目的 探讨12 h光照、12h黑暗交替(12 h-light and 12 h-dark cycle,12L/12D)光制条件下,小鼠外周血白细胞中4种节律基因bmal1、clock、cry1、per1近日节律性的表达特点. 方法 将48只雄性C57/BL6小鼠在12L/12D光制条件下饲养4周后,按随机数字表法分为6组,每组8只.分别在6个时相点(9:00、13:00、17:00、21:00、1:00、5:00)取外周血并分离白细胞.抽提总RNA,利用实时聚合酶链反应(polymerase chain reaction,PCR)方法检测小鼠外周血白细胞中bmal1、clock、cry1、per1 4种节律基因的mRNA水平.用余弦函数作曲线拟合,获取节律参数.并经one-ANOVA分析比较基因表达峰值和谷值的差异. 结果 在明暗交替光制条件下,bmal1、clock、cry1、per1 4种基因存在明显的近日节律性,各基因表达的峰值明显高于谷值(P＜0.01).利用拟合方程预测的clock表达峰值相位时间在5:00左右,雨bmal1、cry1、per1基因表达的峰值时间在13:00-15:00左右.clock表达的峰值时间比bmal1超前,峰值及振幅也比bmal1高(P＜0.01);而cry1和per1表达的峰值时间、峰值大小比较接近. 结论 C57/BL6小鼠外周血白细胞bmal1、clock、cry1、per1基因表达存在明显的近日节律性.clock在正反馈中的作用强于bmal1,而cry1、per1在负反馈中的作用相似.“,”Objective To investigate circadian rhythm of four genes (bmal1,clock,cry1,per1) in mouse peripheral white blood cells under the 12 h-light and 12 h-dark cycle (12L/12D) condition.Methods Forty-eight male mice were kept under the light regime of 12L/12D for four weeks.According to random number table,they were randomly and averagely divided into 6 groups.Then,the blood samples were taken and white blood cells were separated every four hours in a circadian day (9:00,13:00,17:00,21:00,1:00 and 5:00).The total RNA was extracted from the white blood cells and the mRNA level of each gene was quantified by real-time polymerase chain reaction (real-time PCR).The data were fitted by cosine function for getting the rhythm.The difference between apex and trough was analyzed by one-ANOVA.Results Under the light regime of 12L/12D,the four genes in peripheral white blood cells showed a significant circadian oscillation with different apex and trough.The apexes of four genes were higher than the troughs (P＜0.01).The equation fitted apex phase of clock gene was at about 5:00,compared to the apex time of the other three genes were at about 13:00-15:00.The apex time of clock mRNA was ahead of brnal1,and the apex and amplitude of it were higher than those of brnal1.However,the mRNAs of cry1 and per1 showed a similar apex time and apex level.Conclusions The findings demonstrate that the expression of the four genes in white blood cells shows an obvious circadian rhythm.It seems that clock plays more important role than bmal1 in the positive regulation,and cry1 and per1 play a similar role in negative regulation.This result will not only be helpful to understand the circadian fluctuation of immune function,but also to provide a target for implementing diagnosis and therapy of immune disorders.Further study is needed to elucidate the control effect of these genes in different immune cells in peripheral blood.