A new framework for parental care investigated through the endocrine mechanismism of infanticide

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H02569
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 45040:Ecology and environment-related
• Research Institution: Nagasaki University
• Principal Investigator: Takegaki Takeshi 長崎大学, 水産・環境科学総合研究科(水産), 准教授 (50363479)
• Co-Investigator(Kenkyū-buntansha): 阿見彌 典子 北里大学, 海洋生命科学部, 講師 (20588503) ; 福田 和也 北里大学, 海洋生命科学部, 助教 (20882616) ; 菅 向志郎 長崎大学, 水産・環境科学総合研究科(水産), 教授 (60569185) ; 天谷 貴史 長崎大学, 海洋未来イノベーション機構, 助教 (70899054)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 親による子の保護 / 子殺し / 進化 / 行動生態 / 内分泌 / 魚類 / 脳

Outline of Final Research Achievements

We investigated the mechanism by which total filial cannibalism in the male Rhabdoblennius nitidus occurs as a synergistic effect of parental care and feeding behaviors regulated by prolactin-releasing peptide (PrRP). (1) Comparison of neural activity in 25 brain regions in cannibalising, egg-tending, and feeding males suggested that total filial cannibalism involves specifically active higher-order central regions and is expressed in these regions and in regions that regulate feeding. (2) Egg-rearing seawater was exposed to the olfactory epithelium of males, suggesting that males may recognize the presence of eggs by pheromones. (3) Transcriptome analysis of male whole brains revealed several genes related to feeding regulation that were suggested to be related to the expression of cannibalism.

Free Research Field

行動生態学

Academic Significance and Societal Importance of the Research Achievements

親が保護中の子を食べる一見非適応的な現象は、親が割の合わない保護を打ち切って繁殖をやり直す適応戦略とされてきたが、申請者らはロウソクギンポ雄の全卵食が栄養利益を期待して保護卵を「食べる」のではなく、自身の求愛を促進する性ホルモン分泌を促すために卵の存在を消す「子殺し」であることを証明した。子を保護中の親が次の瞬間には子を食べ始めるドラスティックな転換機構の解明は、子殺し発現だけでなく子の保護の発現・維持機構の理解にも繋がると考えられる。