この腕は、愛のためにある～ タコが「触って味わう」感覚で 交尾相手を見分ける仕組みを解明～

2026-04-03 沖縄科学技術大学院大学

オスの交接腕（青色）の吸盤内に存在する化学触覚受容体（白色）を可視化した顕微鏡画像。© Pablo Villar, Harvard University

＜関連情報＞

• https://www.oist.jp/ja/news-center/news/2026/4/3/these-arms-are-made-loving
• https://www.science.org/doi/10.1126/science.aec9652

タコの交尾のための感覚システム A sensory system for mating in octopus

Pablo S. Villar, Hao Jiang, Tatiana Shugaeva, Emma L. Berdan, […] , and Nicholas W. Bellono
Science  Published:2 Apr 2026
DOI:https://doi.org/10.1126/science.aec9652

Editor’s summary

Male octopuses use a specialized arm called the hectocotylus to navigate inside of the female mantle and toward the ovary to deposit spermatophores for fertilization. The mechanisms determining the success of this strategy have remained unknown. Villar et al. have now demonstrated that progesterone produced in female ovaries activates hectocotylus neural activity and autonomous movement and stimulates male mating search behavior (see the Perspective by Di Cosmo). Sensory cells in the hectocotylus expressing the receptor CRT1 are responsible for sensing progesterone. These results describe the molecular basis of a previously unrecognized sensory organ for mating in octopus and shed light on how sensory innovation determines reproductive success. —Mattia Maroso

Abstract

Sensory systems for mate recognition maintain species boundaries and influence diversification. Thus, uncovering how molecules and receptors evolve to mediate this critical function is essential to understanding biodiversity. Male octopuses use a specialized arm called the hectocotylus to identify females and navigate their internal organs to reach the oviduct and deliver sperm. Here, we discovered that the hectocotylus is a dual sensory and mating organ that uses contact-dependent chemosensation of progesterone, a conserved ovarian hormone. We identified chemotactile receptors for progesterone and resolved the structural basis for their evolution from ancestral neurotransmitter receptors and subsequent expansion and tuning across cephalopods. These findings reveal principles by which sensory innovations shape reproductive behavior and suggest mechanisms for how sensory evolution contributes to the diversification of life.