Regulation of body length and male tail ray pattern formation of Caenorhabditis elegans by a member of TGF-beta family

We have identified a new member of the TGF-beta superfamily, CET-1, from Ca enorhabditis elegans, which is expressed in the ventral nerve cord and othe r neurons, cet-1 null mutants have shortened bodies and male tail abnormal phenotype resembling sma mutants, suggesting cet-1, sma-2, sma-3 and sma-l share a common pathway. Overexpression experiments demonstrated that cet-1 function requires wild-type srna genes, Interestingly, CET-1 appears to aff ect body length in a dose-dependent manner. Heterozygotes for cet-1 display ed body lengths ranging between null mutant and wild type, and overexpressi on of CET-1 in wild-type worms elongated body length close to ion mutants. In male sensory ray patterning, lack of cet-1 function results in ray fusio ns, Epistasis analysis revealed that mab-21 lies downstream and is negative ly regulated by the cet-1/sma pathway in the male tail. Our results show th at cet-1 controls diverse biological processes during C. elegans developmen t probably through different target genes.