Molecular mechanism regulating expression of estrous behavior in ruminants

2020 Fiscal Year Final Research Report

• Project/Area Number: 16H05014
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Animal production science
• Research Institution: Nagoya University
• Principal Investigator: Ohkura Satoshi 名古屋大学, 生命農学研究科, 教授 (20263163)
• Project Period (FY): 2016-04-01 – 2020-03-31
• Keywords: 応用動物 / 行動学 / 獣医学 / 畜産学 / 神経科学 / ヤギ / エストロジェン / 発情行動

Outline of Final Research Achievements

The present study aimed to elucidate the neural mechanisms controlling estrus behavior in ruminants using genetically modified goats that can conditionally knock out estrogen receptor (ER) expression, which plays a primary role in inducing estrus behavior. First, we constructed a model that induced estrus behavior by hormone treatment and found that the increase in the behavioral activity associated with estrus was a quantitative parameter to evaluate the estrus behavior in goats. Second, we identified the nucleotide sequence and deduced amino acid sequence of the goat ER gene mRNA, and optimized the goat genetic engineering technology to implement genome editing technology by “gene editing by electroporation of Cas9 protein (GEEP)” method in 1-cell stage embryo. Third, we developed a method to implant a microinjection cannula stereotaxically in the brain region where goat ER is highly expressed.

Free Research Field

家畜繁殖学

Academic Significance and Societal Importance of the Research Achievements

本研究において確立した、発情に伴う行動量増加を指標とした発情行動の定量的評価系は、発情行動発現のタイミングを正確に測ることが可能となる点で、反芻動物の発情行動を制御する神経機構の解明に大きく寄与する実験モデル系となる。また、本研究により確立したヤギの遺伝子工学基盤（過排卵処置、卵管内受精卵（1細胞期胚）採取法、GEEP法によるゲノム編集胚の作出など）は、ヤギをモデルとしたゲノム編集技術の確立に寄与し、遺伝子改変技術の対象動物としてのヤギの有用性を飛躍的に高めることができる。