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.
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.