Chaturvedi C M, Bhatt R, Phillips D
Department of Zoology, Banaras Hindu University, Varanasi, India.
Indian J Exp Biol. 1993 May;31(5):417-21.
Cloacal gland (an androgen dependent sex accessory) of Japanese quail exhibits full breeding condition as long as these were maintained under long days (LD 16:8). When shifted to short daylength (LD 6:18), scotosensitivity (cloacal gland regression) was observed up to 5 weeks, followed by scotorefractoriness (cloacal gland development). There was a regression in cloacal gland volume of the birds when shifted to intermediate daylength (LD 13.5:10.5 and 13:11) after 12 weeks of exposure to long days (relative refractoriness) but no regression when shifted to relatively short days (< 14 hr) after 3 weeks of exposure to long daylength. Birds maintained under constant short photoperiod (LD 6:18) exhibited cyclicity. Shift experiments (quail reared and maintained under continuous light; LL, were shifted to LD 16:8, 13:11 and 8:16, similarly quail maintained under LD 16:8 were shifted to rest three photoperiods and so on) made to compare the cloacal gland responses indicated that if the difference between two photoperiods (previous and shifted one) was more the percentage of difference in cloacal gland response was also high. Short daylength (LD 8:16) was always gonadoinhibitory for the quail previously exposed to any daylength (13L, 16L or 24L) and 16L and 24L were always stimulatory for the quail previously exposed to other daylength (8L, 13L, 16L). But, when the birds were shifted to 13L, photoresponses cannot be generalized and it depends on the photoperiod to which quail were exposed previously (i.e. photoperiodic history).
日本鹌鹑的泄殖腔腺（一种雄激素依赖的性附属器官）只要饲养在长日照（16小时光照：8小时黑暗，即LD 16:8）条件下，就会呈现出完全的繁殖状态。当转为短日照（6小时光照：18小时黑暗，即LD 6:18）时，在长达5周的时间内可观察到暗敏感性（泄殖腔腺退化），随后是暗不应性（泄殖腔腺发育）。在长日照暴露12周后转为中间日照时长（13.5小时光照：10.5小时黑暗，即LD 13.5:10.5和13小时光照：11小时黑暗，即LD 13:11）时，鹌鹑的泄殖腔腺体积会出现退化（相对不应性），但在长日照暴露3周后转为相对短日照（<14小时）时则不会出现退化。饲养在恒定短光周期（LD 6:18）下的鹌鹑表现出周期性。为比较泄殖腔腺反应而进行的转换实验（饲养并维持在持续光照，即LL条件下的鹌鹑，转换到LD 16:8、13:11和8:16；同样，饲养在LD 16:8条件下的鹌鹑转换到另外三个光周期等等）表明，如果两个光周期（之前的和转换后的）之间的差异越大，泄殖腔腺反应的差异百分比也越高。短日照时长（LD 8:16）对之前暴露于任何日照时长（13L、16L或24L）下的鹌鹑始终具有性腺抑制作用，而16L和24L对之前暴露于其他日照时长（8L、13L、16L）下的鹌鹑始终具有刺激作用。但是，当鹌鹑转换到13L时，光反应无法一概而论，这取决于鹌鹑之前所暴露的光周期（即光周期历史）。
