Lipid Deposition in Oocytes of Teleost Fish During Secondary Oocyte Growth

Abstract

Research pertaining to the deposition of lipids into the maturing oocytes of teleost fish has progressed significantly since the review by Wiegand (1996). Studies on broodstock diets have elucidated the importance of incorporating n-3 and n-6 highly unsaturated fatty acids (HUFAs) into diets at the proper levels and ratios for optimal egg viability and survival of progeny. The vitellogenin receptor, VgR, has been well classified in some teleost species and is now suspected to be evolutionarily linked to the LR8(-) receptor in birds and mammals. The expression of a somatic lipoprotein receptor has been observed in the maturing oocytes of teleost fish. Multiple forms of vitellogenin have been discovered in a number of teleost species. There is also a growing amount of evidence suggesting other plasma lipoproteins may play a major role in the deposition of lipids for some species. Finally, there is additional evidence that vitellogenic oocytes are capable of de novo synthesis of lipids, which provides insight on how the oocyte lipid class composition is regulated within a species. This review attempts to summarize the current knowledge related to the deposition of lipids into the oocytes of teleost fish during oogenesis and collates results from recent studies in this area.

Keywords:

• lipid transport
• vitellogenesis
• lipoproteins
• vitellogenin receptor
• essential fatty acids
• de novo lipid biosynthesis