| 摘要: |
| 性类固醇激素对动物生长有一定的影响, 但其对鱼类雌、雄生长差异的影响机理尚不清楚。 为进一步了解动物雌雄生长差异的内在原因, 本文通过在体注射和荧光定量PCR 方法, 比较了性类 固醇激素(E2、MT)对尼罗罗非鱼雌鱼和雄鱼的生长及对垂体GH、肝脏GHR1、IGF-I mRNA 表达的 影响。结果表明: 性类固醇激素E2 和MT 对尼罗罗非鱼的生长及生长轴相关基因的表达均有显著的 影响, 并且这种影响存在明显的性别二态性。E2 明显促进雌鱼的生长但不显著影响雄鱼的生长, MT 显著促进雄鱼和雌鱼的生长; E2 可使雌鱼垂体GH 和肝脏GHR1 、IGF-I 的mRNA 水平显著升高 (P<0.05), 但降低雄鱼垂体GH和肝脏GHR1的mRNA表达; MT 显著提高雄鱼垂体GH和肝脏GHR1、 IGF-I mRNA 水平(P<0.05), 但降低雌鱼垂体GH 的mRNA 表达, 促进雌鱼肝脏GHR1 mRNA 的表达, 但对雄鱼肝脏GHR1 的促进作用明显大于雌鱼(P<0.05).上述结果表明, 性类固醇激素对不同性别尼 罗罗非鱼的生长及生长轴相关基因的mRNA 表达有不同的影响, 表现出明显的性别二态性, 提示不 同性别鱼体内性类固醇激素水平的不同可能是导致尼罗罗非鱼雌雄生长二态性的另一内在原因。 |
| 关键词: 尼罗罗非鱼 E2 MT 雌雄生长差异 基因表达 |
| DOI：10.11693/hyhz20150900241 |
| 分类号: |
| 基金项目:国家自然科学基金项目, 31201978 号; 惠州学院自然科学重点项目, 2012ZD07 号。 |
附件 |
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| STEROID HORMONES (E2 AND MT) DISPLAYED DIFFERENCE IN SEX FOR NILE TILAPIA OREOCHROMIS NILOTICUS |
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MA Xi-Lan1, ZHANG Yong2, CHEN Yong-Zhi1, ZHOU Li-Bin1
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1.Department of Life Science, Huizhou University and Institute of Biotechnology, Huizhou 516007, China;2.State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
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| Abstract: |
| Steroid hormone affects the growth of fish sexual dimorphism, and the mechanism remains unclear. Nile tilapia (Oreochromis niloticus) is a fresh water fish with obvious sexual dimorphism. The effects of steroid hormone on the growth and expressions of GH in pituitary, GHR and IGF-I mRNA in liver of Nile tilapia were studied. Two experiments in a long and short period were designated and carried out. In the long-period experiment, 200 fish individuals in similar body size were randomly assigned into the control group [intraperitoneal injection (i. p.) with fish physiological saline, PS], the E2 group (i. p. with E2, 50μg/g body weight), and the MT group (i. p. with MT, 50μg/g body weight), and fed for 70 days under the same natural conditions. Result shows that E2 significantly promoted female growth and enhanced female GH, GHR1, and IGF-I mRNA expressions (P<0.05), but for males not in growth nor GH, GHR1 mRNA expressions. However, MT boosted significantly the growth of both sexes. MT improved GH for males, and GHR1 expressions for both sexes but greater in male than in female (P<0.05). Therefore, steroid hormones affected the growth and the genes expression in different ways in sex, which may become a reason for the dimorphism of the fish. |
| Key words: Nile tilapia (Oreochromis niloticus) E2 MT sexual dimorphism gene expression |
