The Caenorhabditis elegans hunchback-like gene lin-57/hbl-1 controls developmental time and is regulated by microRNAs.
Temporal control of development is an important aspect of pattern formation that awaits complete molecular analysis. We identified lin-57 as a member of the C. elegans heterochronic gene pathway, which ensures that postembryonic developmental events are appropriately timed. Loss of lin-57 function causes the hypodermis to terminally differentiate and acquire adult character prematurely. lin-57 is hbl-1, revealing a role for the worm hunchback homolog in control of developmental time. Significantly, fly hunchback (hb) temporally specifies cell fates in the nervous system. The hbl-1/lin-57 3'UTR is required for postembryonic downregulation in the hypodermis and nervous system and contains multiple putative binding sites for temporally regulated microRNAs, including let-7. Indeed, we find that hbl-1/lin-57 is regulated by let-7, at least in the nervous system. Examination of the hb 3'UTR reveals potential binding sites for known fly miRNAs. Thus, evolutionary conservation of hunchback genes may include temporal control of cell fate specification and microRNA-mediated regulation.
Department of Genetics, University of Minnesota, 6-160 Jackson Hall, 321 Church Street SE, Minneapolis, MN 55455, USA.
Juan E
JE
Abrahante
Aric L
AL
Daul
Ming
M
Li
Mandy L
ML
Volk
Jason M
JM
Tennessen
Eric A
EA
Miller
Ann E
AE
Rougvie
D020413:3' Untranslated Regions / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000254:growth & development*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004843:Epistasis, Genetic; D005260:Female; D018507:Gene Expression Regulation, Developmental; D008124:Locomotion; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D034622:RNA Interference; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D020413:3' Untranslated Regions; D029742:Caenorhabditis elegans Proteins; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D035683:MicroRNAs; D014157:Transcription Factors; C061245:hb protein, Drosophila; C474486:hbl-1 protein, C elegans