title: Expression changes of mRNAs encoding kisspeptins and their receptors and gonadotropin-releasing hormones during early development and gonadal sex differentiation periods in the brain of chub mackerel (Scomber japonicus).
abstract: In recent years, brain kisspeptin system has been shown to be involved in diverse reproductive function, including sexual differentiation in vertebrates. Our previous reports demonstrated that the chub mackerel (Scomber japonicus) brain expresses two kisspeptin (kiss1, kiss2), two kisspeptin receptor (kissr1, kissr2) and three gonadotropin-releasing hormone (gnrh1, gnrh2, gnrh3) genes. In the present study, using quantitative real-time PCR (qRT-PCR) assays, we analysed expression changes of these genes during early development (0-30dphs) and gonadal sex differentiation periods (37-60dphs). Absolute expression level of kiss-kissr-gnrh in the whole head was higher between 0 and 15dphs, in comparison to later developmental periods. Histological analyses revealed presence of sexually differentiated males and females with testicular and ovarian features at 37, 45, and 60dphs. In both males and females, kiss2, kissr1, and kissr2 levels were higher at 37dph, in comparison to 45 and 60dphs, with kiss1 showing no significant differences. Levels of all three gnrh mRNAs were higher at 45dph, in comparison to 60dph. Changes in the expression level of kiss-kissr-gnrh mRNAs in different brain regions of sexually differentiated males and females indicated differences in their regional distribution. These results suggest possible involvement of Kiss-KissR-GnRH systems during early development and gonadal sex differentiation in the chub mackerel.
authors.affiliation: Laboratory of Marine Biology, Department of Bioresource Sciences, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan.
authors.forename: Sethu
authors.initials: S
authors.lastname: Selvaraj
authors.affiliation: Fisheries Research Institute of Karatsu, Department of Joint Research, Faculty of Agriculture, Kyushu University, Saga 847-0132, Japan.
authors.forename: Hajime
authors.initials: H
authors.lastname: Kitano
authors.affiliation: Laboratory of Marine Biology, Department of Bioresource Sciences, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Ohga
authors.affiliation: Laboratory of Marine Biology, Department of Bioresource Sciences, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Yamaguchi
authors.affiliation: Laboratory of Marine Biology, Department of Bioresource Sciences, Faculty of Agriculture, Kyushu University, Fukuoka 812-8581, Japan. Electronic address: rinya_m@agr.kyushu-u.ac.jp.
authors.forename: Michiya
authors.initials: M
authors.lastname: Matsuyama
mesh_terms: D000818:Animals; D003530:Cyprinidae / Q000378:metabolism*; D005260:Female; D005399:Fishes / Q000378:metabolism*; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism*; D006066:Gonads / Q000378:metabolism; D059648:Kisspeptins / Q000235:genetics / Q000378:metabolism*; D008297:Male; D010473:Perciformes / Q000378:metabolism*; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics*; D012733:Sex Differentiation / Q000502:physiology*
chemical_list: C106628:KISS1 protein, human; D059648:Kisspeptins; D012333:RNA, Messenger; C448022:gonadotropin-releasing hormone-III; D007987:Gonadotropin-Releasing Hormone; D011761:Pyrrolidonecarboxylic Acid
keywords: Chub mackerel; GnRHs; Gonadal sex differentiation; Kisspeptin receptors; Kisspeptins