A multiplex F1 RNAi screen for defects in Drosophila female meiosis
posterposted on 20.04.2020, 22:05 by William D. Gilliland, Denny May, Gabrielle Presbitero, Kelly Conger, Olivia Johnson, Marcin Marciniak, Doreen Elrad
Abstract: Traditional genetic screens to identify genes
required for meiosis induce mutations, make mutated chromosomes homozygous, and then examine progeny of mutant females for evidence of chromosome segregation errors. This requires that mutant females be viable and fertile, and will therefore miss any meiotic genes that are required to produce viable offspring. Our lab is currently screening the germline-specific VALIUM22 collection that was produced by the Harvard TRiP Project, which contains RNAi constructs targeting genes known to be expressed in the germline. By driving RNAi only in the germline, we can test genes that would be lethal if knocked down in all cells, and by examining unfertilized metaphase-arrested mature oocytes by confocal microscopy, we can identify genes even if they would result in sterility.
We are screening this collection to identify genes that disrupt either of two phenotypes: the ability of meiotic chromosomes to undergo congression to a single mass at the end of prometaphase, and the structure of cytological filaments that become heavily decorated with Mps1-GFP during acute hypoxia. As of the time of this meeting, we have tested ~1400 out of the ~1500 lines in the VALIUM22 collection, and have obtained multiple hits for both phenotypes, including several genes that were not known to play a role in meiosis as well as finding the first phenotypes to be associated with multiple previously uncharacterized genes.