C57小鼠肝、肾、脾、胸腺组织时钟基因的表达特点

Expression of clock gene in C57 mouse peripheral tissues

目的探测不同脏器组织中时钟基因的表达水平及其波动性。方法用实时荧光定量PCR方法检测C57小鼠肝、肾、脾和胸腺中4种重要时钟基因mBMAL1、mPER1、mCRY1和mCRY2的表达。结果肝和肾中4种时钟基因的表达水平均有显著波动(P<0.01);而脾中仅mBMAL1、mPER1、mCRY1的节律性表达明显(P<0.01,P<0.001,P<0.05),并且波动振幅较为平和;胸腺中4种时钟基因的表达均不具备昼夜波动的特征,同时表达水平也与其他3种组织存在显著差异(P<0.01)。时钟基因所构成的环路在不同组织中也不尽相同,mPER1的负反馈效应在肝中较为主要,mCRY1和mCRY2的负反馈效应在肾和脾中较为主要。结论不同周围组织的分子时钟存在着显著的差异,其相关正负反馈元件和环路有待进一步研究阐明。

Objective To detect temporal expression profiles of 4 principle clock genes （mBMAL1 ,mPER1 ,mCRY1 and mCRY2 ） in liver, kidney, spleen and testis. Methods Real time PCR assays were employed in this study. Results Cyclic expression of clock genes in liver and kidney was robust and significant （P 〈0. 01 ）. On the other hand, daily fluctuations of mBMAL1, roPER1, mCRY1 were only mild in spleen （P〈0. 01, P 〈0. 01, P 〈0. 05）, where mCRY2 did not show any significant daily variation. In testis, all of these clock genes did not vary with time, and their abundances were significantly different from other tissues. Conclusion Molecular feedback loops seem to function differently in different tissues, with roPER1 working more efficiently in liver and mCRY1/2 in kidney and spleen, which warrants further study to elucidate tissue dependant clock machinery.