Variation in reproductive photoresponsiveness in a wild population of meadow voles.
Variation in reproductive photoresponsiveness in a wild population of meadow voles.
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野生草甸田鼠种群生殖光响应性的变化。
DOI：
10.1095/biolreprod50.4.745
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发表时间：
1994
影响因子：
3.6
通讯作者：
Bellis,ED
中科院分区：
文献类型：
--
作者：
Kerbeshian,MC;Bronson,FH;Bellis,ED
在几种啮齿动物的实验室群体中，已经记录了生殖光反应的个体差异。当维持在短日照长度时，一些个体经历完全的性腺退化，另一些个体经历很少的性腺退化，还有一些个体表现出中等水平的反应性。在本研究中，实验室和实地研究相结合，探讨了这种变异对于控制草原田鼠（Microtus pennsylvanicus）野生种群季节性繁殖的潜在重要性。一个成年雄性的样本在夏天被困在宾夕法尼亚州中部，当时所有的雄性都处于繁殖状态。当在实验室中暴露于短日照时，这些雄性动物显示出上述反应性的整个变化范围，以及该处理诱导的体重减轻的相关变化。在冬至前被困在野外的雄性样本显示出与实验室中短日照的雄性样本相同的变异分布，因此，正如预期的那样，一些怀孕和哺乳期的雌性也在这个时候被困。42周的纵向研究表明，这种变化反映了睾丸在短时间暴露后的退化程度，而不是它们退化的速度。最后，对实验室出生的田鼠的研究表明，这种变化与年龄无关。总之，这些研究表明，以前只在实验室啮齿动物群体中观察到的生殖光反应的变化确实与理解野外生殖的季节性控制有关。
Individual variation in reproductive photoresponsiveness has been documented in laboratory colonies of several species of rodents. When maintained on short day lengths, some individuals experience complete gonadal regression, others undergo little if any gonadal regression, and still others show intermediate levels of responsiveness. In the present research, a combination of laboratory and field studies explored the potential importance of this kind of variation for the control of seasonal breeding in a wild population of meadow voles (Microtus pennsylvanicus). A sample of adult males was trapped in central Pennsylvania during the summer when all were in breeding condition. When exposed to short day lengths in the laboratory, these males showed the entire range of variation in responsiveness noted above and, correlatively, variation in the loss in body weight induced by this treatment. A sample of males trapped in the wild just before the winter solstice showed the same distribution of variation as did the males housed on short day lengths in the laboratory, and thus, as might be expected, a few pregnant and lactating females were also trapped at this time. Longitudinal studies over a 42-wk period revealed that the variation reflects the degree to which the testes regress in response to short-day exposure rather than the rate at which they regress. Finally, studies with laboratory-born voles demonstrated that the variation is independent of age. In total, these studies demonstrate that the variation in reproductive photoresponsiveness previously seen only in laboratory colonies of rodents indeed has relevance for understanding the seasonal control of reproduction in the wild.