Worm Breeder's Gazette 8(1): 44

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 Relationship Between the Yolk Proteins and the Cloned Yolk Protein Gene Family

J. Cane, E. Zucker, B. Sharrock, T. Blumenthal

Hybrid arrest translation has now demonstrated the relationship 
between the yolk proteins and the 5 gene yolk protein gene family 
which we have described previously (1983, C.  elegans meeting).  It 
turns out that only the doublet of 170K proteins is encoded by these 
genes.  The upper member of the doublet is encoded by the subfamily 
containing yp3, 4, and 5, while the lower member is encoded by the yp1 
and 2 subfamily.  When single-stranded DNA from various M13 subclones 
of the genes is hybridized to total C.  elegans RNA prior to 
translation, there are two alterations in the pattern of proteins 
synthesized: one of the yp170 bands disappears and a new polypeptide 
appears at a position consistent with it being a truncated polypeptide 
whose translation terminated at the site of DNA-RNA hybridization.  
These truncated polypeptides are all immunoprecipitable with anti-
yp170, but not with anti-yp115 or anti-yp88 IgGs.  None of the clones 
eliminates the yp115/yp88 precursor (see Sharrock, this Newsletter) 
from the pattern of translation products.  Presumably this polypeptide 
is encoded by a gene or genes as yet uncloned.
We don't yet know whether all five of the yp170 genes are actually 
transcribed and translated.  If they are all expressed, then there 
must actually be five distinct proteins present in the yp170 doublet.  
We have isolated several cDNA clones which correspond to yp2 and yp5 
but we have not found any which correspond to the other genes.  
However, DNA sequence analysis demonstrates a highly asymmetric codon 
usage for all five genes suggesting that all five are expressed.