【作者】 朱凡； 叶恒振； 王海洋； 周智； 骆剑； 陈国华；

【Author】 Zhu Fan;Ye Hengzhen;Wang Haiyang;Zhou Zhi;Luo Jian;Chen Guohua;State Key Laboratory of Marine Resource Utilization in South China Sea, Key Laboratory of Tropical Biological Resources of Ministry of Education, Hainan University;

【机构】 海南大学南海海洋资源利用国家重点实验室热带生物资源教育部重点实验室；

【摘要】 温度对于鱼类来说是最重要的外界环境因素,在前期实验中发现,在温度差异条件下,布氏鲳鯵表现出生长差异,同时其GHRHR基因在多组织中呈现显著的差异。为研究不同温度对布氏鲳鯵生长的影响,本实验设计四个温度梯度,水温分别为21℃、25℃、29℃、33℃。实验结果表明,不同水温环境条件下的幼鱼有不同的生长速度,在21℃-33℃的范围内,随着温度升高,幼鱼特定生长率(SGR)随之升高,利用二次方程拟合SGR和温度的关系:SGR=(-0.019)T2+1.245T-15.51(P<0.05,R~2=0.997),计算得到SGR在32.76℃达到最大值;饵料系数(FC)随着温度升高而显著降低,利用二次方程拟合FC和温度的关系:FC=(0.004)T2-0.255T+5.046(P<0.05,R~2=0.999)计算得到FC在31.86℃达到最小值;摄食率(FR)随着温度的升高而升高,回归曲线表明在33.75℃达到最大值。采用荧光实时定量PCR检测了GHRHR转录本的组织分布及其在不同温度下的表达变化。布氏鲳鲹GHRHR基因的表达区域大多都在中枢神经系统,肝脏、肠和性腺也有表达,其中性腺表达量最高,其他组织中没有检测到GHRHR基因的表达。在不同温度下,GHRHR m RNA的表达受到了影响,低温组21℃和高温组33℃时GHRHR基因的表达量最低,在温度组29℃表达量最高(P<0.05)。温度影响着布氏鲳鯵幼鱼的生长和摄食,同样也影响GHRHR的表达变化。本实验为进一步研究GHRHR基因与鱼类的生长关系提供理论基础。更多还原

【Abstract】 Temperature is the most important external environmental factor for fish. Through former researches, the growth of Trachinotus blochii exists obviously difference due to temperature difference,and its GHRHR genes also exhibit significant difference in multiple tissues. In order to explore the effects of temperature on the growth of T.blochii,this thesis intends to study its juvenile fish in the circulating water system controlled by four water temperature levels of 21,25,29 and 33℃.Experimental results show that juvenile fish had different growth rates under different water temperature conditions. Specific growth rate(SGR)of juvenile rised with the increase of temperature in the rang of 21℃-33℃,and the quadratic equation fitting relations between temperature and SGR was SGR=(-0.019)T~2 + 1.245T-15.51( P < 0.05,R~2=0.997),which demonstrated that the maximum SGR was at 32.76℃. The feed coefficient(FC)decreased significant with the increase of temperature,using the quadratic equation fitting relations between temperature and FC:FC=(0.004)T~2-0.255 T +5.046( P < 0.05,R~2=0.999),and the minimum FC was at 31.86℃. Feeding rate(FR)increases with the increasing of temperature,regression curve show that the maximum value was at 33.75℃.The tissue distribution of GHRHR transcripts and the gene expression at different temperatures were detected by real-time fluorescence quantitative PCR. The expression region of T.blochii GHRHR gene were mostly in the central nervous system,The liver, intestine and gonadal are also expressed, in which the gonadal expression was the highest,it was not detected in the other tissue.The expression level of GHRHR m RNA changed significantly at different temperatures.The lowest expression level was observed in the temperature group at 21℃ and 33℃,but the highest expression level was observed in the temperature group at 29℃.Temperature affects the growth and feeding of T.blochii juvenile, and also influence the expression of GHRHR gene. This study provides a theoretical basis for further study of the relationship between GHRHR gene and fish growth.更多还原