobilization. © The Author(s) 2014.