Mechanism of sperm storage in the female reproductive tract in birds

2014 Fiscal Year Final Research Report

• Project/Area Number: 24380153
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Applied animal science
• Research Institution: Shizuoka University
• Principal Investigator: SASANAMI Tomohiro 静岡大学, (連合)農学研究科(研究院), 准教授 (80322139)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 精子貯蔵管 / 輸卵管 / 精子貯蔵 / 乳酸 / ウズラ

Outline of Final Research Achievements

In several vertebrate groups, post-copulatory sperm viability is prolonged by their storage in specialized organs within the female reproductive tract. In birds, ejaculated sperm can be stored in a quiescent stage within oviductal sperm storage tubules (SSTs), thereby preventing the loss of fertility for up to 15 weeks; however, the mechanism by which once-activated spermatozoa are rendered quiescent within SSTs remains a mystery. Here, we show that quail SSTs maintain a hypoxic niche and secrete lactic acid. Sperm immobility is induced by lactic acid through cytoplasmic acidification and flagellar dynein ATPase inactivation. The assertion that hypoxia played a role in the process of sperm storage was further supported by improved morphological preservation of ejaculated spermatozoa under hypoxic conditions at body temperature. Our results open up new opportunity for technological improvement in prolonging sperm longevity at ambient or body temperature.

Free Research Field

繁殖生物学