Intracellular signal transduction mechanism of regulating bovine sperm thermotaxis

2018 Fiscal Year Final Research Report

• Project/Area Number: 15K07690
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Animal production science
• Research Institution: Shinshu University
• Principal Investigator: Hamano Koh-ichi 信州大学, 学術研究院農学系, 教授 (70303443)
• Project Period (FY): 2015-10-21 – 2019-03-31
• Keywords: ウシ精子 / 走温性 / 温度勾配 / 制御因子 / 発現機構 / 運動解析

Outline of Final Research Achievements

This study was basic study to apply the new evaluating system of the sperm using thermotaxis in the livestock raising settings and obtained the following results. We confirmed the initiating temperature of thermotaxis expression of the bull sperm and optimal temperature gradient for thermotaxis. Both of calcium channel inhibition by Verapamil, SKF, Ruthenium red, RN-1734 and inhibition of Calaxin, calmodulin inhibited thermotaxis, and curvilinear velocity and flagellar amplitude decreased as compared with thermotaxis. GSK1016790A of the TRP channel agonist promoted thermotaxis. We confirmed increase of the calcium concentration of the thermotaxis expressed sperm, reversible change by temperature lifting and lowering. ddA, 2CE of the tmAC, sAC inhibitor and the hydroxylamine of the opsin inhibitor inhibited the thermotaxis of the bull sperm. We confirmed thermotaxis expression before and after sperm capacitation. The viscous medium inhibited the thermotaxis of capacitated sperm.

Free Research Field

家畜繁殖

Academic Significance and Societal Importance of the Research Achievements

本研究ではウシ精子の走温性における発現機構とカルシウムの動態、作用機構を調べた。走温性発現精子のカルシウムチャネル、カルシウム結合タンパクの解析から、温度勾配における走温性の発現、走温性の調節における特定のカルシウムチャネル、複数のカルシウム結合タンパクの関与が明らかになり、温度勾配における精子の移動、温度変化による精子の頭部および尾部の運動調節機構の一部が解明され、受精における精子の運動機能が解明される。走温性を指標にした客観的で正確な精子の受精能の解析、雄ウシの繁殖能力の評価が可能になり、繁殖性の高い雄ウシが選抜され、人工授精後の雌ウシの受胎率が改善し、効率的にウシを増産できる。