ELT-5 and ELT-6 are required continuously to regulate epidermal seam cell differentiation and cell fusion in C. elegans.

TitleELT-5 and ELT-6 are required continuously to regulate epidermal seam cell differentiation and cell fusion in C. elegans.
Publication TypeJournal Article
Year of Publication2001
AuthorsKoh K, Rothman JH
Date Published2001 Aug
KeywordsAmino Acid Sequence, Animals, Caenorhabditis elegans, Caenorhabditis elegans Proteins, Cell Differentiation, Cell Fusion, Cell Lineage, DNA-Binding Proteins, Enhancer Elements, Genetic, Epithelial Cells, GATA Transcription Factors, Gene Expression Regulation, Developmental, Genes, Essential, Genes, Helminth, Genes, Reporter, Genetic Markers, Helminth Proteins, Larva, Molecular Sequence Data, RNA, Helminth, RNA, Messenger, Sequence Homology, Amino Acid, Transcription Factors, Transcription, Genetic

The C. elegans epidermis is a simple epithelium comprised of three major cell types, the seam, syncytial and P cells. While specification of all major epidermal cells is known to require the ELT-1 GATA transcription factor, little is known about how the individual epidermal cell types are specified. We report that elt-5 and -6, adjacent genes encoding GATA factors, are essential for the development of the lateral epidermal cells, the seam cells. Inhibition of elt-5 and -6 function by RNA-mediated interference results in penetrant late embryonic and early larval lethality. Seam cells in affected animals do not differentiate properly: the alae, seam-specific cuticular structures, are generally absent and expression of several seam-specific markers is blocked. In addition, elt-3, which encodes another GATA factor normally expressed in non-seam epidermis, is often ectopically expressed in the seam cells of affected animals, demonstrating that ELT-5 and -6 repress elt-3 expression in wild-type seam cells. Seam cells in affected animals often undergo inappropriate fusion with the epidermal syncytia. Interference of elt-5 and -6 function during larval development can cause fusion of all seam cells with the surrounding syncytia and pronounced defects in molting. elt-5 and -6 are both expressed in seam cells and many other cells, and are apparently functionally interchangeable. Their expression is controlled by separable tissue-specific regulatory elements and the apportionment of monocistronic versus dicistronic transcription of both genes appears to be subject to cell-type-specific regulation. Collectively, these findings indicate that elt-5 and -6 function continuously throughout C. elegans development to regulate seam cell differentiation and cell fusion.

Alternate JournalDevelopment
PubMed ID11532911
Grant ListHD37487 / HD / NICHD NIH HHS / United States