The C. elegans hunchback Homolog, hbl-1, Controls Temporal Patterning and Is a Probable MicroRNA Target

• Published in: Developmental cell 2003-05, Vol.4 (5), p.639-650
• Main Authors: Lin, Shin-Yi, Johnson, Steven M, Abraham, Mary, Vella, Monica C, Pasquinelli, Amy, Gamberi, Chiara, Gottlieb, Ellen, Slack, Frank J
• Format: Article
• Language: English
• Subjects: 3' Untranslated Regions - genetics; 3' Untranslated Regions - metabolism; Alleles; Amino Acid Sequence; Animals; Base Sequence; Body Patterning; Caenorhabditis elegans - embryology; Caenorhabditis elegans - genetics; Caenorhabditis elegans - metabolism; Caenorhabditis elegans Proteins - genetics; Caenorhabditis elegans Proteins - metabolism; Cell Lineage; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Down-Regulation; Drosophila Proteins - genetics; Drosophila Proteins - metabolism; Exons; Gene Expression Regulation, Developmental; Introns; MicroRNAs - genetics; MicroRNAs - metabolism; Molecular Sequence Data; Mutation; Repressor Proteins - metabolism; RNA Interference; Sequence Homology, Amino Acid; Time Factors; Transcription Factors - genetics; Transcription Factors - metabolism
• ISSN: 1534-5807; 1878-1551
• DOI: 10.1016/S1534-5807(03)00124-2

hunchback regulates the temporal identity of neuroblasts in Drosophila. Here we show that hbl-1, the C. elegans hunchback ortholog, also controls temporal patterning. Furthermore, hbl-1 is a probable target of microRNA regulation through its 3′UTR. hbl-1 loss-of-function causes the precocious expression of adult seam cell fates. This phenotype is similar to loss-of-function of lin-41, a known target of the let-7 microRNA. Like lin-41 mutations, hbl-1 loss-of-function partially suppresses a let-7 mutation. The hbl-1 3′UTR is both necessary and sufficient to downregulate a reporter gene during development, and the let-7 and lin-4 microRNAs are both required for HBL-1/GFP downregulation. Multiple elements in the hbl-1 3′UTR show complementarity to regulatory microRNAs, suggesting that microRNAs directly control hbl-1. MicroRNAs may likewise function to regulate Drosophila hunchback during temporal patterning of the nervous system.