ISOLATION, IMMUNOCHEMICAL DETECTION, AND OBSERVATIONS OF THE INSTABILITY OF VITELLOGENIN FROM 4 TELEOSTS

Vitellogenin was purified from plasma of estradiol-17beta-treated cod (Gadus morhua) rainbow trout (Oncorhynchus mykiss), turbot (Scophthalm us maximus), and wolffish (Anarhichas lupus) by precipitation with EDT A:mg2+, distilled water, and high-performance ion-exchange chromatogra phy. Vitellogenin of high purity was obtained by precipitation followe d by chromatography, as evaluated by an homologous antiserum developed for each species. The instability of vitellogenin demanded consistent low temperature and the use of protease inhibitor before blood sampli ng. When the necessary precautions were taken, vitellogenin from rainb ow trout, turbot, and wolffish eluted as one regular peak during chrom atography. Cod vitellogenin eluted as two peaks and these demonstrated identical migration patterns on SDS-PAGE. The observed differences in stability between the four species suggest that isolation procedures should be modified according to the requirements for each species. Ele ctrophoresis of plasma from treated fish revealed the presence of seve ral smaller proteins, with a molecular mass around 50 kDa, that were c onsidered to be vitelline envelope proteins. Other minor plasma protei ns were immunoreactive to antisera, directed against vitellogenin and therefore judged to be fragments of degraded vitellogenin. (C) 1993 Wi ley-Liss, Inc.