A Highly Prevalent and Pervasive Densovirus Discovered among Sea Stars from the North American Atlantic Coast
A Highly Prevalent and Pervasive Densovirus Discovered among Sea Stars from the North American Atlantic Coast
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DOI：
10.1128/aem.02723-19
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发表时间：
2020-03-01
影响因子：
4.4
通讯作者：
Hewson, Ian
中科院分区：
文献类型：
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作者：
Jackson, Elliot W.;Pepe-Ranney, Charles;Hewson, Ian
海星星星消耗综合征的病因被假设是由浓核病毒引起的，海星相关浓核病毒（SSaDV），以前曾在美国的太平洋和大西洋沿岸报道过。在这项研究中，我们重新评估了来自北美大西洋海岸的海星中SSaDV的存在，并在此过程中发现了一种新的浓核病毒，我们将其命名为Asterias forbesi-associated densovirus（AfaDV），与SSaDV具有78%的核苷酸配对同一性。与以前的研究相比，在北美大西洋沿岸的海星中没有检测到SSaDV。使用各种PCR为基础的技术，我们调查了组织嗜性，宿主特异性，和流行的海星种群之间的AfaDV在沿着大西洋海岸的五个地点。在3种星星（Asterias forbesi、Asterias rubens和Henricia sp.）在该地区发现，并且在抽样人群中高度流行（>80%的受试个体; n = 134）。AfaDV检测到体壁，性腺和幽门盲囊（消化腺）的标本，但没有检测到体腔液。不同组织类型之间的病毒载量（拷贝数mg（-1））存在显著差异，幽门盲囊的病毒载量最高。对小海星性腺组织的进一步研究发现，生殖系细胞（卵母细胞）呈病毒阳性，这表明存在潜在的垂直传播途径。综上所述，这些观察结果表明，AfaDV的存在并不是海星星星消耗综合征的指标，因为不管健康状况如何，AfaDV都是这些动物微生物组的常见成分。重要信息海星星星消耗综合征是一种主要在北美太平洋和大西洋海岸观察到的疾病，对海星星星种群有显著影响。这种疾病的病因尚不清楚，尽管假设是由浓核病毒SSaDV引起的。但此前的研究尚未发现SSaDV与北美大西洋沿岸海星星星消耗综合征之间的相关性。这项研究表明，这一观察结果可能是由于存在一种遗传相似的浓核病毒AfaDV，这可能混淆了以前的研究。SSaDV在本研究筛选的海星中不存在，相反，AfaDV在整个新英格兰地区的海星星星种群中普遍存在，没有明显的疾病迹象。这些结果表明，海星星星浓核病毒可能是动物微生物组的常见组成部分，这些病毒在野生种群中的多样性和范围可能比以前认识到的要大。
The etiology of sea star wasting syndrome is hypothesized to be caused by a densovirus, sea star-associated densovirus (SSaDV), that has previously been reported on the Pacific and Atlantic Coasts of the United States. In this study, we reevaluated the presence of SSaDV among sea stars from the North American Atlantic Coast and in doing so discovered a novel densovirus that we have named Asterias forbesi-associated densovirus (AfaDV), which shares 78% nucleotide pairwise identity with SSaDV. In contrast to previous studies, SSaDV was not detected in sea stars from the North American Atlantic Coast. Using a variety of PCR-based techniques, we investigated the tissue tropism, host specificity, and prevalence of AfaDV among populations of sea stars at five locations along the Atlantic Coast. AfaDV was detected in three sea star species (Asterias forbesi, Asterias rubens, and Henricia sp.) found in this region and was highly prevalent (>80% of individuals tested; n = 134), among sampled populations. AfaDV was detected in the body wall, gonads, and pyloric caeca (digestive gland) of specimens but was not detected in their coelomic fluid. A significant difference in viral load (copies mg(-1)) was found between tissue types, with the pyloric caeca having the highest viral loads. Further investigation of Asterias forbesi gonad tissue found germ line cells (oocytes) to be virus positive, suggesting a potential route of vertical transmission. Taken together, these observations show that the presence of AfaDV is not an indicator of sea star wasting syndrome because AfaDV is a common constituent of these animals' microbiome, regardless of health.IMPORTANCE Sea star wasting syndrome is a disease primarily observed on the Pacific and Atlantic Coasts of North America that has significantly impacted sea star populations. The etiology of this disease is unknown, although it is hypothesized to be caused by a densovirus, SSaDV. However, previous studies have not found a correlation between SSaDV and sea star wasting syndrome on the North American Atlantic Coast. This study suggests that this observation may be explained by the presence of a genetically similar densovirus, AfaDV, that may have confounded previous studies. SSaDV was not present in sea stars screened in this study, and instead, AfaDV was commonly found in sea star populations across the New England region, with no apparent signs of disease. These results suggest that sea star densoviruses may be common constituents of the animals' microbiome, and the diversity and extent of these viruses among wild populations may be greater than previously recognized.