title: Post-embryonic expression of C. elegans microRNAs belonging to the lin-4 and let-7 families in the hypodermis and the reproductive system.
abstract: MicroRNAs (miRNAs) are regulatory molecules that negatively control gene expression by binding to complementary sequences on target mRNAs. The most thoroughly characterized miRNAs, lin-4 and let-7, direct cell fate determination during the larval transitions in C. elegans and act as key regulators of temporal gene expression. lin-4 and let-7 are founding members of two distinct families of miRNA genes sharing strong sequence homology primarily in the 5' end of the mature miRNAs. In this report, we characterize the temporal and spatial expression patterns of lin-4 and let-7 family members using northern blot analysis and mir::gfp fusion studies. Our results show that lin-4 and let-7 homologues possess distinct temporal and spatial expression patterns during nematode development and that known heterochronic genes regulate their expression. We find that certain lin-4 and let-7 family members display overlapping expression patterns in the hypodermis and the reproductive system, suggesting that combinations of miRNAs from across families may control common developmental events.
authors.affiliation: Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, CT 06520, USA.
authors.forename: A
authors.initials: A
authors.lastname: Esquela-Kerscher
authors.forename: S M
authors.initials: SM
authors.lastname: Johnson
authors.forename: L
authors.initials: L
authors.lastname: Bai
authors.forename: K
authors.initials: K
authors.lastname: Saito
authors.forename: J
authors.initials: J
authors.lastname: Partridge
authors.forename: K L
authors.initials: KL
authors.lastname: Reinert
authors.forename: F J
authors.initials: FJ
authors.lastname: Slack
mesh_terms: D000818:Animals; D015152:Blotting, Northern; D017173:Caenorhabditis elegans / Q000254:growth & development / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D017931:DNA Primers; D018507:Gene Expression Regulation, Developmental; D006066:Gonads / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D040521:Subcutaneous Tissue / Q000378:metabolism*
chemical_list: D029742:Caenorhabditis elegans Proteins; C410905:DAF-12 protein, C elegans; D017931:DNA Primers; D035683:MicroRNAs; D018160:Receptors, Cytoplasmic and Nuclear; D012097:Repressor Proteins; C474488:let-7 microRNA, C elegans; C452194:lin-4 microRNA, C elegans; D049452:Green Fluorescent Proteins