Expression analysis of circadian genes in oocytes and preimplantation embryos of cattle and rabbits.
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.
Amano
Tomoko
T
Department of Genetic Engineering, Kinki University, Kinokawa, Wakayama, Japan. amino@waka.kindai.ac.jp
Tokunaga
Kaori
K
Kakegawa
Reiko
R
Yanagisawa
Ayaka
A
Takemoto
Atsushi
A
Tatemizo
Atsuhiro
A
Watanabe
Tatsuya
T
Hatanaka
Yuki
Y
Matsushita
Akinori
A
Kishi
Masao
M
Anzai
Masayuki
M
Kato
Hiromi
H
Mitani
Tasuku
T
Kishigami
Satoshi
S
Saeki
Kazuhiro
K
Hosoi
Yoshihiko
Y
Iritani
Akira
A
Matsumoto
Kazuya
K
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
D056930:ARNTL Transcription Factors; D056931:Cryptochromes; D056950:Period Circadian Proteins; D012333:RNA, Messenger; D056926:CLOCK Proteins