アリゾナ大学主導の新しい研究によると、エストラジオールの増加は、キツネザルが父親になるための準備に役立つ可能性があるそうです。 The increase in estradiol may help prepare the lemurs for fatherhood, according to new University of Arizona-led research.
2023-02-21 アリゾナ大学
◆アカハラギツネザルは、マダガスカル東部の熱帯雨林に生息する一夫一婦制の樹上性霊長類です。家族単位で一緒に暮らし、子どもは3〜4歳くらいで独立します。
◆エストラジオールはエストロゲンというステロイドホルモンで、哺乳類では母親の感受性と反応性を高めるとされている主要な女性ホルモンである。
◆このホルモンの急増は、主に妊娠第3期に起こる。キツネザルの典型的な妊娠期間は約126日、つまり4カ月強である。アリゾナ大学の人類学准教授であるステイシー・テコットが主導して雑誌「Hormones and Behavior」に発表した新しい研究によれば、その最後の3学期に、男性はエストラジオールの4倍の増加を見ることができます。
<関連情報>
- https://news.arizona.edu/story/expectant-lemur-dads-see-hormonal-changes-response-pregnant-mates-poop-shows
- https://www.sciencedirect.com/science/article/abs/pii/S0018506X23000223?via%3Dihub
アカハラギツネのオス、Eulemur rubriventerにおけるエストラジオールと父性ケアの機能的関係 Functional relationships between estradiol and paternal care in male red-bellied lemurs, Eulemur rubriventer
Stacey R. Tecot , Madalena Birr, Juliana Dixon, Jean Pierre Lahitsara, Dominique Razafindraibe, Soafaniry Razanajatovo, Alicia S. Arroyo, Aimé Victor Tombotiana, Jean Baptiste Velontsara, Andrea L. Baden
Hormones and Behavior Available online: 10 February 2023
DOI:https://doi.org/10.1016/j.yhbeh.2023.105324
Highlights
- •Expectant fathers’ estradiol metabolites elevated fourfold in the third trimester.
- •Expectant fathers’ estradiol levels did not predict future paternal care.
- •Estradiol metabolite levels fluctuated during infant care.
- •Estradiol profiles in new fathers were not associated with paternal care.
Abstract
Fathers contribute substantially to infant care, yet the mechanisms facilitating paternal bonding and interactions with infants are not as well understood as they are in mothers. Several hormonal changes occur as males transition into parenthood, first in response to a partner’s pregnancy, and next in response to interacting with the newborn. These changes may prepare fathers for parenting and help facilitate and maintain paternal care. Experimental studies with monkeys and rodents suggest that paternal care requires elevated estradiol levels, which increase when a male’s partner is pregnant and are higher in fathers than non-fathers, but its role in the expression of paternal behaviors throughout infant development is unknown. To assess estradiol’s role in paternal care, we analyzed the relationship between paternal estradiol metabolites and 1) offspring age, and 2) paternal care behavior (holding, carrying, huddling, playing, grooming), in wild, red-bellied lemurs (Eulemur rubriventer). We collected 146 fecal samples and 1597 h of behavioral data on 10 adult males who had newborn infants during the study. Estradiol metabolites increased four-fold in expectant males, and in new fathers they fluctuated and gradually decreased with time. Infant age, not paternal behavior, best predicted hormone levels in new fathers. These results suggest that hormonal changes occur in expectant males with facultative paternal care, but they do not support the hypothesis that estradiol is directly associated with the day-to-day expression of paternal care. Future research should explore estradiol’s role in facilitating behaviors, including infant-directed attention and responsiveness, or preparing fathers for infant care generally.
