The Israeli Journal of Aquaculture - Bamidgeh 55(4), 2003
The 7th Annual Dan Popper Symposium


THE VITELLOGENIN GENE IN CRAYFISH: EXPRESSION AND
ENCODED PROTEINS MOBILIZED TO THE OVARY


Eliahu D. Aflalo¹, Isam Khalaila², Simy Weil¹, Carmen Segall·, Claytus Davis³ and Amir Sagi¹*

1 Department of Life Sciences and the Institute for Applied Biosciences, Ben Gurion University of the Negev, P.O.Box 653, Beer Sheva, Israel

2 Institute for Medical Physics und Biophysics, University of Muenster, Robert-Koch-Str.31 ,D-48149 Muenster, Germany

3 Department of Molecular Genetics of Development, Ben Gurion University of the Negev


Abstract

A complete cDNA sequence of the crayfish Cherax quadricarinatus vitellogenin (CqVg) was cloned and sequenced in our laboratory (Genbank accession number AF306784). The CqVg gene was expressed in vivo in the hepatopancreas of secondary-vitellogenic females with the onset of vitellogenesis and in vitro in hepatopancreas primary cell culture up to seven days. Male hepatopancreatic cells did not express this gene in vivo or in vitro (negative control).

Sequence similarities between the complete deduced amino acid sequence of the CqVg cDNA and its presumably high density lipoprotein (HDL) products, i.e., vitellogenin in the hemolymph and vitellin in the ovary, were examined. Predominant proteins from the hemolymph (208, 196, 177 and 80 kDa) and different components of yolk protein vitellin in the ovary (predominantly 177, 155, 106, 95, 86, 75) were separated, analyzed by mass spectrometry for peptide sequences and compared. The observed similarity suggests that HDL proteins from both locations are derived from the same CqVg gene expressed in the hepatopancreas, the protein products of which are transported through the hemolymph and accumulate in the developing oocytes.

*email: sagia@bgumail.bgu.ac.il

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