title: Gender associated circadian oscillations of the clock genes in rat choroid plexus.
abstract: It is well-documented that circadian rhythms are controlled by the circadian master clock of the mammalian brain, located in the suprachiasmatic nucleus (SCN) of the hypothalamus. The SCN clockwork is a cell autonomous mechanism consisting of a series of interlocked transcriptional/post-translational feedback loops. In turn, the SCN controls the seasonal rhythmicity of various biological processes, in particular the secretion pattern of hormones. Although the effects of gonadal hormones on circadian rhythmicity are clearly established, how the SCN integrates and regulates these hormonal stimuli remains unknown. We have previously found that clock genes are expressed in the choroid plexus (CP). Therefore, we compared the circadian expression of these genes in female and male rat CP. We show that there is a 24-h rhythm in the expression of Per2 and Cry2 in males and females. Bmal1 and Per1 expression also varied along the day, but only in females. Bmal1, Clock and Per1 mRNA did not show any significant differences in the CP of males. Moreover, data from cultured CP cells collected at different timepoints revealed significant circadian rhythms in mRNA abundance of Bmal1, Clock and Per2. In conclusion, our data show that the rat CP expresses all canonical clock genes and that their circadian expression differs between genders suggesting that hormones can regulate circadian rhythmicity in CP.
authors.affiliation: CICS-UBI-Health Sciences Research Centre, University of Beira Interior, Covilhã, Portugal, tquintela@fcsaude.ubi.pt.
authors.forename: T
authors.initials: T
authors.lastname: Quintela
authors.forename: C
authors.initials: C
authors.lastname: Sousa
authors.forename: F M
authors.initials: FM
authors.lastname: Patriarca
authors.forename: I
authors.initials: I
authors.lastname: Gonçalves
authors.forename: C R A
authors.initials: CR
authors.lastname: Santos
mesh_terms: D056930:ARNTL Transcription Factors / Q000235:genetics*; D000818:Animals; D056926:CLOCK Proteins / Q000235:genetics; D002831:Choroid Plexus / Q000378:metabolism*; D002940:Circadian Rhythm / Q000235:genetics*; D056931:Cryptochromes / Q000235:genetics*; D005260:Female; D008297:Male; D056950:Period Circadian Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012737:Sex Factors; D013997:Time Factors
chemical_list: D056930:ARNTL Transcription Factors; C000598703:Arntl protein, rat; C538968:Cry2 protein, rat; D056931:Cryptochromes; C539024:Per1 protein, rat; C513311:Per2 protein, rat; D056950:Period Circadian Proteins; D012333:RNA, Messenger; D056926:CLOCK Proteins; C538945:Clock protein, rat