LHRH-A对尼罗罗非鱼生长及生长轴相关基因表达的影响  

EFFECTS OF LHRH-A ON THE GROWTH AND GENE EXPRESSIONS OF THE GROWTH AXIS IN NILE TILAPIA OREOCHROMIS NILOTICUS

作　　者：马细兰[1,2,3] 张勇[1] 周立斌[3] 刘晓春[1] 林浩然[1] 

机构地区：[1]中山大学有害生物控制与资源利用国家重点实验室,生命科学学院,水生经济动物研究所暨广东省水生经济动物良种繁育重点实验室,广州510275 [2]华南师范大学生命科学学院,广州510631 [3]惠州学院生命科学系,生物技术研究所,惠州516007

出　　处：《水生生物学报》2013年第1期42-47,共6页Acta Hydrobiologica Sinica

基　　金：国家重点基础研究发展计划(973计划)项目(2010CB126302);广东省自然科学基金项目(9451601501001986);广东省教育部产学研结合项目(2010B090400551)资助

摘　　要：促性腺激素释放激素(GnRH)的主要作用是刺激脑垂体促性激素(GtH)的释放,亦可促进鱼类生长激素(GH)的释放。促黄体素释放激素类似物(LHRH-A)是哺乳类GnRH的类似物,为了分析LHRH-A对尼罗罗非鱼生长调节的作用,设计了长期和短期2个实验,采用腹腔注射(剂量0.1μg/g体重)方法,分析LHRH-A对尼罗罗非鱼绝对生长率、特定生长率、肝体系数和肥满度的影响,并应用荧光实时定量PCR方法检测在注射LHRH-A后不同时段(6h、12h、24h、2周)尼罗罗非鱼垂体GH、肝脏GHR和肝脏IGF-I基因的表达变化。结果表明,LHRH-A组尼罗罗非鱼的绝对生长率、特定生长率、肝体系数、肥满度均显著高于对照组(P<0.05);注射LHRH-A后12h、24h垂体GH mRNA表达水平均显著升高(P<0.05),2周后恢复到对照组水平;注射LHRH-A后24h和2周肝脏GHR mRNA表达水平显著上升(P<0.05);注射LHRH-A后6h肝脏IGF-I mRNA表达水平显著升高(P<0.05),12h、24h和2周恢复到对照组水平。以上结果提示,LHRH-A可显著上调尼罗罗非鱼生长轴相关基因的表达,从而促进鱼类的生长。Regulations of synthesis and secretion of growth hormone（GH） in teleosts are based on the dual control of hypothalamic stimulators including gonadotropin-releasing hormone（GnRH）,dopamine（DA）,and growth hormone-releasing hormone（GHRH）,and hypothalamic inhibitors including somatostatin（SS） and norepinephrine（NE）.Gonadotropin-releasing hormone（GnRH） can stimulate the release of growth hormone（GH）.LHRH-A is an analog of mammalian GnRH.Nile tilapia（Oreochromis niloticus）,a freshwater fish with sexual dimorphism.The effects of LHRH-A on the growth and expressions of GH,GHR and IGF-I mRNA in Nile tilapia remain unclear.Two experiments,designated as long-term and short-term experiments,were carried out.In the long-term experiment,two hundreds Nile tilapias of similar body weight were randomly assigned to the control group（intraperitoneal injection with phosphate saline） and the LHRH-A group（intraperitoneal injection with LHRH-A,0.01 μg/g body weight） and fed under the same conditions for 70 days.The absolute growth rates（AGR）,specific growth rates（SGR）,condition factor（CF） and hepatosomatic index（HSI） were obtained by measuring the body length,body weight and hepatic weight at different stages.AGRW and AGRL levels of LHRH-A-treated male and female increased by 15.95%,14.82% and 5.06%,25.36%,respectively,compared to control group（P0.05）.During the 0—2,2—6,and 6—10 weeks,SGRW and AGRL levels of LHRH-A-treated male increased by 11.52%,1.21%,39.06% and 3.94%,1.08%,10.00%,respectively,compared to the control group（P0.05）;similarly,SGRW and AGRL levels of LHRH-A-treated female increased by 14.29%,6.88%,5.83% and 24.19%,9.09%,28.21%,respectively（P0.05）.Furthermore,CF and HIS levels of the LHRH-A group were also significantly higher than those of the control group（P0.05）.In the short-term experiment,120 Nile tilapias of similar body weight were randomly assigned to the control group（intraperitoneal injection with phosphate saline） and the LHRH

关 键 词：尼罗罗非鱼 促黄体素释放激素类似物 生长 基因表达 

分 类 号：Q344[生物学—遗传学]