Worm Breeder's Gazette 8(3): 62

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 Yolk Protein Gene Family of C. elegans: YP6, the Gene for the Precursor to yp115 and yp88

J. Spieth, T. Blumenthal

Four yolk proteins have been identified in C.  elegans: Two closely 
related proteins of approximately 170,000 daltons (yp170A and yp170B), 
and two other polypeptides of 115,000 daltons (yp115) and 88,000 
daltons (yp88) (Sharrock, 1983. Develo. Biol, 96, 182-188). yp115 and 
yp88 have been shown to be derived from a 180,000 dalton precursor (
Sharrock, 1984, J. Mol. Biol 174, 419-431).  We recently have shown 
that yp170A and yp170B are encoded by a five gene family (YP1-5) (
Blumenthal et al.. 1984, J. Mol. Biol. 174, 1-18). We have now cloned 
a developmentally-regulated gene that, based on the timing of 
expression, size and abundance of the mRNA and finally, hybrid-arreat 
translation experiments, encodes the 180.000 dalton precursor to yp115 
and yp88 .
The gene (YP6) was cloned from a C. rary by 
selecting abundantly expressed sequences that were adult specific but 
did not hybridize to YP1-5. Genomic clones were selected from John 
Karn's lambda1059 library.
Based on genomic Southern blots the precursor to yp115 and yp88 is 
encoded by a single-copy gene. It is about 5.5 kb long and hybridizes 
to a 5.2 kb RNA. YP6 RNA is as abundant in adult hermaphrodites as is 
the RNA from the YP1-5 gene family but, like YP1-5 RNA, YP6 RNA is not 
detectable in larvae or adult males.
Based on DNA sequence comparison YP6 is distantly related to the YP1-
5 genes suggesting that all of the yolk protein genes evolved from a 
common ancestor.