Transcriptional analysis of breast circadian clock

Circadian clocks drive ~24 hr rhythms in tissue physiology. They rely on transcriptional/translational feedback loops driven by interacting networks of clock complexes.To gain insights into the role of the mammary clock, circadian time-series microarrays were performed to identify rhythmic genes in vivo. Breast tissues were isolated at 4 hr intervals for two circadian (24 hourly) cycles, from mice kept under constant darkness to avoid any light- or dark-driven genes.昼夜节律钟（Circadian clock）可驱动组织生理学中约24小时的节律性变化。此类生物钟依赖于由钟复合物相互作用网络介导的转录-翻译反馈环路。为深入解析乳腺生物钟的生物学作用，研究人员开展了昼夜节律时序微阵列（circadian time-series microarray）实验，以在体内（in vivo）鉴定节律性表达基因。实验选取饲养于持续黑暗环境中的小鼠以规避光/暗诱导的基因表达，随后每4小时采集一次乳腺组织，连续采集两个昼夜节律周期（即两个24小时周期）。