?Fine feathers make fine birds?-The mammalian sperm plasma membrane lipid composition and effects on assisted reproduction

The sperm plasma membrane is important in modulating many sperm functions. The sperm membrane is composed of a complex mixture of lipids including phospholipids, glycolipids and sterols. There are differences of sperm membrane composition among mammalian species with two groups differing in the most abundant polyunsaturated fatty acid (PUFA), either docosa-hexaenoic (omega-3 PUFA) or docosapentaenoic acid (omega-6 PUFA). During testicular and epididymal maturation, composition of the sperm plasma membrane evolves with spermatozoa gaining the capacity for fertilization. The importance of fatty acid metabolism for complete spermatogenesis has been elucidated using gene knockout mice. During epididymal transit cholesterol content decreases and PUFA content increases, conferring more fluidity properties to the sperm mem-brane. The relatively lesser content of antioxidant enzymes and the relatively larger content of PUFA make the spermatozoa particularly susceptible to lipid peroxidation during sperm preser-vation. In numerous studies, there was adding of PUFA and antioxidants to the diet of animals or to semen extenders with the aim to improve sperm membrane integrity. This review highlights the current knowledge on the sperm membrane composition and effects on sperm function in mammalian domestic animals.

Automated summary

The lipid composition of the sperm plasma membrane plays a crucial role in sperm function, with changes in cholesterol and PUFA levels affecting sperm motility and fertilization ability. Adding PUFA and antioxidants can improve the integrity of the sperm membrane.