The Photorefractory Period of the House Finch
The Photorefractory Period of the House Finch
复制标题
家雀的光不应期
作者：
W. Hamner
以家雀为研究对象，研究了家雀睾丸退化和光反射的时间机制。睾丸消退在八月完成，随后是一个半月的光不应期。完全恢复光敏是一个个别的、渐进的过程，需要几个月的时间。下丘脑正中隆起可见染色的神经分泌似乎与光难性无关。脂质集中在退化的睾丸中，到九月中旬消失，然后间质染色为脂肪。配子体发生的变化在光难耐性期间不会发生。睾丸退化可以随意诱导，而光分裂性并不是睾丸退化的必然伴随物。中间六睾丸的退化似乎与促性腺激素释放不足有关；中等大小睾丸的生长可能是每天递增的。完全发育的睾丸退化可以自发发生；在连续光照和LD 18:6团的条件下，可自发消退；这些方案延长了光耐火性。注射睾酮不会导致退化，但会促进睾丸生长。催乳素既不影响睾丸的生长也不影响睾丸的退化，但会导致身体增肥。经前综合症和睾酮不会加速难治性终止。虽然两者都促进早熟生长，但睾丸在激素消退后会退化。短日（ld6∶18）和长日（ld10∶14、ld12∶12、ld14∶10）都同样终止光致耐火度。昼夜节律可能导致光反射性的终止。列举了以前的光难降解控制假设，考虑了可能的定时机制类型，并提出了一个新的假设，进行了测试和讨论。开发了一个与所有田间和实验室观察相一致的整个年周期的育种控制模型。
The timing mechanisms of testicular regression and photorefgractoriness were investigated with the Houswe Finch. Testicular regression is completed by August and is followed by a month and a half photorefractory period. Resumption of complete photosensitivity is an indicidual, gradual precess of several months. Stainable neurosecretion in the median eminence of the hypothalamus appears unrelated to photorefractoriness. Lipids concentrate in regressing testes, disappear by mid—September and then the interstitium stains for fats. Changes in gametogenesis do not occur during photorefractoriness. Testicular regression can be induced at will, and photofractoriness is not a necessary concomitant thereof. Regression of intermediate sixed testes appears related to a lack of gonadotropic hormone release; growth of intermediate sized testes is probably additive on a daily basis. Regression of fully developed testes can occur spontaneously; then regression is followed by photorefractoriness Spontaneous regression can occur under continuous illumination and LD 18:6 regiments; photorefractoriness is porlonged by these regimens. testosterone injections do not induce regression, but enhance testiculargrowth. Prolactin does not affect either growth or regression of the testes, but causes bodily fattening. PMS and testosterone do not hasten refractory termination. Although both promote precocious growth, the testes regress upon hormone withdrawal. Short days (LD 6:18) and long days (LD 10:14, LD 12:12, LD 14:10) all terminate photorefractoriness equally. A circadian rhythm may contribute to termination of photorefgractoriness. Previous photorefractory control hypothesis are enumerated, types of possible timing machanisms are considered, and a new hypothesis proposed, tested, and discussed. A model of breeding control for the entire annual cycle is developed, consistent with all field and laboratory observations.