title: Expression analysis of circadian genes in oocytes and preimplantation embryos of cattle and rabbits.
abstract: We previously showed that circadian genes clock, bmal1, cry1, cry2, per1, and per2 are expressed and function as maternal mRNA regulating events in the oocytes and preimplantation embryos of mice. Recent evidence indicates however that either or both expression profiles of circadian genes in some tissues, and transcript sequences of circadian genes, differ to generate the physiological differences between diurnal and nocturnal species. We therefore investigated the expression profiles of circadian genes in oocytes and preimplantation embryos of species other than mice, namely cattle and rabbits, representing diurnal and nocturnal species, respectively, and determined the protein sequences of circadian genes in these species. Quantitative real-time PCR revealed that all circadian genes considered in this study were present in the oocytes and preimplantation embryos of both species, and the transcript amounts of clock, cry1 and per1 contained in oocytes were significantly higher than in preimplantation embryos of both species. The transcripts of clock, cry1, and per1 of cattle and rabbits were determined by primer walking, and functional domains in the estimated amino acid sequences were compared between cattle and rabbits and with those of humans and mice. The sequences of clock, cry1, and per1 in cattle and rabbits closely resembled those in mice (85-100% homologies), and no difference based on diurnality or nocturnality was observed. These findings suggest that circadian genes in the oocytes and preimplantation embryos of mammals fulfill the same functions across species as maternal mRNA.
authors.affiliation: Department of Genetic Engineering, Kinki University, Kinokawa, Wakayama, Japan. amino@waka.kindai.ac.jp
authors.forename: Tomoko
authors.initials: T
authors.lastname: Amano
authors.forename: Kaori
authors.initials: K
authors.lastname: Tokunaga
authors.forename: Reiko
authors.initials: R
authors.lastname: Kakegawa
authors.forename: Ayaka
authors.initials: A
authors.lastname: Yanagisawa
authors.forename: Atsushi
authors.initials: A
authors.lastname: Takemoto
authors.forename: Atsuhiro
authors.initials: A
authors.lastname: Tatemizo
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Watanabe
authors.forename: Yuki
authors.initials: Y
authors.lastname: Hatanaka
authors.forename: Akinori
authors.initials: A
authors.lastname: Matsushita
authors.forename: Masao
authors.initials: M
authors.lastname: Kishi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Anzai
authors.forename: Hiromi
authors.initials: H
authors.lastname: Kato
authors.forename: Tasuku
authors.initials: T
authors.lastname: Mitani
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kishigami
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Saeki
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Hosoi
authors.forename: Akira
authors.initials: A
authors.lastname: Iritani
authors.forename: Kazuya
authors.initials: K
authors.lastname: Matsumoto
mesh_terms: D056930:ARNTL Transcription Factors / Q000737:chemistry / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D001755:Blastocyst / Q000378:metabolism*; D056926:CLOCK Proteins / Q000737:chemistry / Q000235:genetics; D002417:Cattle / Q000196:embryology*; D002940:Circadian Rhythm / Q000235:genetics*; D056931:Cryptochromes / Q000737:chemistry / Q000235:genetics; D005260:Female; D020869:Gene Expression Profiling / Q000662:veterinary*; D006801:Humans; D008297:Male; D009865:Oocytes / Q000378:metabolism*; D056950:Period Circadian Proteins / Q000737:chemistry / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D011817:Rabbits / Q000196:embryology*; D016415:Sequence Alignment
chemical_list: D056930:ARNTL Transcription Factors; D056931:Cryptochromes; D056950:Period Circadian Proteins; D012333:RNA, Messenger; D056926:CLOCK Proteins