FATTY-ACID COMPOSITION OF VITELLOGENIN FROM 4 TELEOST SPECIES

The fatty acid compositions of vitellogenin and liver from cod (Gadus morhua), rainbow trout (Oncorhynchus mykiss), turbot (Scophthalmus max imus) and wolffish (Anarhichas lupus) were determined. Vitellogenin wa s isolated from plasma of estradiol-17 beta-treated fish by precipitat ion with EDTA-Mg2+ and distilled water or by high-performance ion-exch ange chromatography. In all investigated species, vitellogenin contain ed 16-18% (w/w) lipid, in which polyunsaturated fatty acids, predomina ntly 20:5 (n-3) and 22:6 (n-3), comprised about 50% of the total fatty acids. The proportions of saturated, monounsaturated, polyunsaturated and (n-3) fatty acids in vitellogenin of the different species were g enerally similar, although the relative content of specific fatty acid s was distinctive for each species. The distribution of fatty acids in total lipids of vitellogenin was highly consistent among individual f emales of each species. In contrast, liver fatty acid composition vari ed considerably, both within and between species. Altogether, the diff erences in the fatty acid composition of vitellogenin and liver from e ach species indicate that a specific selection of fatty acids occurs d uring the lipidation of vitellogenin.