Effects of light on the expression patterns of circadian clock-related genes in the peripheral lymphocytes

Objective To explore the effects of light on the expression patterns of clock and clock-related genes in peripheral lymphocytes.To develop basic knowledge needed for clinical application of the circadian clock.Methods One hundred Sprague-Dawley rats were housed under constant dark(DD)or normal light-dark(LD 12:12)conditions for six weeks.Peripheral iymphoeytes were collected at different time points.The expression level of the clock gene and melatonin receptor genes mt1 and mt2 were detected using semi-quantitative RT-PCR.The data were analyzed with cosine software.Results Circadian expression of the genes was observed in both groups,but the peak phase,amplitude and strength of expression of each gene differed with the light conditions.Conclusion Light influences the expression of clock and clock-related genes in rats' peripheral lymphocytes.The clock gene might play an important role in regulating the expression of mt1 and mt2. Key words: Circadian clock; Peripheral lymphocytes; Clock gene; Melatonin receptors