The let-7 MicroRNA Family Members mir-48, mir-84, and mir-241 Function Together to Regulate Developmental Timing in Caenorhabditis Elegans

Dev Cell. 2005 Sep;9(3):403-14. doi: 10.1016/j.devcel.2005.07.009.

Abstract

The microRNA let-7 is a critical regulator of developmental timing events at the larval-to-adult transition in C. elegans. Recently, microRNAs with sequence similarity to let-7 have been identified. We find that doubly mutant animals lacking the let-7 family microRNA genes mir-48 and mir-84 exhibit retarded molting behavior and retarded adult gene expression in the hypodermis. Triply mutant animals lacking mir-48, mir-84, and mir-241 exhibit repetition of L2-stage events in addition to retarded adult-stage events. mir-48, mir-84, and mir-241 function together to control the L2-to-L3 transition, likely by base pairing to complementary sites in the hbl-1 3' UTR and downregulating hbl-1 activity. Genetic analysis indicates that mir-48, mir-84, and mir-241 specify the timing of the L2-to-L3 transition in parallel to the heterochronic genes lin-28 and lin-46. These results indicate that let-7 family microRNAs function in combination to affect both early and late developmental timing decisions.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Caenorhabditis elegans / growth & development*
  • Caenorhabditis elegans / metabolism
  • Caenorhabditis elegans / ultrastructure
  • Caenorhabditis elegans Proteins / genetics*
  • Caenorhabditis elegans Proteins / metabolism*
  • Gene Deletion
  • Gene Expression Regulation, Developmental*
  • Genotype
  • MicroRNAs / genetics*
  • MicroRNAs / metabolism*
  • Mutation
  • Phylogeny
  • Time Factors

Substances

  • Caenorhabditis elegans Proteins
  • MicroRNAs
  • let-7 microRNA, C elegans