Sex-specific endocrine regulation of seasonal aggression in Siberian hamsters

Coordinating physiological and behavioural processes across the annual cycle is essential in enabling individuals to maximize fitness. While the mechanisms underlying seasonal reproduction and its associated behaviours are well-characterized, fewer studies have examined the hormonal basis of non-reproductive social behaviours (e.g., aggression) on a seasonal timescale. Our previous work suggests that the pineal hormone melatonin facilitates a ‘seasonal switch’ in neuroendocrine regulation of aggression in male and female Siberian hamsters (Phodopus sungorus), specifically by acting on the adrenal glands to increase the production of the androgen dehydroepiandrosterone (DHEA) during the short-day (SD) photoperiods of the non-breeding season. Here, we provide evidence that the activity of 3β-hydroxysteroid dehydrogenase/∆5-∆4 isomerase (3β-HSD), a key enzyme within the steroidogenic pathway that mediates DHEA synthesis and metabolism, varies in a sex-specific and melatonin-dependent manne...协调全年周期内的生理与行为过程，是个体实现适合度最大化的必要前提。尽管季节性繁殖及其相关行为的调控机制已得到充分阐释，但针对非繁殖社交行为（如攻击行为）的季节性激素调控基础的研究仍相对较少。我们此前的研究表明，松果体激素褪黑素（melatonin）可介导雌雄西伯利亚仓鼠（Phodopus sungorus）攻击行为神经内分泌调控的‘季节性转换’，具体机制为在非繁殖季节的短日照（SD）光周期下，通过作用于肾上腺以增加雄激素脱氢表雄酮（dehydroepiandrosterone, DHEA）的合成。本研究证实，介导脱氢表雄酮合成与代谢的类固醇生成通路关键酶3β-羟类固醇脱氢酶/Δ5-Δ4异构酶（3β-hydroxysteroid dehydrogenase/∆5-∆4 isomerase, 3β-HSD）的活性，呈现出性别特异性且依赖于褪黑素的变化模式……