Title

Pheromones and Nutritional Signals Regulate the Developmental Reliance on let-7 Family MicroRNAs in C. elegans

UMMS Affiliation

Program in Molecular Medicine; Graduate School of Biomedical Sciences

Publication Date

2019-06-03

Document Type

Article

Disciplines

Developmental Biology

Abstract

Adverse environmental conditions can affect rates of animal developmental progression and lead to temporary developmental quiescence (diapause), exemplified by the dauer larva stage of the nematode Caenorhabditis elegans (C. elegans). Remarkably, patterns of cell division and temporal cell-fate progression in C. elegans larvae are not affected by changes in developmental trajectory. However, the underlying physiological and gene regulatory mechanisms that ensure robust developmental patterning despite substantial plasticity in developmental progression are largely unknown. Here, we report that diapause-inducing pheromones correct heterochronic developmental cell lineage defects caused by insufficient expression of let-7 family microRNAs in C. elegans. Moreover, two conserved endocrine signaling pathways, DAF-7/TGF-beta and DAF-2/Insulin, that confer on the larva diapause and non-diapause alternative developmental trajectories interact with the nuclear hormone receptor, DAF-12, to initiate and regulate a rewiring of the genetic circuitry controlling temporal cell fates. This rewiring includes engagement of certain heterochronic genes, lin-46, lin-4, and nhl-2, that are previously associated with an altered genetic program in post-diapause animals, in combination with a novel ligand-independent DAF-12 activity, to downregulate the critical let-7 family target Hunchback-like-1 (HBL-1). Our results show how pheromone or endocrine signaling pathways can coordinately regulate both developmental progression and cell-fate transitions in C. elegans larvae under stress so that the developmental schedule of cell fates remains unaffected by changes in developmental trajectory.

Keywords

ascarosides, dauer larva, developmental robustness, endocrine signaling, heterochronic genes, let-7, microRNAs, pheromones, reprogramming, stem cell

DOI of Published Version

10.1016/j.cub.2019.04.034

Source

Curr Biol. 2019 Jun 3;29(11):1735-1745.e4. doi: 10.1016/j.cub.2019.04.034. Epub 2019 May 16. Link to article on publisher's site

Journal/Book/Conference Title

Current biology : CB

Related Resources

Link to Article in PubMed

PubMed ID

31104929

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