Karakaş Alper, Gündüz Bülent
Department of Biology, Faculty of Arts and Sciences, Abant Izzet Baysal University, 14280 Bolu-Turkey.
Zoolog Sci. 2002 Feb;19(2):233-9. doi: 10.2108/zsj.19.233.
The role of photoperiod in adult testicular maintenance and body weight and juvenile development was assessed in male Mongolian gerbils (Meriones unguiculatus). Gerbils were raised on a 14L (14 hr of light) photoperiod. In the first study, adult gerbils with functional testes were transferred to thirteen different photoperiods (0L, 2L, 4L, 6L, 8L, 10L, 12L, 14L, 16L, 18L, 20L, 22L, or 24L) and body weights and testicular size were measured every week for 10 weeks. Body weights were similar in all groups. Testicular regression had occurred in animals housed on 0L, 2L, 4L, 6L, 8L, and 24L by week 10. In the second study, 14L-born prepubertal gerbils were transferred to thirteen different photoperiods as in the first study. Body weights and testicular development were examined for 10 weeks. At the end of 10 weeks the body weights of animals in all groups except 24L were similar to those of adults. Animals in 24L had a lower body weight gain. Exposure to 0L, 2L, and 24L inhibited testicular development and testes weights were significantly different from those of the other groups. These results demonstrate that maintenance of body weight in adult gerbils appears to be independent of photoperiodic signal. Exposure to very long (24L) and short photoperiods (< 10 hr) causes testicular regression in adult gerbils. Moreover, different photoperiods experienced in early life can influence prepubertal testis growth and body weight gain.
研究人员评估了光周期对雄性蒙古沙鼠（长爪沙鼠）成年期睾丸维持、体重及幼年期发育的作用。沙鼠饲养于14小时光照（14L）的光周期环境中。在第一项研究中，将具有功能性睾丸的成年沙鼠转移至十三种不同的光周期环境（0L、2L、4L、6L、8L、10L、12L、14L、16L、18L、20L、22L或24L），并在10周内每周测量体重和睾丸大小。所有组的体重相似。到第10周时，饲养于0L、2L、4L、6L、8L和24L光周期环境中的动物出现了睾丸退化。在第二项研究中，将出生于14L光周期环境的青春期前沙鼠按照第一项研究的方法转移至十三种不同的光周期环境。对体重和睾丸发育进行了10周的检测。10周结束时，除24L组外，所有组动物的体重与成年动物相似。处于24L光周期环境中的动物体重增加较少。暴露于0L、2L和24L光周期环境会抑制睾丸发育，其睾丸重量与其他组存在显著差异。这些结果表明，成年沙鼠体重的维持似乎与光周期信号无关。暴露于极长（24L）和短光周期（<10小时）会导致成年沙鼠睾丸退化。此外，生命早期经历的不同光周期会影响青春期前睾丸的生长和体重增加。
