title: Sex biased expression of ghrelin and GHSR associated with sexual size dimorphism in yellow catfish.
abstract: Sexual size dimorphism has been observed in many cultivable fish species including yellow catfish, in which male fish grow much faster than female fish. Ghrelin is a potent stimulator of pituitary growth hormone (GH) release and known to potentially promote food intake and body weight gain. In order to investigate the molecular mechanism of sexual size dimorphism in yellow catfish (Pelteobagrus fulvidraco), ghrelin and its functional receptor, growth hormone secretagogue receptor (GHSR) cDNAs were cloned. Real-time PCR indicated that both ghrelin and GHSR were more highly expressed in hypothalamus and gut of male fish than female. During normal larval development, expression of ghrelin and GHSR genes was significantly higher in males than in females. 17a-Methyltestosterone (MT) treatment enhanced the expression of ghrelin in female larval fish and GHSR in both sexes, whereas the expression of ghrelin in male larval fish increased in the beginning, then decreased as the treatment time prolonged. Furthermore, the expression of ghrelin and GHSR in male juvenile was significantly increased compared with female juvenile, in short and long term fasting periods, suggesting that male fish may have a better appetite than female during fasting. Our results demonstrate that sex difference in the expression of ghrelin and GHSR may be involved in sexual size dimorphism by regulating feeding and GH/IGF signaling in yellow catfish.
authors.affiliation: College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Zhang
authors.affiliation: College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Wenge
authors.initials: W
authors.lastname: Ma
authors.affiliation: College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Huazhong Agricultural University, Wuhan 430070, China. Electronic address: heyan@mail.hzau.edu.cn.
authors.forename: Yan
authors.initials: Y
authors.lastname: He
authors.affiliation: College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Junjie
authors.initials: J
authors.lastname: Wu
authors.affiliation: College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Farman Ullah
authors.initials: FU
authors.lastname: Dawar
authors.affiliation: College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Ren
authors.affiliation: College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Huazhong Agricultural University, Wuhan 430070, China.
authors.forename: Xiaohan
authors.initials: X
authors.lastname: Zhao
authors.affiliation: College of Fisheries, Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Huazhong Agricultural University, Wuhan 430070, China. Electronic address: jmei@mail.hzau.edu.cn.
authors.forename: Jie
authors.initials: J
authors.lastname: Mei
mesh_terms: D000818:Animals; D049628:Body Size / Q000235:genetics*; D002397:Catfishes / Q000235:genetics / Q000254:growth & development; D005260:Female; D018507:Gene Expression Regulation, Developmental; D054439:Ghrelin / Q000096:biosynthesis* / Q000235:genetics; D008297:Male; D008777:Methyltestosterone / Q000494:pharmacology; D054440:Receptors, Ghrelin / Q000096:biosynthesis* / Q000235:genetics; D012727:Sex Characteristics
chemical_list: D054439:Ghrelin; D054440:Receptors, Ghrelin; D008777:Methyltestosterone
keywords: Fasting; GHSR; Ghrelin; Pelteobagrus fulvidraco; Sexual dimorphism