Submitted to: Plant and Animal Genome Conference
Publication Type: Abstract Only
Publication Acceptance Date: December 30, 2009
Publication Date: January 8, 2010
Citation: Long, J.A. 2010. Avian Sperm Cryopreservation: Shifting The Paradigm From Empirical Approaches To Physiological Solutions. Plant and Animal Genome Conference XVIII, W495.
Interpretive Summary: Despite decades of empirical research, poultry semen cryopreservation methods are not reliable for use in preservation of genetic stocks. We have conducted systematic experiments to understand how and why poultry sperm lose functional competence after cryopreservation, including evaluation of carbohydrates, lipids and proteins. First, we have shown that the glycocalyx, the carbohydrate-rich zone on the sperm surface, is altered by the cryogenic cycle. Sialic acid, known to be critical for sperm transport in the female reproductive tract, was reduced after cryopreservation. Further, we have shown that sperm cells can incorporate exogenous sialic acid, suggesting a strategy for sperm freezing protocols. Sperm lipid ratios, particularly phosphotidylcholine, also are altered during cold storage and impact the success of cryopreservation through changing membrane fluidity. We have shown that exogenous lipids can circumvent the loss of phospholipids during cryopreservation. We also have identified a mechanism to alter membrane lipid composition by altering the type of fat in the diet. Finally, we have conducted the first proteomic analysis of poultry spermatozoa and have identified proteins associated with the acrosome (pro-acrosin), mitochondria (enolase I, voltage-dependent anion channel 2), and flagellum (capping protein, tektins 1-5). Several chaperone (heat shock protein 70) and calcium-binding (EF-hand protein) proteins also were identified. Three proteins not previously found in sperm were identified: dihydropyrimidinase, mitofilin and mitochondrial tri-functional protein. We now are evaluating the proteomic profile of frozen/thawed sperm to uncover the impact of cryopreservation on sperm proteins. Taken together, the data suggests innovative strategies for developing reliable poultry sperm cryopreservation methods.