ARE VITELLIN AND VITELLOGENIN CODED BY ONE GENE IN THE MARINE SHRIMP PENAEUS-SEMISULCATUS

A cDNA clone encoding a female-specific ovarian protein (presumably vi tellin, Vt) has been isolated from a cDNA library prepared from poly ( A)(+) RNA extracted from vitellogenic ovaries of the shrimp Penaeus se misulcatus. The cDNA library was constructed and screened using a majo r cDNA band which was observed following analysis of total cDNA produc ts by gel electrophoresis. This band, as well as the cDNA insert purif ied from the library, was estimated to have 1.1 kb. Both hybridized to mRNA prepared from ovaries or hepatopancreas (HEP) of vitellogenic fe males and showed a faint signal with ovaries from non-vitellogenic fem ales, but did not hybridize to HEP from non-vitellogenic females or to HEP from males or testes. The size of the transcripts from the ovary and HEP was estimated to be 1.1 kb, similar to that of the cDNA insert , suggesting that a full length cDNA had been synthesized. Furthermore , the identical sizes of the transcripts from ovary and HEP and the ab ility of the ovarian cDNA to detect a transcript in HEP mRNA suggest t hat Vt from the ovary and vitellogenin (Vg) from HEP are the gene prod ucts of one gene. Alternatively, the homology between Vt and Vg is ver y high.