A microRNA family exerts maternal control on sex determination in C. elegans

作者：McJunkin Katherine; Ambros Victor^*

来源：Genes & Development, 2017, 31(4): 422-437.

DOI：10.1101/gad.290155.116

• microRNAs
• embryonic development
• maternal control
• mir-35-41
• mir-35-42
• sex determination

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-naive; our findings show that the mir-35 family microRNAs act in the early embryo to function as a developmental timer that preserves naivete and prevents premature deleterious developmental decisions.

• 出版日期2017-2-15