The endogenous mex-3 3´UTR is required for germline repression and contributes to optimal fecundity in C. elegans

• Published in: PLoS genetics 2021-08, Vol.17 (8), p.e1009775-e1009775
• Main Authors: Albarqi, Mennatallah M Y, Ryder, Sean P
• Format: Article
• Language: English
• Subjects: 3' Untranslated regions; 3' Untranslated Regions - genetics; Animals; Biology and Life Sciences; Breeding success; Caenorhabditis elegans - genetics; Caenorhabditis elegans Proteins - genetics; Caenorhabditis elegans Proteins - metabolism; Cell fate; CRISPR; Cytoplasm; Embryogenesis; Embryonic Development - genetics; Embryos; Fecundity; Fertility - genetics; Gene Expression Regulation, Developmental - genetics; Germ Cells - metabolism; Polyadenine; Polyadenylation; Proteins; Quantitative analysis; Reproduction; Reproductive health; Research and Analysis Methods; RNA, Messenger - metabolism; RNA-binding protein; RNA-Binding Proteins - genetics; RNA-Binding Proteins - metabolism; Sperm; Stem cells; Translation; Uterus
• ISSN: 1553-7404; 1553-7390; 1553-7404
• DOI: 10.1371/journal.pgen.1009775

RNA regulation is essential to successful reproduction. Messenger RNAs delivered from parent to progeny govern early embryonic development. RNA-binding proteins (RBPs) are the key effectors of this process, regulating the translation and stability of parental transcripts to control cell fate specification events prior to zygotic gene activation. The KH-domain RBP MEX-3 is conserved from nematode to human. It was first discovered in Caenorhabditis elegans, where it is essential for anterior cell fate and embryo viability. Here, we show that loss of the endogenous mex-3 3´UTR disrupts its germline expression pattern. An allelic series of 3´UTR deletion variants identify repressing regions of the UTR and demonstrate that repression is not precisely coupled to reproductive success. We also show that several RBPs regulate mex-3 mRNA through its 3´UTR to define its unique germline spatiotemporal expression pattern. Additionally, we find that both poly(A) tail length control and the translation initiation factor IFE-3 contribute to its expression pattern. Together, our results establish the importance of the mex-3 3´UTR to reproductive health and its expression in the germline. Our results suggest that additional mechanisms control MEX-3 function when 3´UTR regulation is compromised.