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.

Cloning a Gene Encoding a Protein in the Muscle Dense Bodies

R. Barstead and R. Waterston

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