A germline clone screen for fremale meiotic mutants in Drosophilia.

Drosophila is an excellent system in which to investigate the molecular biology of meiosis. A large number of mutants that affect meiosis have been discovered through genetic screens in Drosophila. However, the designs of most previous screens did not allow the recovery of mutations in essential genes. Here we describe a genetic screen that can recover mutants in essential genes that are also required during female meiosis. Thus far, we have conducted screens for meiotic mutants on chromosome arms 2L and 3R. We utilize the FLP-FRT technology to generate and select for homozygous mutant germline clones within heterozygotes. The clones are assayed for autosomal meiotic nondisjunction by crossing clone-bearing females to males that carry a compound autosome (C(3)EN to screen 2L and C(2)EN to screen 3R). Progeny from this cross can only arise from a homozygous mutant germline clone in which nondisjunction occurred during meiosis. Since the rare progeny will be heterozygous for the mutagenized chromosome arm, they are used to isolate a stock of the putative meiotic mutant through a subsequent series of crosses. Total 25,571 chromosome arms 3R and 20,817 chromosome arms 2L have been screened. Twelve mutants have been recovered (10 for 3R and 2 for 2L). Three of these are homozygous lethal. We are currently mapping these mutants and characterizing their phenotypes.

* Ong, S.K, S. Hawley and S. Page. University of Missouri--Kansas City and Stowers Institute for Medical Research, Kansas City.