[
East Coast Worm Meeting,
2000]
The database compiled by the C. elegans Genome Sequencing Consortium includes a total of 23 additional degenerin-related genes. Our characterization of these genes has led the determination of the expression pattern of eight previously uncharacterized degenerins: C24G7.2, C24G7.4, F23B2.3, T28B8.5, T28D9.7, T28F2.7, T28F4.2 and ZK770.1. This analysis revealed that members of the degenerin family function in a variety of cell types ranging from neurons to muscles and epithelia. Some of these degenerin-like genes are expressed in nose touch neurons and could thus be candidates for the elusive mechanosensory channel in those cells. In support of this notion, dsRNA mediated interference with the expression of these degenerins largely decreases response to nose touch. In addition, we have found degenerin-like genes to be expressed in body touch neurons and motorneurons of the ventral nerve cord where they could co-assemble with known degenerins to mediate the mechanosensory properties of these cells. Specific degenerins are expressed in the excretory canal cell which, in the nematode, is the functional equivalent of the kidney. It is intriguing that in mammals, degenerin homologues function in this organ to regulate electrolyte balance. We will present detailed expression patterns at the meeting. Our observations indicate, that contrary to what is probably expected for such a multi-gene family, closely related in sequence members of the degenerin group are not functionally redundant. In an effort to assign any of these genes to known genetic loci, we are currently attempting to complement closely linked candidate mutations and we are also screening deletion libraries for null alleles.