尼罗罗非鱼卵巢发育过程中性类固醇激素与卵黄蛋白原含量变化及Vtg mRNA表达特征  

Changes in sex steroid hormones, vitellogenin content, and Vtg mRNA expression during ovarian development in Oreochromis niloticus

作　　者：罗明坤[1] 赵金良[1] Thammaratsuntorn Jeerawat 李传阳[1] 魏继海 赵永华[1] 

机构地区：[1]上海海洋大学农业部淡水水产种质资源重点实验室,上海201306

出　　处：《中国水产科学》2015年第6期1123-1132,共10页Journal of Fishery Sciences of China

基　　金：国家现代农业产业技术体系专项资金(CARS-49-4B);水产动物遗传育种中心上海市协同创新中心项目(ZF1206)

摘　　要：通过组织切片、酶联免疫吸附及荧光定量PCR等方法,研究了尼罗罗非鱼(Oreochromis niloticus)卵巢发育过程中性类固醇激素(雌二醇E2、孕酮P)、卵黄蛋白原(Vtg)含量及Vtg mRNA相对表达水平变化规律。结果表明,尼罗罗非鱼性腺指数(GSI)与卵巢成熟发育间呈同步性变化,Ⅴ期达到峰值。血清中E2含量自卵巢Ⅱ期开始显著升高,Ⅳ期达到峰值,Ⅴ期后显著下降;血清P含量自卵巢Ⅱ期开始不断升高,Ⅴ期达到峰值,Ⅵ期显著下降;E2、P分别在卵巢成熟发育前期与后期发挥作用。肝中Vtg含量先升、后降,Ⅳ期达峰值;血清、卵巢中Vtg含量均自Ⅱ期开始增加,Ⅴ期达峰值,Ⅵ期显著降低;不同组织中Vtg含量变化与卵巢成熟发育间存在密切关联。肝中Vtg mRNA表达水平在Ⅲ期达到峰值,Ⅳ期后持续下调;卵巢中Vtg mRNA表达水平相对较低,Ⅴ期达到峰值;初步推测肝、卵巢同是尼罗罗非鱼Vtg合成部位,肝是Vtg合成的主要器官,在卵黄积累阶段最为活跃,而卵巢Vtg合成水平相对较低。Tilapia feature asynchronous oocyte development and batch spawning. We conducted this study to further understand ovarian maturation and the physiological mechanisms involved in non-synchronous spawners, such as tilapia. Changes in sex steroid hormones（estradiol-17β[E2] and progesterone [P]）, vitellogenin（Vtg） levels, and Vtg mRNA expression were studied during ovarian development in Oreochromis niloticus using histological, enzyme-linked immunoassay, and quantitative reverse transcription-polymerase chain reaction methods, respectively. The results showed that the gonadosomatic index（GSI） of O. niloticus paralleled ovarian development and peaked at stage Ⅴ. Serum E2 levels increased significantly beginning at stage Ⅱ, peaked at stage Ⅳ, then decreased significantly at stage Ⅴ, whereas P levels increased gradually beginning at stage Ⅱ, peaked at stage Ⅴ, and decreased significantly at stage Ⅵ. Hepatic Vtg content increased initially, decreased, and then peaked at stage Ⅳ. Serum and ovarian Vtg contents increased gradually beginning at stage Ⅱ, peaked at stage Ⅴ, and decreased significantly at stage Ⅵ. Hepatic Vtg mRNA expression peaked at stage Ⅲ and decreased gradually atstage Ⅳ. Ovarian Vtg mRNA expression was relatively lower and peaked at stage Ⅴ. These results indicate that E2 and P play different roles during the early and late ovarian developmental stages, respectively. A close correlation was detected between changes in Vtg content in different tissues and ovarian maturation.Vtg mRNA from the liver and ovary were involved in Vtg synthesis; the liver is the major synthetic organ active during the yolk accumulation phase, but ovarian Vtg synthesis was relatively low.We provide some basic data to further explore the endocrine regulatory mechanisms in non-synchronous spawning fish.

关 键 词：尼罗罗非鱼 卵巢发育 性类固醇激素 卵黄蛋白原 Vtg MRNA 

分 类 号：S917.4[农业科学—水产科学]