Molecular speciation of fish sperm phospholipids: Large amounts of dipolyunsaturated phosphatidylserine

• Published in: Lipids
• Main Authors: Bell, M. V., Dick, J. R., Buda, Cs.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1997
• Subjects: Atlantic salmon; Salmo salar
• Online Access: http://dx.doi.org/10.1007/s11745-997-0140-y; https://onlinelibrary.wiley.com/doi/full/10.1007/s11745-997-0140-y

Abstract The molecular species compositions of the main diacyl phosphoglyceride classes and ether‐linked subclasses from sperm of three species of fish, sea bass Dicentrarchus labrax , Atlantic salmon Salmo salar and Chinook salmon Onchorhynchus tsawytscha , were determined. The phospholipids from sperm were highly unsaturated, dipolyunsaturated fatty acid (diPUFA) molecular species comprised 64.6 to 71.8% of phosphatidylserine (PS), 10.1 to 17.4% of phosphatidylethanolamine (PE), and 3.3 to 10.1% of phosphatidylcholine (PC). In sea bass sperm, di22∶6n‐3 phospholipid was the predominant diPUFA molecular species, but in both salmon species 22∶5n‐3/22∶6n‐3 was also a major constituent of PS. Phospholipids containing 22∶6n‐3 dominated in sea bass sperm with 16∶0/22∶6n‐3 as a major component of PC and PE, and 18∶0/22∶6n‐3 of PE and PS in addition to di22∶6n‐3 in the latter two classes. In contrast, both salmon species contained much more 20∶5n‐3 and less 22∶6n‐3 so that saturated/20∶5n‐3 and monounsaturated/20∶5n‐3 molecular species were more abundant than the corresponding molecules containing 22∶6n‐3. Ether‐linked lipids comprised 11.3–36.3% of choline and ethanolamine phosphoglycerides in each fish species. Molecular species containing 22∶6n‐3 were the major components of 1‐ O ‐alkyl‐2‐acyl‐glycerophosphocholine, especially 16∶0a/22∶6n‐3 in sea bass and 18∶1a/∶6n‐3 in the two salmon species, while in 1‐ O ‐alk‐1′‐enyl‐2‐acyl‐glycerophosphoethanolamine, 16∶0a/22∶6n‐3 was the major component in both salmon and 18∶0a/22∶6n‐3 in sea bass with 18∶1a/22∶6n‐3 abundant in all three species. In Atlantic salmon 1‐ O ‐alkyl‐2‐acylglycerophosphoethanolamine comprised 24.6% of ethanolamine glycerophospholipids which were predominantly 16∶0a/22∶6n‐3 and 18∶1a/22∶6n‐3. Phosphatidylinositol from sperm was dominated by stearoyl/C 20 PUFA molecular species, in sea bass overwhelmingly 18∶0/20∶4n‐6, while in both salmon species 18∶0/20∶4n‐6 and 18∶0/20∶5n‐3 were equally abundant.