RETROTRANSPOSITION OF THE DROSOPHILA LINE-I ELEMENT CAN INDUCE DELETION IN THE TARGET DNA - A SIMPLE-MODEL ALSO ACCOUNTING FOR THE VARIABILITY OF THE NORMALLY OBSERVED TARGET SITE DUPLICATIONS

Retrotransposition of the Drosophila melanogaster LINE I element norma lly generates target site duplications of variable length, as classica lly observed for most LINE elements. Using an I element ''marked'' wit h an indicator gene for in vivo detection of transposition that we pre viously developed, we show that deletion in the target DNA can also ta ke place, as a direct consequence of I element transposition. We propo se a simple model accounting for the generation of both target site du plications of variable length and target DNA deletions, which relies u pon template switching of the LINE-encoded reverse transcriptase betwe en single-strand DNA at the target site and the LINE template. (C) 199 4 Academic Press, Inc.