Abstract
P-element induced double strand break repair in Drosophila can be used for studying the mechanisms of homologous recombination in higher eucaryotes as well as for targeting and converting genes in their original chromosomal environment. So far studies on the molecular mechanisms of recombination were mainly possible in fungi. Even though gene targeting through homologous recombination is becoming a routine instrument in the mouse the underlying molecular events are by no means clear. The genetics of Drosophila provides a powerful tool to study the basics of gene targeting and gene conversion events in higher eucaryotes.