A role for WDR5 in TRA-1/Gli mediated transcriptional control of the sperm/oocyte switch in C. elegans

• Type of Material: Article
• Authors: Tengguo Li, Emory University; William G Kelly, Emory University
• Language: English
• Date: 2014-05-01
• Publisher: Oxford University Press (OUP)
• Publication Version: Final Published Version
• Copyright Statement: © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.
• License: Creative Commons Attribution 3.0 Unported
• Final Published Version (URL): http://nar.oxfordjournals.org/content/42/9/5567
• Title of Journal or Parent Work: Nucleic Acids Research
• ISSN: 0305-1048
• Volume: 42
• Issue: 9
• Start Page: 5567
• End Page: 5581
• Grant/Funding Information: National Institutes of Health (NIH) [GM 101040 to W.G.K.].
• Research Categories: Biology, General

Abstract

The hermaphrodite germline of Caenorhabditis elegans initially engages in spermatogenesis and then switches to oogenesis during late stages of larval development. TRA-1, a member of the Ci/Gli family of transcriptional repressors, plays an essential role in this switch by repressing genes that promote spermatogenesis. WDR5 proteins are conserved components of histone methyltransferase complexes normally associated with gene activation. However, two C. elegans WDR5 homologs, wdr-5.1 and wdr-5.2 are redundantly required for normal TRA-1 dependent repression, and this function is independent of their roles in histone methylation. Animals lacking wdr-5.1/wdr-5.2 function fail to switch to oogenesis at 25°C, resulting in a masculinization of germline (Mog) phenotype. The Mog phenotype is caused by ectopic expression of fog-3, a direct target of TRA-1 repression. WDR-5.1 associates with the fog-3 promoter and is required for TRA-1 to bind to fog-3 promoter. Other direct targets of TRA-1 are similarly derepressed in the double mutant. These results show that WDR5 plays a novel and important role in stabilizing transcriptional repression during C. elegans sex determination, and provide evidence that this important protein may operate independently of its established role in histone methyltransferase complexes.