Purification and characterization of oocyte vitellin from Perinereis cultrifera (polychaete annelid)

Abstract

Vitellin was identified and purified from submature oocytes of Perinereis cultrfera by concanavalin-ASepharose and Ultrogel AcA 34 column chromatography. The yolk protein was defined as a glycolipoprotein with a relative molecular mass of' 380000. Upon dissociation by sodium dodecyl sulphate, vitellin was shown to release five polypeptide subunits which ranged in relative molecular mass from 98000 -16000. The purified vitellin was further characterized by amino acid analysis and its lipid and carbohydrate contents. The molecule contained about 5 % carbohydrate and 16'x lipid. Antiserum prepared against vitellin was shown to react with a component from the coelomic fluid of maturing females. Thus, it was suggested that in nereid annelids, considered phylogenetically and morphologically primitive, oocyte differentiation might depend upon the incorporation of a vitellogenin as in insects and many oviparous vertebrates.The sexuality of Nereids (Polychaeta worms) has been extensively studied. Many authors have demonstrated the existence of a brain neurohormone which inhibits oogenesis and somatic transformations of the epitoky [l -31. Studying the endocrinal determination of oogenesis, Durchon and Porchet [4] found a correlation between the brain hormonal production and the oocyte metabolism. During the juvenile phase characterized by an important production of brain hormone, yolk granules appear in the oocytic ooplasm (vitellogenesis) whereas at the time of genital submaturity, in absence of brain hormone, the oocytes produce cortical alveoli.While hormonal determination of oogenesis and cytology of the oocytes have been the object of several biological investigations [4 -81, relatively few biochemical studies have been carried out on the oocyte metabolism among the Nereidae. Concerning vitellogenesis, yolk synthesis has been shown to occur within the oocyte from small molecular weight precursors such as amino acids and monosaccharides (process termed autosynthesis) in Nel-eis divcwicolor, Perinereis cultr(fet,9, 101. However, Fischer [Ill, using Nereis virens, demonstrated the presence of a vitellin-like antigen in the coelomic fluid of mature females suggesting the heterosynthetic origin of the yolk. In Perinereis cultrifkra, immunological studies by Dhainaut et al. [I21 revealed identical antigens in the oocytes and coelomic fluid of females, but no significant evidence of an involvement of this material in yolk synthesis was obtained.Among annelids, reports on yolk protein remain limited to N . virens vitellin [13]. This protein, isolated by a method including DEAE-cellulose and phosphocellulose chromatography, has been characterized as a lipoglycoprotein of apparent Mr of 420000 and from its amino acid composition, appears to resemble insect vitellins. Apart from these gross features, Nereis vitellin remains poorly characterized. With interest in the hormonal control of vitellin synthesis as well as in its evolutionary relationship among annelids and other invertebrates, further studies of vitellins are requi...

Lipoprotein mediated lipid uptake in oocytes of polychaetes (Annelida)

“…This could explain the finding that neutral lipids are the main storage lipids in the oocyte of the polychaete Perinereis; these lipids account for the bulk of 20%-40% of the dry weight (Fontaine et al 1984a(Fontaine et al , 1984b, whereas phospholipids are the main lipids transported by the Nereis lipoprotein (Schenk et al 2006). However, as vitellogenin comprises 43% of the oocyte proteins (~0.1 μg/oocyte; Fischer and Schmitz 1981) and incorporates~16% lipids (Baert et al 1984), this would result in a contribution of 4%-8% to the total lipids of the oocyte, leaving 92%-96% of the total lipids to be derived from the lipoprotein and/or de novo synthesis. The uptake of free fatty acids either by direct import from the coelomic fluid or after hydrolysis of lipoprotein-associated lipids by a membrane-bound lipoprotein lipase, as proposed for the insect oocyte (see Ziegler and van Antwerpen 2006), cannot be ruled out.…”

“…The invertebrate vitellogenins described so far (mainly insect and crustacean vitellogenins) have lipid contents between 7% and 51% (Kunkel and Nordin 1985;Lee 1991). For the vitellin (the final storage form of vitellogenin in the oocyte) of two polychaetes, a lipid content of 16% and 50% has been reported (Baert et al 1984;Lee et al 2005). On the other hand, the non-sexspecific lipoproteins among the large lipid transfer proteins have also been shown to contribute to egg yolk, at least in crustacean (Lubzens et al 1997;Ravid et al 1999), insect Telfer et al 1991;Ximenes et al 2008), and chicken eggs (Steyrer et al 1990).…”

Yolk protein in leech

“…The total lipid content of vitellogenin (31.8% by mass) is close to that of crustacean lipovitellin (z 30% [38]) but higher than that of tick (~8 % [39]), insect (7-16% [3, 41) 14%) found for known insect vitellin [3]; it consists largely of mannose and glucosamine, as in other invertebrate yolk proteins [6,40]. Similarly a comparison of amino acid composition of T. tessulutum vitellin or its precursor with that of other invertebrate yolk proteins [3] shows no significant variation except for a lower amount of alanine in leech vitellin.…”

A 15000‐Mr protein proteolytically derived from vitellogenin within oocyte of Perinereis cultrifera (polychaete annelid)

“…iis mentioned in Materials and Methods. The lectin aflinity cliroin~itograpliic step was used to remove vitcllin from othcr oocytc proteins, the main yolk protein being adsorbed to concanavalin A a s dcscribed previously [20]. As revealed by SDS~poly~icrylaiiii~ic …”