Submitted to: Plant and Animal Genome VX Conference Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: January 5, 2005
Publication Date: January 15, 2005
Citation: Long, J.A., Zuelke, K.A. 2005. Addressing the biological challenges of germplasm preservation in poultry: new approaches for semen cryopreservation [abstract]. Plant and Animal Genome. 6:68.
A growing percentage (>37%) of the genetically diverse poultry stocks developed by academic researchers have disappeared or become 'at-risk' in recent years. The value of cryopreserved poultry semen for indefinite preservation of genetic material has long been recognized; however, the fertility rates from thawed poultry semen frozen with current cryogenic protocols are not adequate to recover poultry stocks. While it is evident that fertility rates for germ-line retrieval can be much lower (e.g. 20-40%) than that required for commercial production (>90%), cryopreserved sperm must retain sufficient functionality to avoid using excessively high insemination doses (>500 x 10e6 sperm) and frequent inseminations (3-4 times/wk) which could deplete the stockpile of banked semen. Key to the development of effective semen cryopreservation methodology is the systematic elucidation of the physiological events associated with the cryogenic cycle that result in compromised sperm function. Our experience with variable semen freezability from different poultry breeds, lines and strains indicates that multiple strategies will be required to fully develop cryopreservation protocols. The following provides an overview of our current strategies to address shortcomings in poultry cryopreservation technology: 1) optimizing current methods for immediate banking of 'at-risk' stocks (e.g. glycerol removal technique); 2) identifying sperm membrane/metabolism changes (e.g. glycoprotein complement, ATP production) occurring during the cryogenic cycle; and 3) using functional genomics/proteomics to assess the biology of the hen underlying sperm selection and storage mechanisms (e.g. SAGE analysis of sperm storage tubules).