A cohort of Caenorhabditis species lacking the highly conserved let-7 microRNA. Issue 3 (28th January 2021)

• Record Type: Journal Article
• Authors: Nelson, Charles; Ambros, Victor
• Editors: Kim, J. K
• Is Part Of: G3. Volume 11:Issue 3(2021)
• Publication Date: 2021-01-28
• Subjects: let-7 microRNA -- Elegans supergroup -- Elegans group -- Japonica group -- Caenorhabditis sulstoni -- Caenorhabditis macrosperma -- Caenorhabditis elegans; Genetics -- Research -- Periodicals; Genomics -- Periodicals; Genetics; Genomics; Genes; Genetics -- Research; Genomics; Electronic journals; Periodical; Periodicals; Fulltext; Internet Resources; Periodicals; 572.8
• DOI: 10.1093/g3journal/jkab022
• Languages: English
• ISSNs: 2160-1836

Abstract

Abstract: The let-7 gene encodes a highly conserved microRNA with critical functions integral to cell fate specification and developmental progression in diverse animals. In Caenorhabditis elegans, let-7 is a component of the heterochronic (developmental timing) gene regulatory network, and loss-of-function mutations of let-7 result in lethality during the larval to adult transition due to misregulation of the conserved let-7 target, lin-41 . To date, no bilaterian animal lacking let-7 has been characterized. In this study, we identify a cohort of nematode species within the genus Caenorhabditis, closely related to C. elegans, that lack the let-7 microRNA, owing to absence of the let-7 gene. Using Caenorhabditis sulstoni as a representative let-7- lacking species to characterize normal larval development in the absence of let-7, we demonstrate that, except for the lack of let-7, the heterochronic gene network is otherwise functionally conserved. We also report that species lacking let-7 contain a group of divergent let-7 paralogs—also known as the let-7- family of microRNAs—that have apparently assumed the role of targeting the LIN-41 mRNA.