Bowers Holly A, Messick Gretchen A, Hanif Ammar, Jagus Rosemary, Carrion Lee, Zmora Oded, Schott Eric J
Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, Baltimore, Maryland 21202, USA.
Dis Aquat Organ. 2010 Dec 7;93(1):17-29. doi: 10.3354/dao02280.
Mortality among blue crab Callinectes sapidus in soft shell production facilities is typically 25% or greater. The harvest, handling, and husbandry practices of soft shell crab production have the potential to spread or exacerbate infectious crab diseases. To investigate the possible role of viruses in soft shell crab mortalities, we took advantage of the physicochemical properties of double-stranded RNA (dsRNA) to isolate a putative virus genome. Further characterization confirmed the presence of a reo-like virus that possesses 12 dsRNA genome segments. The virus was present in >50% of dead or dying soft shell crabs, but fewer than 5% of healthy hard crabs. Injection of the virus caused mortality and resulted in the appearance of viral RNA and virus inclusions in hemocytes. The genome of the virus was partially sequenced and the information used to develop a reverse transcription polymerase chain reaction (RT-PCR) assay that is able to detect the virus genome in as little as 7.5 pg of total RNA. The molecular tools developed during this study will allow us to quantify prevalence of the blue crab reo-like virus in captive (soft shell facilities, aquaculture operations) and wild populations and facilitate understanding of the role this virus has in blue crab life history.
在软壳蟹生产设施中，青蟹（Callinectes sapidus）的死亡率通常达到25%或更高。软壳蟹生产过程中的收获、处理及养殖操作有可能传播或加剧传染性蟹病。为了调查病毒在软壳蟹死亡事件中可能扮演的角色，我们利用双链RNA（dsRNA）的物理化学特性分离出一个假定的病毒基因组。进一步的特征分析证实存在一种类似呼肠孤病毒的病毒，其拥有12个dsRNA基因组片段。该病毒存在于超过50%的死亡或濒死软壳蟹中，但在健康硬壳蟹中的比例不到5%。注射该病毒会导致死亡，并在血细胞中出现病毒RNA和病毒包涵体。对该病毒的基因组进行了部分测序，并利用这些信息开发了一种逆转录聚合酶链反应（RT-PCR）检测方法，该方法能够在仅7.5 pg的总RNA中检测到病毒基因组。在本研究中开发的分子工具将使我们能够量化青蟹类呼肠孤病毒在圈养环境（软壳蟹设施、水产养殖作业）和野生种群中的流行情况，并有助于了解该病毒在青蟹生活史中所起的作用。
