Worm Breeder's Gazette 9(3): 60
These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.
The monoclonal antibody MH24, (Francis and Waterston, JBC 1985), which stains the muscle dense bodies and which detects two proteins of 107 and 110 kdaltons on a western blot and used to screen an N2 genomic DNA expression library, (Barstead and Waterston, WBG vol. 9, no.l, 1985). Three positives were recovered, one of which made a -gal fusion protein which was recognized by both MH24 and a rabbit serum made against these two proteins and an -actinin like protein, (also at 107 kdaltons). The serum also recognizes a few uncharacterized peptides on a western blot. Subclones of this clone hybridize to a poly A+ RNA of 3.6 kb, approximately the same size as the paramyosin message which produces a 103 kd protein. Southern blot analysis of restriction enzyme digests of N2 DNA show a single band for all enzymes which do not cut within the cloned sequence. We infer then that this sequence is present as a single copy in the haploid genome. We recovered clones from an MbvoI-partial library in -1059. Four clones were characterized and all were found to overlap with the original 1.5 kb sequence as well as with each other. Two of these were sent to the MRC where they were matched by John Sulston and Alan Coulson to a contig which also includes a gene that probably encodes a polymerase III subunit, (D. sird and D. Riddle, personal communication) . This contig had already been mapped by Donna Albertson to the left half of chromosome IV. The gene defined by our clone has been named deb-l in anticipation that further investigation will confirm that it does encode a protein in the dense body. We have detected an RFLP between Bristol and sergerac, and are currently using this to refine the position on the genetic m.ap. Since deb-l is a single copy gene, and it has not come out of screens for muscle-affecting unc mutants, we are assuming that the gene encodes an essential function. Therefore once to investigate affect deb-l.we have determined its position on the genetic map we intend lethal mutations in the region to identify those which