PT - JOURNAL ARTICLE AU - Gloor, GB AU - Nassif, NA AU - Johnson-Schlitz, DM AU - Preston, CR AU - Engels, WR TI - Targeted gene replacement in Drosophila via P element-induced gap repair AID - 10.1126/science.1653452 DP - 1991 Sep 06 TA - Science PG - 1110--1117 VI - 253 IP - 5024 4099 - http://science.sciencemag.org/content/253/5024/1110.short 4100 - http://science.sciencemag.org/content/253/5024/1110.full SO - Science1991 Sep 06; 253 AB - Transposable elements of the P family in Drosophila are thought to transpose by a cut-and-paste process that leaves a double-strand gap. The repair of such gaps resulted in the transfer of up to several kilobase pairs of information from a homologous template sequence to the site of P element excision by a process similar to gene conversion. The template was an in vitro-modified sequence that was tested at various genomic positions. Characterization of 123 conversion tracts provided a detailed description of their length and distribution. Most events were continuous conversion tracts that overlapped the P insertion site without concomitant conversion of the template. The average conversion tract was 1379 base pairs, and the distribution of tract lengths fit a simple model of gap enlargement. The conversion events occurred at sufficiently high frequencies to form the basis of an efficient means of directed gene replacement.