皮质醇及其衍生物(倍他米松)对青鳉性腺分化影响的探究  

Effects of betamethasone and cortisol on gonad differentiation of Japanese medaka Oryzias latipes

作　　者：向家志 苏冒亮 张俊彬[1,2] XIANG Jiazhi;SU Maoliang;ZHANG Junbin(National Demonstration Center for Experimental Fisheries Science Education,Shanghai Ocean University,Shanghai 201306,China;Shenzhen Key Laboratory of Marine Bioresource&Eco-Environmental Science,College of Life Sciences and Oceanography,Shenzhen University,Shenzhen 518060,China;Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province,College of Optoelectronic Engineering,Shenzhen University,Shenzhen 518060,China)

机构地区：[1]上海海洋大学水产科学国家级实验教学示范中心,上海201306 [2]深圳大学生命科学与海洋学院海洋生物资源与生态环境科学深圳重点实验室,深圳518060 [3]深圳大学光电工程学院光电子器件与系统教育部和广东省重点实验室,深圳518060

出　　处：《生态科学》2021年第5期16-22,共7页Ecological Science

基　　金：国家自然科学基金项目(41806177,41976108);中国博士后基金(2019M653010)。

摘　　要：皮质醇(Cortisol)是鱼类主要的糖皮质激素,其含量的高低变化会对鱼类性别分化与性激素合成产生关键影响。倍他米松(Betamethasone)是由人工合成的皮质醇衍生物,在多个国家和地区的自然水域中被频繁检测到,对鱼类的生殖造成了很大的危害。本研究以日本青鳉(Oryzias latipes)为实验对象,将获得的青鳉胚胎分别暴露于含20、200和2000 ng·L-1倍他米松或皮质醇的孵化液中,研究皮质醇及其衍生物-倍他米松对青鳉仔鱼阶段性激素合成酶与性腺分化的关键节点基因表达的影响,评估其对性腺分化与生殖内分泌的影响。结果表明,2000 ng·L-1皮质醇暴露加速青鳉胚胎孵化,孵化时间提前1天,200与2000 ng·L-1暴露组倍他米松胚胎孵化时长延缓2天。在仔鱼性腺分化阶段,皮质醇与倍他米松处理都引起类固醇激素合成酶与性腺分化的关键节点基因表达的显著变化。皮质醇处理下仔鱼的cyp19a1a、hsd17b3、hsd11b2基因表达水平均出现显著下降(p<0.05),对雌雄激素合成具有抑制效果,且抑制效果与暴露浓度呈正相关。倍他米松处理下,cyp19a1a、foxl2基因表达水平显著下降,且dmrt1基因表达水平显著上升(p<0.05),该结果提示倍他米松处理对青鳉仔鱼有潜在的雄性化。倍他米松与皮质醇暴露下,gsdf基因表达水平均下降,该结果表明两种糖皮质激素暴露会延缓仔鱼性腺的分化过程。综上所述,皮质醇与倍他米松的暴露均会干扰生殖内分泌系统,并延缓仔鱼的性腺分化,其中倍他米松暴露可能会诱导仔鱼的雄性化。Cortisol,the main glucocorticoid in fish,plays a key role in gonad differentiation and sex hormone synthesis of fish.Betamethasone,as a cortisol derivative,is widely detected in aquatic environment and can cause the harm to reproduction capacity of fish.In order to study the effect of cortisol and its derivative-betamethasone on the expression of key gene of sex hormone synthase and gonad differentiation in medaka(Oryzias latipes)larvae,and evaluate its effect on gonad differentiation and reproductive endocrine,the medaka embryos were exposed hatching-solution to larvae stage containing 20,200,2000 ng·L-1 betamethasone and cortisol,respectively.The results showed that 2000 ng·L-1 cortisol accelerated the embryos hatching time for 1 day,and 200 or 2000 ng·L-1 betamethasone delayed the embryos hatching time for 2 days.During the gonad differentiation stage of larvae,both cortisol and betamethasone treatment caused significant changes in the expression levels of steroid hormone synthase genes and gonad differentiation-related genes.The expression levels of cyp19a1a,hsd17b3,hsd11b2 genes all decreased significantly(p<0.05)by cortisol exposure,reflecting that cortisol treatment may inhibited sex hormone synthesis,and the inhibitory effect was positively correlated with cortisol concentration levels.Betamethasone exposure significantly reduced the expression levels of cyp19a1a,foxl2,and significantly increased the expression levels of dmrt1(p<0.05).the results showed that betamethasone exposure could cause virilization.The expression levels of gsdf gene decreased after cortisol or betamethasone treatment,which indicated the delay of the gonad differentiation of larvae.In summary,both cortisol and betamethasone exposure can disturb the reproductive endocrine system and delay the gonad differentiation of larvae.Betamethasone exposure can induce virilization of medaka larvae.

关 键 词：倍他米松 皮质醇 青鳉 性腺分化 基因表达 

分 类 号：X171.5[环境科学与工程—环境科学]