The gon-1 gene is required for gonadal morphogenesis in Caenorhabditis elegans

In wild-type Caenorhabditis elegans, the gonad is a complex epithelial tube that consists of long arms composed predominantly of germline tissue as we ll as somatic structures specialized for particular reproductive functions. In gon-1 mutants, the adult gonad is severely disorganized with essentiall y no arm extension and no recognizable somatic structure. The developmental defects in gon-1 mutants are limited to the gonad; other cells, tissues, a nd organs appear to develop normally. Previous work defined the regulatory "leader" cells as crucial for extension of the gonadal arms (J. E. Kimble a nd J G White, 1981, Dev. Biol. 81, 208-219). In gon-1 mutants, the leader c ells are specified correctly, but they fail to migrate and gonadal arms are not generated. In addition, gon-1 is required for morphogenesis of the gon adal somatic structures. This second role appears to be independent of that required for leader migration. Parallel studies have shown that gon-1 enco des a secreted metalloprotease (R. Blelloch and J. Kimble, 1999, Nature 399 , 586-590). We discuss how a metalloprotease may control two aspects of gon adal morphogenesis. (C) 1999 Academic Press.