Program in Molecular Medicine
Biochemistry | Developmental Biology | Genetics | Genomics | Molecular Biology | Molecular Genetics
Gene expression in early animal embryogenesis is in large part controlled post-transcriptionally. Maternally contributed microRNAs may therefore play important roles in early development. We elucidated a major biological role of the nematode mir-35 family of maternally contributed essential microRNAs. We show that this microRNA family regulates the sex determination pathway at multiple levels, acting both upstream of and downstream from her-1 to prevent aberrantly activated male developmental programs in hermaphrodite embryos. Both of the predicted target genes that act downstream from the mir-35 family in this process, suppressor-26 (sup-26) and NHL (NCL-1, HT2A, and LIN-41 repeat) domain-containing-2 (nhl-2), encode RNA-binding proteins, thus delineating a previously unknown post-transcriptional regulatory subnetwork within the well-studied sex determination pathway of Caenorhabditis elegans Repression of nhl-2 by the mir-35 family is required for not only proper sex determination but also viability, showing that a single microRNA target site can be essential. Since sex determination in C. elegans requires zygotic gene expression to read the sex chromosome karyotype, early embryos must remain gender-naïve; our findings show that the mir-35 family microRNAs act in the early embryo to function as a developmental timer that preserves naïveté and prevents premature deleterious developmental decisions.
embryonic development, maternal control, microRNAs, mir-35–41, mir-35–42, sex determination
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© 2017 McJunkin and Ambros. Publisher PDF posted after 6 months as allowed by the publisher's author rights policy at http://genesdev.cshlp.org/site/misc/terms.xhtml.
DOI of Published Version
McJunkin K, Ambros V. A microRNA family exerts maternal control on sex determination in C. elegans. Genes Dev. 2017 Feb 15;31(4):422-437. doi:10.1101/gad.290155.116. Epub 2017 Mar 9. PubMed PMID: 28279983; PubMed Central PMCID: PMC5358761. Link to article on publisher's website
Genes and development
McJunkin, Katherine and Ambros, Victor R., "A microRNA family exerts maternal control on sex determination in C. elegans" (2017). Program in Molecular Medicine Publications and Presentations. 68.
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