奥尼罗非鱼及其亲本感染无乳链球菌后生理响应变化  

THE PHYSIOLOGICAL RESPONSE OF HYBRID TILAPIA(OREOCHROMIS NILOTICUS♀×OREOCHROMIS AUREUS♂)AND ITS PARENTS INFECTED WITH STREPTOCOCCUS AGALACTIAE

作　　者：祝璟琳[1,2] 李大宇 邹芝英[1] 肖炜[1] 喻杰[1] 杨弘 薛良义[2] ZHU Jing-Lin;LI Da-Yu;ZOU Zhi-Ying;XIAO Wei;YU Jie;YANG Hong;XUE Liang-Yi(Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization,Ministry of Agriculture and Rural Affairs,Freshwater Fisheries Research Center,Chinese Academy of Fishery Sciences,Wuxi 214081,China;College of Marine Science,Ningbo University,Ningbo 315211,China)

机构地区：[1]中国水产科学研究院淡水渔业研究中心,农业农村部淡水渔业和种质资源利用重点实验室,无锡214081 [2]宁波大学海洋学院,宁波315211

出　　处：《水生生物学报》2021年第6期1190-1200,共11页Acta Hydrobiologica Sinica

基　　金：国家现代农业产业技术体系(CARS-46);中国水产科学研究院淡水渔业研究中心基本科研业务(2021JBFM04);中国水产科学研究院院级基本科研业务费(2020TD37);农业农村部淡水渔业健康养殖重点实验室开放课题(ZJK202012)资助。

摘　　要：研究通过比较杂交子一代奥尼罗非鱼(Oreochromis spp.)与亲本在腹腔注射无乳链球菌(Streptococcus agalactiae)后累积死亡率差异,血液生理指标、生化指标和脾脏促炎性细胞因子的表达水平变化,以深入了解奥尼罗非鱼抗病性杂种优势的生理和分子基础。结果显示:在无乳链球菌人工感染后,奥尼罗非鱼的累积死亡率显著低于亲本(P<0.05)。感染前奥尼罗非鱼的白细胞数、红细胞数和红细胞压积最高,感染后3种罗非鱼的白细胞都显著性升高(P<0.05),红细胞数、红细胞压积和血红蛋白显著性下降(P<0.05),呼吸暴发受到抑制,奥尼罗非鱼血液生理指标与父本奥利亚罗非鱼更为接近;奥尼罗非鱼在感染细菌后的血糖浓度和溶菌酶含量显著高于亲本,呼吸暴发强于亲本(P<0.05)。定量PCR结果显示感染后3种罗非鱼脾脏TNF-α、IL-1β和IL-6的mRNA表达水平都显著上升(P<0.05),3种罗非鱼的TNF-α和IL-6都在感染后7h达到峰值,奥尼罗非鱼IL-1β在感染后48h达到峰值,尼罗罗非鱼IL-1β在感染后24-48h达到峰值,奥利亚罗非鱼IL-1β在感染后72h达到峰值;奥尼罗非鱼的TNF-α和IL-6 mRNA表达水平在感染前后都最高,IL-1βmRNA表达水平在感染前和感染后7-48h显著高于亲本(P<0.05)。研究表明杂交育种途径能显著提高鱼体的抗病力,与亲本相比,奥尼罗非鱼对无乳链球菌的侵染具有更强的防御能力;感染后3种罗非鱼促炎性细胞因子都显著升高,可能参与了宿主对细菌感染的防御,但奥尼罗非鱼的免疫应答比亲本更活跃,表现出抗病力杂种优势。Streptococcosis,caused by Streptococcus agalactiae,seriously harms the Chinese tilapia aquaculture industry.Improving the internal disease resistance of tilapia is a preferred method to control this disease.We observed the physiological responses of hybrid tilapia(Oreochromis niloticus♀×O.aureus♂)and their parents after challenged with pathogenic S.agalactiae.The cumulative mortality was recorded at different time points.Blood and spleen samples were collected at 0,7h,24h,48h,72h,120h and 168h after infection,respectively.Blood physiological and biochemical indexes were measured between hybrid tilapia and its parents.The expression of pro-inflammatory cytokines in spleen were compared to gain an in-depth understanding of the physiological and molecular basis of the disease resistance heterosis.The result showed that the cumulative mortality of hybrid tilapia was significantly lower than its parents.The white blood cell count,red blood cell count and hematocrit of hybrid tilapia were the highest of three tilapias before infection.The white blood cell count increased significantly after infection,whereas hematocrit and hemoglobin decreased significantly.The infection of fish resulted in a strong inhibition of the respiratory burst,and the blood physiological indexes of hybrid tilapia were closer to those of O.aureus.The result showed that the cumulative mortality of hybrid tilapia was significantly lower than their parents.The white blood cell count,red blood cell count and hematocrit of hybrid tilapia were the highest of three tilapias before infection.The white blood cell count increased significantly after infection,whereas hematocrit and hemoglobin decreased significantly.The infection resulted in a strong inhibition of the respiratory burst,and the blood physiological indexes of hybrid tilapia were closer to those of O.aureus.Hybrid tilapia had higher glucose,lysozyme activity and the respiratory burst compared with their parents.The pro-inflammatory cytokines(TNF-α,IL-1βand IL-6)mRNA levels in the sple

关 键 词：奥尼罗非鱼 无乳链球菌 生理响应 促炎性细胞因子 呼吸暴发 

分 类 号：S941[农业科学—水产养殖]