The vicinity of a broken chromosome end affects P element mobilization in Drosophila melanogaster.

Broken chromosome ends are believed to be capped by a terminal protein complex, and can be maintained in Drosophila melanogaster for many generations. We investigated whether the vicinity of a chromosome end affected P element mobilization and the subsequent repair of the resulting DNA lesion. High levels of P element excision were observed when at least 5 kb of DNA was located between the P element and the end of the chromosome, but recovery of chromosomes from which the P element had been excised was greatly reduced when the chromosome end was positioned less than 5 kb away from the original P element insertion site. Moreover, when the P element was mobilized in terminal deficiency ( y (TD )) alleles, excision events were accompanied by deletions of sequences originally located distal to the P element.