title: Genetic Evidence for Multifactorial Control of the Reproductive Axis in Zebrafish.
abstract: It is generally believed that kisspeptin and gonadotropin-releasing hormone (GnRH) are required for reproduction in vertebrates. In this study, we generated gnrh3-null zebrafish and found that gnrh3 mutation did not impair gonad development and reproductive capacity. Moreover, zebrafish triple knockout mutant lacking gnrh3 and the 2 kiss1s genes undergo normal puberty and gonad maturation. The expression of follicle-stimulating hormone beta (fshβ) and luteinizing hormone beta (lhβ) was not significantly altered whereas the expression of neuropeptide Y (npy), tachykinin 3 (tac3), and secretogranin-II (sgII) was significantly increased in the triple knockout mutant, suggesting that compensation mechanisms exist to stimulate the reproductive axis in the absence of kiss and gnrh. Our results challenge the prevailing view that GnRH is indispensable for reproduction across species. These data provide genetic evidence that different mechanisms have evolved for the neuroendocrine control of reproduction between mammals and fish: pulsatile release of GnRH to the portal system is the final gateway to stimulate the reproductive axis in mammals, whereas multiple factors act in parallel with GnRH to stimulate the reproductive axis in certain fish species.
authors.affiliation: State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals, and the Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China.|School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals, and the Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Haipei
authors.initials: H
authors.lastname: Tang
authors.affiliation: State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals, and the Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China.|School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Xie
authors.affiliation: State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals, and the Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Shuisheng
authors.initials: S
authors.lastname: Li
authors.affiliation: State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals, and the Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Xiaochun
authors.initials: X
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals, and the Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Haoran
authors.initials: H
authors.lastname: Lin
authors.affiliation: State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals, and the Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China.|School of Biomedical Sciences Core Laboratory, The Chinese University of Hong Kong Shenzhen Research Institute, Shenzhen, China.
authors.forename: Christopher H K
authors.initials: CH
authors.lastname: Cheng
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000235:genetics*; D059648:Kisspeptins / Q000235:genetics*; D008297:Male; D009479:Neuropeptides / Q000378:metabolism; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives*; D012098:Reproduction / Q000235:genetics*; D012741:Sexual Maturation; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000235:genetics*
chemical_list: C527845:Kiss1 protein, zebrafish; D059648:Kisspeptins; D009479:Neuropeptides; D029961:Zebrafish Proteins; C448022:gonadotropin-releasing hormone-III; D007987:Gonadotropin-Releasing Hormone; D011761:Pyrrolidonecarboxylic Acid