HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 292/3/R1224    most recent 00184.2006v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (11) Citing Articles via Google Scholar Google Scholar Articles by Sládek, M. Articles by Sumová, A. Search for Related Content PubMed PubMed Citation Articles by Sládek, M. Articles by Sumová, A.

DEVELOPMENTAL PHYSIOLOGY AND PREGNANCY

Postnatal ontogenesis of the circadian clock within the rat liver

Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic

Submitted 15 March 2006 ; accepted in final form 29 October 2006

In mammals, the circadian oscillator within the suprachiasmatic nuclei (SCN) entrains circadian clocks in numerous peripheral tissues. Central and peripheral clocks share a molecular core clock mechanism governing daily time measurement. In the rat SCN, the molecular clockwork develops gradually during postnatal ontogenesis. The aim of the present work was to elucidate when during ontogenesis the expression of clock genes in the rat liver starts to be rhythmic. Daily profiles of mRNA expression of clock genes Per1, Per2, Cry1, Clock, Rev-Erb, and Bmal1 were analyzed in the liver of fetuses at embryonic day 20 (E20) or pups at postnatal age 2 (P2), P10, P20, P30, and in adults by real-time RT-PCR. At E20, only a high-amplitude rhythm in Rev-Erb and a low-amplitude variation in Cry1 but no clear circadian rhythms in expression of other clock genes were detectable. At P2, a high-amplitude rhythm in Rev-Erb and a low-amplitude variation in Bmal1 but no rhythms in expression of other genes were detected. At P10, significant rhythms only in Per1 and Rev-Erb expression were present. At P20, clear circadian rhythms in the expression of Per1, Per2, Rev-Erb, and Bmal1, but not yet of Cry1 and Clock, were detected. At P30, all clock genes were expressed rhythmically. The phase of the rhythms shifted between all studied developmental periods until the adult stage was achieved. The data indicate that the development of the molecular clockwork in the rat liver proceeds gradually and is roughly completed by 30 days after birth.

circadian rhythms; clock genes; development; peripheral clock; rat

This article has been cited by other articles:

				S. Yamazaki, T. Yoshikawa, E. W. Biscoe, R. Numano, L. M. Gallaspy, S. Soulsby, E. Papadimas, P. Pezuk, S. E. Doyle, H. Tei, et al. Ontogeny of Circadian Organization in the Rat J Biol Rhythms, February 1, 2009; 24(1): 55 - 63. [Abstract] [PDF]