Spoink, a LTR retrotransposon, invadedD. melanogasterpopulations in the 1990s

Abstract

AbstractDuring the last few centuriesD. melanogasterpopulations were invaded by several transposable elements, the most recent of which was thought to be theP-element between 1950 and 1980. Here we describe a novel TE, which we namedSpoink, that has invadedD. melanogaster. It is a 5216nt LTR retrotransposon of the Ty3/gypsy superfamily. Relying on strains sampled at different times during the last century we show thatSpoinkinvaded worldwideD. melanogasterpopulations after theP-element between 1983 and 1993. This invasion was likely triggered by a horizontal transfer from theD. willistonigroup, much as theP-element.Spoinkis probably silenced by the piRNA pathway in natural populations and about 1/3 of the examined strains have an insertion into a canonical piRNA cluster such as42AB. Given the degree of genetic investigation ofD. melanogasterit is surprising thatSpoinkwas able to invade unnoticed.