Possible Distorting Effects of Gef26 in Drosophila Melanogaster

Segregation distortion is a meiotic drive system that results in the favorable inheritance of the SD chromosome over the SD+counterpart. SD produces a malfunctioning form of RanGAP, instead of being able to move in and out of the nucleus this truncated anGAP is unable to be exported and therefore aggregates within the nucleus. This appears to affect RspS during the condensation phase of spermatogenesis, but the exact mechanism for this is unknown. In order to further understand the working components of this system, specific deletions within the second chromosome were studied. The study was conducted systematically by beginning with larger deletions that had previously shown distortion and slowly reducing the size of the deletion. When these deletion stocks were combined with SD-5r7, with RspS on the Y chromosome it was found that a deletion of the region 26C1;26D1 displayed distortion whereas deletion of the region 26C3;26D1 did not. When a deletion of the 26C2;26C3 region was tested distortion was observed. Within this region the genes Cpr and Gef26 are of particular interest. Stocks containing a mutation in Cpr did not demonstrate distortion when combined with SD-5r7. However, when a stock containing a mutation in the gene Gef26 was combined with SD-5r7, distortion was noted. These results suggest that better understanding of the gene Gef26, and its function within the cell during spermatogenesis, would shed some light as to how segregation distortion takes place on a molecular level