title: Influence of photoperiodic history on clock genes and the circadian pacemaker in the rat retina.
abstract: The influence of seasonal lighting conditions on expression of clock genes and the circadian pacemaker was investigated in the rat retina. For this purpose, the 24-h profiles of nine clock genes (bmal1, clock, per1, per2, per3, dec1, dec2, cry1 and cry 2) and the arylalkylamine N-acetyltransferase gene as an indicator of the circadian pacemaker output were compared between light-dark periods of 8 : 16 and 16 : 8 h. The photoperiod influenced the daily patterns of the amount of transcript for per1, per3, dec2 and arylalkylamine N-acetyltransferase. This indicates that photoperiodic information modulates clock gene expression in addition to the circadian pacemaker of the retina. Under constant darkness, photoperiod-dependent changes in the daily profile of the level of transcript persisted for the arylalkylamine N-acetyltransferase gene but not for any of the clock genes. Hence, quantitative expression of each clock gene is influenced by the photoperiod only under the acute light-dark cycle, whereas the pacemaker is capable of storing photoperiodic information from past cycles.
authors.affiliation: Department of Anatomy and Cell Biology, Johannes Gutenbergy University, 55099 Mainz, Germany.
authors.forename: Nils
authors.initials: N
authors.lastname: Rohleder
authors.forename: Christina
authors.initials: C
authors.lastname: Langer
authors.forename: Christian
authors.initials: C
authors.lastname: Maus
authors.forename: Isabella
authors.initials: I
authors.lastname: Spiwoks-Becker
authors.forename: Angela
authors.initials: A
authors.lastname: Emser
authors.forename: Lydia
authors.initials: L
authors.lastname: Engel
authors.forename: Rainer
authors.initials: R
authors.lastname: Spessert
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002940:Circadian Rhythm / Q000235:genetics*; D005136:Eye Proteins / Q000235:genetics / Q000378:metabolism; D005260:Female; D015870:Gene Expression / Q000502:physiology / Q000528:radiation effects*; D005786:Gene Expression Regulation / Q000502:physiology / Q000528:radiation effects*; D008297:Male; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D017440:Photoperiod; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D012160:Retina / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013997:Time Factors
chemical_list: D005136:Eye Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger