Data from: Dynamic expressions of hypothalamic genes regulate seasonal breeding in a natural rodent population

Seasonal breeding is a universal reproductive strategy in many animals.
Hypothalamic genes, especially type 2 and 3 iodothyronine deiodinases
(Dio2/3), RFamide-related peptide 3 (Rfrp-3), kisspeptin (Kiss-1), and
gonadotropin-releasing hormone (GnRH), are involved in a photoperiodic
pathway that encodes seasonal signals from day length in many vertebrate
species. However, the seasonal expression patterns of these genes in wild
mammals are less studied. Here, we present a four-year field investigation
to reveal seasonal rhythm and age-dependent reproductive activity in male
Brandt’s voles (Lasiopodomys brandtii) and to detect relationships among
seasonal expression profiles of hypothalamic genes, testicular activity,
age, and annual day length. From breeding season (April) to non-breeding
season (October), adult male voles displayed a synchronous peak in gonadal
activity with annual day length around summer solstice, which was jointly
caused by age structure shifts and age-dependent gonadal development
patterns. Overwintered males maintained reproductive activity until late
in the breeding season, whereas most newborn males terminated gonadal
development completely, except for a minority of males born early in
spring. Consistently, the synchronous and opposite expression profiles of
Dio2/3 suggest their central function to decode photoperiodic signals and
to predict the onset of the non-breeding season. Moreover, changes in
Dio2/3 signals may guide the actions of Kiss-1 and Rfrp-3 to regulate the
age-dependent divergence of reproductive strategy in wild Brandt’s vole.
Our results provide evidence on how hypothalamic photoperiod genes
regulate seasonal breeding in a natural rodent population.

季节性繁殖是多数动物普遍存在的繁殖策略。下丘脑基因，尤其是2型、3型碘化甲状腺氨酸脱碘酶（Dio2/3）、RF酰胺相关肽3（Rfrp-3）、吻肽（kisspeptin，Kiss-1）以及促性腺激素释放激素（GnRH），参与了众多脊椎动物类群中编码基于日照时长的季节性信号的光周期通路。然而，目前针对野生哺乳动物中这些基因的季节性表达模式的研究尚少。本研究通过为期四年的野外调查，揭示了雄性布氏田鼠（Lasiopodomys brandtii）的季节性节律与年龄依赖性繁殖活动，并探究了下丘脑基因季节性表达谱、睾丸活动、年龄与年度日照时长之间的关联。从繁殖季（4月）至非繁殖季（10月），成年雄性田鼠的性腺活动与年度日照时长同步出现峰值，该峰值出现在夏至前后，这一现象由年龄结构变化与年龄依赖性性腺发育模式共同导致。越冬雄鼠的繁殖活动可持续至繁殖季末期，而绝大多数新生雄鼠则完全终止性腺发育，仅少数春季早期出生的雄鼠例外。与之相符的是，Dio2/3同步且呈反向的表达谱表明，二者在解码光周期信号、预测非繁殖季起始方面发挥核心功能。此外，Dio2/3的信号变化可能通过调控Kiss-1与Rfrp-3的表达，进而调节野生布氏田鼠年龄依赖性的繁殖策略分化。本研究结果阐明了下丘脑光周期基因如何调控自然啮齿动物种群的季节性繁殖机制。