Smale L, Nelson R J, Zucker I
Department of Psychology, University of California, Berkeley 94720.
J Reprod Fertil. 1988 May;83(1):99-106. doi: 10.1530/jrf.0.0830099.
Short daylengths did not affect testes weight or spermatogenic index in male voles or uterine weight in female voles. Short daylengths did stimulate the growth of a winter pelage in both sexes; short-day voles had longer underhairs and guard hairs and a thicker, more dense pelage than did long-day voles. Plasma prolactin concentrations were five times higher in long-day than in short-day females and 25% higher in long-day males than in short-day males. The effect of short daylength on pelage was prevented by pinealectomy. We suggest that the growth of a winter coat is an obligate adaptation for winter survival, stimulated by exposure to short daylengths, but that changes in breeding activity are facultative and dependent to a greater extent on other cues for seasonal synchronization.
短日照对雄性田鼠的睾丸重量或生精指数以及雌性田鼠的子宫重量均无影响。短日照确实会刺激两性长出冬季皮毛；短日照田鼠的绒毛和针毛比长日照田鼠的更长，皮毛更厚且更浓密。长日照雌性田鼠的血浆催乳素浓度是短日照雌性田鼠的五倍，长日照雄性田鼠的血浆催乳素浓度比短日照雄性田鼠高25%。松果体切除可阻止短日照对皮毛的影响。我们认为，冬季皮毛的生长是冬季生存的一种必要适应，由短日照刺激引发，但繁殖活动的变化是可调节的，在更大程度上依赖于其他季节性同步线索。
