水生生物学报2013，Vol.37Issue(1)：42-47,6.DOI:10.7541/2013.42
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
摘要
Abstract
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 u.g/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 hepa-tosomatic 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 (P<0.05). During the 0-2, 2-6, and 6-10 weeks, SGR-w 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 (P<0.05); 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 (P<0.05). Furthermore, CF and HIS levels of the LHRH-A group were also significantly higher than those of the control group (P<0.05). 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-A group (intraperitoneal injection with LHRH-A, 0.01 u.g/g body weight) and sampled at 6, 12, 24h, and 2 week. Real-time quantitative PCR was used to detect the expressions of GH in pituitary and GHR and IGF-I in liver at different life stages after injection. The expressions of GH in pituitary increased at 12h (P<0.05), and IGF-I in liver increased quickly at 6h, but soon returned to the level of control group. The expression of GHR in liver increased slowly at 24h (P<0.05) and maintained high at 2 week (PO.01). The results indicated that LHRH-A could increase the mRNA expressions of GH in pituitary and GHR and IGF-I in liver, and significantly promote growth of Nile tilapia. Moreover, our study suggested that large scale administration of some neruoendocrine factor in diet to accelerate the growth rate of cultured fish has promising potential.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Key words
Nile tilapia Oreochromis niloticus/ LHRH-A/ Growth/ Gene expression分类
生物科学引用本文复制引用
马细兰,张勇,周立斌,刘晓春,林浩然..LHRH-A对尼罗罗非鱼生长及生长轴相关基因表达的影响[J].水生生物学报,2013,37(1):42-47,6.基金项目
国家重点基础研究发展计划(973计划)项目(2010CB126302) （973计划）
广东省自然科学基金项目(9451601501001986) （9451601501001986）
广东省教育部产学研结合项目(2010B090400551)资助 （2010B090400551）
