文章基本信息

标题：Circadian gene expression in mammalian fibroblasts revealed by real-time luminescence reporting: Temperature compensation and damping
本地全文：下载
作者：Mariko Izumo ; Carl Hirschie Johnson ; Shin Yamazaki 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2003
卷号：100
期号：26
页码：16089-16094
DOI：10.1073/pnas.2536313100
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Mammalian cells such as rat-1 fibroblasts have been shown to exhibit daily oscillations in the expression of several gene transcripts in culture. After induction, these oscillations persist with a period of {approx}24 h for several days. This characteristic suggests that the oscillations are controlled by a circadian clock, but the crucial criterion of temperature compensation has not been demonstrated for rat-1 fibroblasts. We have developed an automated assay of circadian expression of the mPer1 promoter in rat-1 fibroblasts that have been stably transfected with a luciferase reporter. Using this cell culture-based in vitro luminescent reporter assay, we found that the daily oscillation of mPer1 promoter activity in rat-1 cells is temperature compensated over the range of 28.5-36.5{degrees}C. This finding means that these oscillations are bona fide circadian rhythms. Moreover, the circadian clock of these homeothermic mammalian cells not only is temperature compensated but also is overcompensated such that it runs faster at cooler temperatures (Q10 of 0.85-0.88). The oscillations in rat-1 fibroblasts damp more rapidly at cooler temperatures, and damping is not due to cells becoming unhealthy because a second stimulus will reinitiate a robust rhythm. These data show that rat-1 cell cultures that are stably transfected with luminescence reporters are an excellent model system for studying circadian clocks at the cellular level in mammals.
关键词：rat-1 ; luciferase ; biological clock ; Per1