title: Mouse dexamethasone-induced RAS protein 1 gene is expressed in a circadian rhythmic manner in the suprachiasmatic nucleus.
abstract: We identified the Dexamethasone-induced RAS protein 1 (Dexras1) gene as a cycling gene in the suprachiasmatic nucleus (SCN). Investigation of the whole brain using in situ hybridization demonstrated the localization of the expression of the gene in the SCN, thalamus, piriform cortex and hippocampus. However, rhythmic expression of the gene was observed only in the SCN. The rhythmic change in gene expression during 1 day was approximately five-fold, and the maximum expression was observed during subjective night. Real-time PCR using the SCN, paraventricular nucleus and cortex confirmed these results. Next, we analyzed the expression of the Dexras1 gene in the SCN of cryptochrome (Cry) 1 and 2 double knockout mice. We found that the rhythmic expression disappeared. The results indicate that Dexras1 rhythmicity and levels are dependent upon CRYs. This is the first time that the G protein, which may be involved in the input pathway, has been isolated as a cycling gene in the SCN.
authors.affiliation: Transcriptome Profiling Group, National Institute of Radiological Sciences, Anagawa 4-9-1, Inage-ku, Chiba 263-8555, Japan.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Takahashi
authors.forename: Nanae
authors.initials: N
authors.lastname: Umeda
authors.forename: Yoko
authors.initials: Y
authors.lastname: Tsutsumi
authors.forename: Ryutaro
authors.initials: R
authors.lastname: Fukumura
authors.forename: Hajime
authors.initials: H
authors.lastname: Ohkaze
authors.forename: Mitsugu
authors.initials: M
authors.lastname: Sujino
authors.forename: Gijsbertus
authors.initials: G
authors.lastname: van der Horst
authors.forename: Akira
authors.initials: A
authors.lastname: Yasui
authors.forename: Shin-Ichi T
authors.initials: ST
authors.lastname: Inouye
authors.forename: Akira
authors.initials: A
authors.lastname: Fujimori
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Ohhata
authors.forename: Ryoko
authors.initials: R
authors.lastname: Araki
authors.forename: Masumi
authors.initials: M
authors.lastname: Abe
mesh_terms: D000818:Animals; D002940:Circadian Rhythm / Q000235:genetics*; D056931:Cryptochromes; D003907:Dexamethasone; D029721:Drosophila Proteins; D005136:Eye Proteins; D005420:Flavoproteins / Q000235:genetics; D019204:GTP-Binding Proteins; D005786:Gene Expression Regulation; D017403:In Situ Hybridization; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D020559:Monomeric GTP-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D017956:Photoreceptor Cells, Invertebrate; D016133:Polymerase Chain Reaction / Q000379:methods; D012333:RNA, Messenger / Q000032:analysis; D043562:Receptors, G-Protein-Coupled; D013493:Suprachiasmatic Nucleus / Q000502:physiology*; D018631:ras Proteins
chemical_list: D056931:Cryptochromes; D029721:Drosophila Proteins; D005136:Eye Proteins; D005420:Flavoproteins; D012333:RNA, Messenger; D043562:Receptors, G-Protein-Coupled; C119828:cry protein, Drosophila; D003907:Dexamethasone; D019204:GTP-Binding Proteins; C498511:Rasd1 protein, mouse; D020559:Monomeric GTP-Binding Proteins; D018631:ras Proteins