Thecopiaretrotransposon and horizontal transfer inDrosophila willistoni

Abstract

SummaryThe copia element is a retrotransposon that is hypothesized to have been horizontally transferred fromDrosophila melanogasterto some populations ofDrosophila willistoniin Florida. Here we have used PCR and Southern blots to screen for sequences similar tocopiaelement in South American populations ofD. willistoni, as well as in strains previously shown to be carriers of the element. We have not found the canonical copia element in any of these populations. Unlike thePelement, which invaded theD. melanogastergenome fromD. willistoniand quickly spread worldwide, the canonicalcopiaelement appears to have transferred in the opposite direction and has not spread. This may be explained by differences in the requirements for transposition and in the host control of transposition.