Ⅱ型草鱼呼肠孤病毒在稀有鮈鲫中的传播途径  

Transmission routes of grass carp reovirus typeⅡin rare minnow Gobiocypris rarus

作　　者：倪秦伟 孙阳 刘林怡 吕利群[2] NI Qinwei;SUN Yang;LIU Linyi;LYU Liqun(National Pathogen Collection Center for Aquatic Animals,Shanghai Ocean University,Shanghai 201306,China;Key Laboratory of Agriculture Ministry for Freshwater Aquatic Genetic Resources,Shanghai Ocean University,Shanghai 201306,China)

机构地区：[1]上海海洋大学,国家水生动物病原库,上海201306 [2]上海海洋大学,农业农村部淡水水产种质资源与利用重点实验室,上海201306

出　　处：《水产学报》2024年第5期139-148,共10页Journal of Fisheries of China

基　　金：国家现代农业产业技术体系建设专项(CARS-45-16)。

摘　　要：为了研究Ⅱ型草鱼呼肠孤病毒(GCRV-Ⅱ)的流行规律,本实验基于稀有鮈鲫感染GCRV-JX02的研究模型,利用分子生物学检测、逆转录实时定量聚合酶链式反应(RTqPCR)等方法开展GCRV-Ⅱ水平和垂直传播的研究。结果显示,水平传播中浸泡感染和共培养感染都能使稀有鮈鲫成为GCRV-Ⅱ的无症状携带者,阳性检出率分别为50%和80%;其中共培养感染直接导致8%的稀有鮈鲫死亡。感染后无症状的稀有鮈鲫经热休克处理,浸泡感染与共培养感染组的死亡率分别为57.14%和100%,总体阳性检出率分别为80.95%和100%。腹腔注射感染GCRV-JX02后存活的无症状稀有鮈鲫每0.01 g精巢与卵巢中病毒拷贝数分别为3.64×10^(6)和6.84×10^(6)个。垂直传播实验中稀有鮈鲫单个的卵子、未受精卵、受精卵和幼鱼的平均病毒拷贝数为1.98×10^(3)、1.15×10^(4)、4.75×10^(3)和6.74×10^(4)个,幼鱼中病毒的拷贝数显著高于卵子与受精卵时期,表明GCRV-JX02不仅能够在稀有鮈鲫中垂直传播,还能伴随幼鱼的发育不断扩增。本研究阐明了不同传播途径下GCRV-Ⅱ的传播潜力,有助于评估草鱼出血病的流行风险,且为筛选阻断草鱼呼肠孤病毒传播的药物提供了有效的动物模型。Grass carp reovirus(GCRV)causes severe grass carp hemorrhagic disease,which is one of the main diseases that threaten grass carp culture in our country.In order to explore the transmission of grass carp reovirus typeⅡ(GCRV-Ⅱ),we established the horizontal and vertical transmission models of GCRV-JX02 infection in rare minnow Gobiocypris rarus using molecular biology detection and real-time fluorescent quantitative(RTqPCR)methods.We compared the transmission efficiency of GCRV-JX02 in different models,and found that immersion infection and co-culture infection could turn the rare minnow into asymptomatic carriers of GCRVJX02 in horizontal transmission.The positive detection rates were 50%and 80%,while the mortality rates of rare minnow in co-culture infection were 8%.When the asymptomatic rare minnow in the immersion and co-culture groups were treated with heat shock,the mortality rates were 57.14%and 100%,and the overall positive detection rates were 80.95%and 100%.Copy numbers of GCRV-JX02 in the testis and ovary of asymptomatic rare minnow after being injected intraperitoneally of GCRV-JX02 were 3.64×10^(6) and 6.84×10^(6) copies/0.01g.In the vertical transmission experiment,average copy numbers of GCRV-JX02 in ova,unfertilized eggs,fertilized eggs and juvenile fish were 1.98×10^(3),1.15×10^(4),4.75×10^(3) and 6.74×10^(4) copies.The copy number of GCRV-JX02 in single juvenile fish was significantly higher than that of ovum and fertilized egg.The results indicated that GCRV-JX02 could not only transmit vertically in rare minnow,but also persist continuously with the development of juvenile fish.This study elucidates the transmission efficiency of GCRV-Ⅱin multiple transmission routes,which is helpful in evaluating the epidemic risk of grass carp hemorrhagic disease and provide an effective animal model for screening drugs to block the transmission of GCRV.

关 键 词：稀有鮈鲫 草鱼呼肠孤病毒 水平传播 垂直传播 热休克处理 

分 类 号：S943[农业科学—水产养殖]