Photoperiodic responses differ among inbred strains of golden hamsters (Mesocricetus auratus).
Photoperiodic responses differ among inbred strains of golden hamsters (Mesocricetus auratus).
复制标题
金仓鼠 (Mesocricetus auratus) 的近交系之间的光周期反应有所不同。
DOI：
10.1095/biolreprod49.3.496
复制
发表时间：
1993
影响因子：
3.6
通讯作者：
Turek,FW
中科院分区：
文献类型：
--
作者：
Vitaterna,MH;Turek,FW
自交系金仓鼠在恒定黑暗条件下运动活动昼夜节律的自由运行周期和运动活动夹带的相位角均存在差异。为了确定昼夜节律的差异是否影响光周期时间的测量，我们测量了4种不同自交系（MHA/SsLak、LSH/SsLak、BIO 1.5和BIO 87.20）和远交系（Lak:LVG(SYR)）维持睾丸功能的临界光周期以及反应率。每组仓鼠分别在5个不同的LD周期下维持12周。各组动物睾丸大小维持在14L:10D和12.5L:11.5D。在12周后维持睾丸大小的关键光周期内，观察到显著的应变差异；LSH/ sllak自交系在12L:12D光照下表现出完全的睾丸退化，而其他菌株在12L:12D光照下变化不大。所有暴露于11.5L:12.5D的实验组均有一定程度的睾丸退化，而所有暴露于6L:18D的实验组均有完全退化。在6L:18D和11.5L:12.5D下，不同组间睾丸退化率差异显著。不同菌株在关键光周期和睾丸退化率上的差异与已知菌株在携带或昼夜节律上的差异不相关，说明光周期反应的遗传差异与昼夜节律的遗传差异无关。此外，这些结果表明，对于任何给定基因型的金仓鼠，睾丸在抑制光周期暴露期间的退化率随白天长度的变化而变化，因此表观临界光周期可能取决于暴露于给定白天长度的长度。
Inbred strains of golden hamsters differ in both the free-running period of the circadian rhythm of locomotor activity in constant darkness, and in the phase angle of entrainment of activity to a 14L:10D cycle. To determine whether these differences in circadian entrainment affect photoperiodic time measurement, we measured the critical photoperiod for maintaining testicular function as well as the rate of response for four different inbred strains (MHA/SsLak, LSH/SsLak, BIO 1.5, and BIO 87.20) and an outbred stock (Lak:LVG(SYR)) of golden hamsters. Hamsters of each group were maintained for 12 wk under one of five different LD cycles. Animals of all groups maintained testis size in 14L:10D and 12.5L:11.5D. Significant strain differences were observed in the critical photoperiod for maintaining testis size after 12 wk; the LSH/SsLak inbred strain showed complete testicular regression during exposure to 12L:12D, while little change was observed in any of the other strains under this photoperiod. Some degree of testicular regression was observed in all groups exposed to 11.5L:12.5D, while complete regression was observed in all animals exposed to 6L:18D. The rate of testicular regression differed markedly between the different groups under both 6L:18D and 11.5L:12.5D. The differences in critical photoperiod and rate of testicular regression observed between the various strains could not be correlated with the known strain differences in entrainment or circadian period, indicating that genetic differences in photoperiodic response are not related to the genetic differences in circadian rhythmicity. Furthermore, these results demonstrate that for any given genotype of golden hamster, the rate of testicular regression during exposure to an inhibitory photoperiod varies as a function of the day length, and thus the apparent critical photoperiod may depend upon the length of exposure to a given day length.