The mariner transposable element in natural populations of Drosophila teissieri.

The mariner transposable elements of several natural populations of Drosophila teissieri, a rainforest species endemic to tropical Africa, were studied. Natural populations trapped along a transect from Zimbabwe to the Ivory Coast were analyzed by Southern blotting, in situ hybridization, cloning, and sequencing of PCR products. The Brazzaville population had some full-length elements, while the remaining populations had mainly deleted elements. The main class of deleted elements lacked a 500-bp segment. A mechanism is proposed that could generate such elements rapidly. In situ hybridizations showed that there are no mariner elements in pericentromeric heterochromatin. Finally, the phylogeny of the Mos1-like mariner full-length elements is consistent with vertical transmission from the ancestor of the melanogaster subgroup.