title: Subchronic effects of cadmium on the gonads, expressions of steroid hormones and sex-related genes in tilapia Oreochromis niloticus.
abstract: Cadmium (Cd) is one of the most toxic heavy metals in aquatic ecosystem which affects fish health and aquaculture. In the present study, we examined the bioaccumulation of Cd in the gonads of tilapia via dissolved and dietary routes. We evaluated the subchronic effects of Cd on the histology of gonads, steroid hormone levels and sex-related gene expressions in tilapia. In addition, we also studied maternal transfer of Cd. Our results indicated that Cd was accumulated significantly in both ovary and testis from both exposure routes. Histopathological analysis showed that Cd induced ovary and testis injuries. Estradiol levels were significantly increased in dissolved Cd exposed female fish. In addition, the Cd exposure displayed different effects on gene expressions in gonads. In females, the estrogen receptor (ERα) was stimulated in dissolved Cd-exposed fish at 70.32 and 143.78 μg/L for 30 days and in fish at 143.78 μg/L for 60 days. Vitellogenin expression was significantly down-regulated in the ovary of dissolved Cd-exposed fish. In testis, GR expression was elevated after 60 days of dissolved Cd and dietary exposure. Furthermore, Cd level was significantly higher in the eggs than that in the fry. Our results demonstrated that both dissolved and dietary Cd exposures affected gonad development by altering steroid hormone levels and sex-related gene expressions in tilapia.
authors.affiliation: Wuxi Fisheries College, Nanjing Agricultural University, Wuxi, 214081, Jiangsu, China.|Guangxi Key Laboratory of Aquatic Genetic Breeding and Healthy Aquaculture, Guangxi Academy of Fishery Sciences, Nanning, 530021, Guangxi, China.|Faculty of Fisheries and Life Science, Shanghai Ocean University, Shanghai, 201306, China.
authors.forename: Yongju
authors.initials: Y
authors.lastname: Luo
authors.affiliation: Faculty of Fisheries and Life Science, Shanghai Ocean University, Shanghai, 201306, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Shan
authors.affiliation: Guangxi Key Laboratory of Aquatic Genetic Breeding and Healthy Aquaculture, Guangxi Academy of Fishery Sciences, Nanning, 530021, Guangxi, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Zhong
authors.affiliation: Guangxi Key Laboratory of Aquatic Genetic Breeding and Healthy Aquaculture, Guangxi Academy of Fishery Sciences, Nanning, 530021, Guangxi, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Faculty of Fisheries and Life Science, Shanghai Ocean University, Shanghai, 201306, China.
authors.forename: Wenzhi
authors.initials: W
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Ecological Animal Husbandry and Environmental Veterinary Medicine, College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, 030801, Shanxi, China.
authors.forename: Jinling
authors.initials: J
authors.lastname: Cao
authors.affiliation: Guangxi Key Laboratory of Aquatic Genetic Breeding and Healthy Aquaculture, Guangxi Academy of Fishery Sciences, Nanning, 530021, Guangxi, China.
authors.forename: Zhongbao
authors.initials: Z
authors.lastname: Guo
authors.affiliation: Guangxi Key Laboratory of Aquatic Genetic Breeding and Healthy Aquaculture, Guangxi Academy of Fishery Sciences, Nanning, 530021, Guangxi, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Xiao
authors.affiliation: Faculty of Fisheries and Life Science, Shanghai Ocean University, Shanghai, 201306, China.
authors.forename: Fulin
authors.initials: F
authors.lastname: He
authors.affiliation: Guangxi Autonomous Region Center for Analysis and Test Research, Nanning, 530022, Guangxi, China.
authors.forename: Yifan
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Guangxi Autonomous Region Center for Analysis and Test Research, Nanning, 530022, Guangxi, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Li
authors.affiliation: Guangxi Autonomous Region Center for Analysis and Test Research, Nanning, 530022, Guangxi, China.
authors.forename: Heming
authors.initials: H
authors.lastname: Huang
authors.affiliation: Wuxi Fisheries College, Nanjing Agricultural University, Wuxi, 214081, Jiangsu, China. xup@ffrc.cn.|Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Scientific Observing and Experimental Station of Fishery Resources and Environment in the Lower Reaches of the Yangtze River, Wuxi, 214081, Jiangsu, China. xup@ffrc.cn.
authors.forename: Pao
authors.initials: P
authors.lastname: Xu
mesh_terms: D000818:Animals; D002104:Cadmium / Q000633:toxicity*; D023681:Cichlids / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005260:Female; D015870:Gene Expression / Q000187:drug effects*; D012739:Gonadal Steroid Hormones / Q000097:blood*; D008297:Male; D010053:Ovary / Q000187:drug effects / Q000473:pathology*; D011897:Random Allocation; D013737:Testis / Q000187:drug effects / Q000473:pathology*; D059550:Toxicity Tests, Subchronic; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D012739:Gonadal Steroid Hormones; D014874:Water Pollutants, Chemical; D002104:Cadmium
keywords: Cadmium; Gonad; Maternal transfer; Nile tilapia; Reproduction