Laboratory of Animal Physiology, Graduate School of Bioagricultural Sciences, Nagoya University, Chikusa, Nagoya, Japan.
Anim Sci J. 2009 Jun;80(3):328-32. doi: 10.1111/j.1740-0929.2009.00628.x.
Photoperiodism is an adaptation mechanism that enables animals to predict seasonal changes in the environment. Japanese quail is the best model organism for studying photoperiodism. Although the recent availability of chicken genome sequences has permitted the expansion from single gene to genome-wide transcriptional analysis in this organism, the photoperiodic response of the domestic chicken is less robust than that of the quail. Therefore, in the present study, we examined the photoperiodic response of the red jungle fowl (Gallus gallus), a predecessor of the domestic chicken, to test whether this animal could be developed as an ideal model for studying the molecular mechanisms of seasonal reproduction. When red jungle fowls were transferred from short-day- to long-day conditions, gonadal development and an increase in plasma LH concentration were observed. Furthermore, rapid induction of thyrotropin beta subunit, a master regulator of photoperiodism, was observed at 16 h after dawn on the first long day. In addition, the long-day condition induced the expression of type 2 deiodinase, the key output gene of photoperiodism. These results were consistent with the results obtained in quail and suggest that the red jungle fowl could be an ideal model animal for the genome-wide transcriptional analysis of photoperiodism.
光周期现象是一种适应机制，使动物能够预测环境中的季节性变化。日本鹌鹑是研究光周期现象的最佳模式生物。尽管最近鸡的基因组序列已经可用，允许在这个生物中从单个基因扩展到全基因组转录分析，但家鸡的光周期反应不如鹌鹑那样强烈。因此，在本研究中，我们检查了红原鸡（Gallus gallus），即家鸡的前身，对光周期的反应，以测试这种动物是否可以发展成为研究季节性繁殖分子机制的理想模型。当红原鸡从短日条件转移到长日条件时，观察到性腺发育和血浆 LH 浓度增加。此外，在第一个长日的黎明后 16 小时，快速诱导了促甲状腺素β亚基的表达，这是光周期的主要调节因子。此外，长日条件诱导了 2 型脱碘酶的表达，这是光周期的关键输出基因。这些结果与鹌鹑的结果一致，表明红原鸡可能是光周期全基因组转录分析的理想模型动物。
