Characterization of the main egg envelope proteins of the sea bass Dicentrarchus labrax L. (teleostea, serranidae)

Abstract

Fish eggs are surrounded by a resistant acellular coat commonly called the chorion or zona radiata. This study characterizes the eggshell proteinaceous content of unfertilized eggs of the sea bass Dicentrarchus labrax, with a view to the preparation of immunogens. Solubilization of the purified eggshells was achieved in 8 M urea followed by one- and two-dimensional gel electrophoresis. Glycoproteins were detected using concanavalin-A in one and two-dimensional gels, and the principal glycoproteins had a molecular weight of 47 kDa and 170 kDa. Partial purification of a few polypeptides in the 45 kDa to 55 kDa range was achieved by gel filtration chromatography. Although whole eggshells were relatively insoluble even in 8 M urea, partial purification of these polypeptides enable them to dissolve completely in solutions at low ionic strength.

Amino acid composition and endocrine control of vitelline envelope proteins in European sea bass (Dicentrarchus labrax) and gilthead sea bream (Sparus aurata)

“…Both species have three vitelline envelope proteins with molecular masses -50 kDa, whereas the fourth protein has a higher molecular mass, i.e., 90 kDa for European sea bass and 75 kDa for gilthead sea bream. These results are in accordance with a recent study describing that the vitelline envelope of European sea bass is composed of some major proteins with molecular masses -50 kDa (Scapigliati et al, 1994). In the present study, a protein with the molecular mass of 90 control gilthead sea bream; (5,7,9, and 11) plasma from male gilthead sea bream treated with estradiol-17P; (6 and 7), plasma was pretreated with Tris-buffered extraction buffer before dilution with sample buffer as described in materials and methods; (4-7) antiserum directed against gilthead sea bream vitelline envelope proteins diluted 1:SOOO; (8 and 9) antiserum directed against Atlantic halibut vitellogenin diluted 1:24000; (10 and 11) antiserum directed against brown trout vitellogenin diluted 124,000.…”

Gamete interactions in teleost fish: the egg envelope. Basic studies and perspectives as environmental biomonitor

“…Major oocyte envelope constituents have molecular masses ranging between 40 and 130 kDa (Hamazaki et al, 1987a;Cotelli et al, 1988;Begovac and Wallace, 1989;Brivio et al, 1991;Oppen-Berntsen et al, 1990;Hyllner et al, 1991;Scapigliati et al, 1994;Bonsignorio et al, 1996;Berois et al, 2007). The Austrolebias egg envelope protein profi le analyzed by SDS-PAGE shows seven bands in mature oocytes: four major bands with molecular weights of about 45, 97, 120 and 160 kDa.…”

Fine structure of the chorion and micropyle of the sea bass eggDicentrarchus labrax(Teleostea, Percichthydae)

“…The pore canal openings characterize the surface morphology of mature eggs of D. labrax and are a species-specific character of taxonomic value. The relationships between the present morphological data and the biochemical data are relevant (Scapigliati et al, 1994), both being related to the structural strength of D. labrax chorion. Scapigliati et al (1994) determined the polypeptide composition of the sea bass eggshell showing its high resistance to solubilization even in 8 M urea.…”

“…These envelopes have been described with a variety of terms, such as zona radiata, zona pellucida, vitelline membrane or vitelline envelope, primary envelope, egg capsule, and chorion (Anderson, 1967;Laale, 1980;Riehl, 1991;Yamagami et al, 1992). Although originally employed to refer to the membrane surrounding the embryo of amniotes, the term chorion is widely used in current fish literature (Dumont & Brummett, 1980;Mooi et al, 1990;Brivio et al, 1991;Yamagami et al, 1992;Fausto et al, 1993;Scapigliati et al, 1994) and we employ it here.…”

“…To reach this goal, much attention has been paid to the egg chorion due to its importance in spawning and embryo development. Although the protein content of the chorion of unfertilized eggs of D. labrax has already been ascertained (Scapigliati et al, 1994), data on chorion morphology are still needed.…”