title: Diurnal expression patterns of neurohypophysial hormone genes in the brain of the threespot wrasse Halichoeres trimaculatus.
abstract: The aim of this study was to determine the involvement of neurohypophysial hormones in the diurnal patterns of the threespot wrasse Halichoeres trimaculatus, which is common in coral reefs and exhibits daily behavioral periodicity. Prohormone cDNAs of the neurohypophysial peptides, arginine vasotocin (AVT) and isotocin (IT), were cloned by 3'- and 5'-rapid amplification of cDNA ends (RACE). The distribution and expression patterns of pro-AVT and -IT mRNAs in the brain were determined using reverse-transcription polymerase chain reaction (RT-PCR) and real-time quantitative PCR, respectively. The respective full-length cDNAs of pro-AVT and -IT were 945 and 755 bp in length, respectively. The deduced amino acid sequences for pro-AVT and pro-IT were 154 and 156 residues in length, respectively. Both pro-peptides contained a signal sequence followed by the respective hormones and neurophysin connected by a Gly-Lys-Arg bridge. Pro-AVT mRNA was detected only in the hypothalamus area, while pro-IT mRNA in the whole part of the brain. The relative abundance of pro-AVT and -IT mRNA varied according to time of day; it was significantly greater at 12:00 h than at 24:00 h. Following intraperitoneal administration of melatonin, pro-AVT mRNA abundance in the brain decreased, while pro-IT mRNA abundance remained unchanged. These results demonstrate that daily fluctuations of pro-AVT and pro-IT levels in the brain of threespot wrasse are differentially regulated.
authors.affiliation: Department of Biology, Chemistry and Marine Sciences, Faculty of Science, University of Ryukyu, Nishihara, Okinawa 903-0213, Japan.
authors.forename: Sung-Pyo
authors.initials: SP
authors.lastname: Hur
authors.forename: Yuki
authors.initials: Y
authors.lastname: Takeuchi
authors.forename: Yuriko
authors.initials: Y
authors.lastname: Esaka
authors.forename: Wambiji
authors.initials: W
authors.lastname: Nina
authors.forename: Yong-Ju
authors.initials: YJ
authors.lastname: Park
authors.forename: Hyeong-Cheol
authors.initials: HC
authors.lastname: Kang
authors.forename: Hyung-Bok
authors.initials: HB
authors.lastname: Jeong
authors.forename: Young-Don
authors.initials: YD
authors.lastname: Lee
authors.forename: Se-Jae
authors.initials: SJ
authors.lastname: Kim
authors.forename: Akihiro
authors.initials: A
authors.lastname: Takemura
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000378:metabolism*; D002940:Circadian Rhythm / Q000235:genetics; D015870:Gene Expression; D008969:Molecular Sequence Data; D010121:Oxytocin / Q000031:analogs & derivatives* / Q000235:genetics / Q000378:metabolism; D010473:Perciformes / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D014668:Vasotocin / Q000235:genetics / Q000378:metabolism*
chemical_list: D012333:RNA, Messenger; D010121:Oxytocin; C008215:isotocin; D014668:Vasotocin