GENE INTERACTIONS AFFECTING MECHANOSENSORY TRANSDUCTION IN CAENORHABDITIS-ELEGANS

GENETIC screening has identified a group of mec (mechanosensory) genes that are required for the function of a set of six touch-receptor neurons in the nematode Caenorhabditis elegans1,2. Such genes potentially encode components of the mechanosensory apparatus. We have cloned one of these genes, mec-10, which is a member of the degenerin gene family (genes such as mec-4 and deg-1 (refs 3, 4) that can be mutated to cause neurodegeneration). Because components of an amiloride-sensitive sodium channel (alpha, beta and gammarENaC) from rat6-8 share considerable sequence similarity with the C. elegans genes, it is likely that degenerins may function as channel proteins. Here we show that two degenerin homologues (mec-4 and mec-10) are expressed in the same cells, although each provides a unique function. Based on genetic data of mutations affecting mec-10-induced degeneration, we propose that the products of three genes (mec-4, mec-10 and mec-6) form a complex needed for mechanosensation, and that several other mec genes may be important in regulating the putative channel complex.