Li Xixuan, Li Ning, Yao Dandan, Liu Yu, Song Ying, Wang Dawei, Feng Zhiyong, Liu Xiaohui
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou, Guangdong, China.
Integr Zool. 2025 Jul;20(4):817-835. doi: 10.1111/1749-4877.12913. Epub 2024 Oct 21.
How organisms respond to complex environments is one of the unsolved problems in ecology. Life history patterns of a species provide essential information on how different populations may respond and adapt to environmental changes. Compared to typical seasonal breeders, which have limited distributions, the worldwide distribution of brown rats (Rattus norvegicus) across highly complex and divergent habitats suggests they exhibit exceptional adaptiveness. However, the difference in physiological mechanisms by which brown rats respond and adapt to markedly different environments is seldom investigated. Here, we reveal a significant divergence in reproductive seasonality and environmental responses between two brown rat subspecies: one subspecies, R. n. caraco, lives in the temperate zone, and another subspecies, R. n. norvegicus, lives in the subtropical region. Although R. n. caraco displayed a significantly higher reproductive seasonality than R. n. norvegicus, both subspecies adapted to sub-optimal breeding conditions mainly by regulating the seminal vesicle rather than testis development. Especially in responding to severe winter conditions in high-latitude regions, bodyweight-dependent recovery of testicular development in adults enables R. n. caraco to initiate reproduction more rapidly when conditions are suited. These findings elucidate a regulatory process of how brown rats live as opportunistic breeders by benefiting from enhanced semen production.
生物体如何应对复杂环境是生态学中尚未解决的问题之一。一个物种的生活史模式提供了关于不同种群如何应对和适应环境变化的重要信息。与分布有限的典型季节性繁殖者相比，褐家鼠（Rattus norvegicus）在全球高度复杂和多样的栖息地中的分布表明它们具有非凡的适应性。然而，褐家鼠应对和适应明显不同环境的生理机制差异很少被研究。在这里，我们揭示了两种褐家鼠亚种在繁殖季节性和环境反应方面存在显著差异：一个亚种，R. n. caraco，生活在温带，另一个亚种，R. n. norvegicus，生活在亚热带地区。虽然R. n. caraco的繁殖季节性明显高于R. n. norvegicus，但两个亚种主要通过调节精囊而不是睾丸发育来适应次优繁殖条件。特别是在应对高纬度地区的严冬条件时，成年R. n. caraco睾丸发育的体重依赖性恢复使其能够在条件适宜时更快地开始繁殖。这些发现阐明了褐家鼠如何通过增加精液产量而成为机会主义繁殖者的调节过程。
