Transcriptome Comparison between Fetal and Adult Mouse Livers: Implications for Circadian Clock Mechanisms

Chengwei Li,Jianguo Wu,Xiaoling Zhong,Xiaodong Li,Shuang Yu,Shin Yamazaki

doi:10.1371/journal.pone.0031292

Abstract

Microarray transcriptome analyses of fetal mouse liver did not detect circadian expression rhythms of clock genes or clock-controlled genes, although some rhythmic transcripts that were likely not driven by endogenous cellular clocks were identified. This finding reveals a key distinction between the circadian oscillators in fetal and adult mouse livers. Thus, in this study, the transcriptomes of fetal and adult livers were systematically compared to identify differences in the gene expression profiles between these two developmental stages. Approximately 1000 transcripts were differentially enriched between the fetal and adult livers. These transcripts represent genes with cellular functions characteristic of distinct developmental stages. Clock genes were also differentially expressed between the fetal and adult livers. Developmental differences in liver gene expression might have contributed to the differences in oscillation status and functional states of the cellular circadian clock between fetal and adult livers.

Highlights

Circadian oscillations are generated by transcription-translation feedback loops formed by clock genes [1,2]
We did not detect circadian rhythms in transcript abundance for many of the clock genes and clock-controlled genes that are rhythmically expressed in adult liver
A set of robustly rhythmic transcripts were present in the fetal liver, which may have been regulated by maternal cues. These results indicate that the regulation of gene expression rhythms probably differ between the fetal and adult liver

Summary

Introduction

Circadian oscillations are generated by transcription-translation feedback loops formed by clock genes [1,2]. Studies on fetal liver during late gestation in mice or rats could not detect rhythmic expression of several clock genes at the tissue level [8,9]. We did not detect circadian rhythms in transcript abundance for many of the clock genes and clock-controlled genes that are rhythmically expressed in adult liver (results presented in the accompanying paper).

Results

Conclusion