Department of Microbiology, Cornell University, Ithaca, NY 14850, USA.
New Visions Life Sciences, Boards of Cooperative Educational Services of New York State, Ithaca, NY 14850, USA.
Viruses. 2017 Nov 26;9(12):361. doi: 10.3390/v9120361.
Aquatic invertebrates are common reservoirs of a rapidly expanding group of circular Rep-encoding ssDNA (CRESS-DNA) viruses. This study identified and explored the phylogenetic relationship between novel CRESS-DNA viral genotypes associated with Pacific intertidal isopods , , and . One genotype associated with , IWaV278, shared sequence similarity and genomic features with Tombusviridae (ssRNA) and Circoviridae (ssDNA) genomes and was putatively assigned to the Cruciviridae clade comprising chimeric viruses. The complete genome of IWaV278 (3478 nt) was computationally completed, validated via Sanger sequencing, and exhibited sequence conservation and codon usage patterns analogous to other members of the Cruciviridae. Viral surveillance (qPCR) indicated that this virus was temporally transient (present in 2015, but not 2017), specific to at a single collection site (Washington, DC, USA), more prevalent among male specimens, and frequently detected within exoskeletal structures. 18S rRNA sequences identified two alveolate protists associated with IWaV278-positive tissues and mechanical epibiont removal of ciliated exoskeletal structures eliminated viral detection, suggesting that the putative host of IWaV278 may be an epibiont of . This investigation provides additional phylogenetic evidence to resolve Cruciviridae evolution and offers insight into the biogeography, specificity, and potential host of a crucivirus genotype.
水生无脊椎动物是快速扩张的环形 Rep 编码 ssDNA (CRESS-DNA) 病毒的常见储主。本研究鉴定并探讨了与太平洋潮间带等足类动物有关的新型 CRESS-DNA 病毒基因型的系统发育关系。与 相关的一种基因型 IWaV278 与 Tombusviridae(ssRNA)和 Circoviridae(ssDNA)基因组具有相似的序列相似性和基因组特征,并被推测属于包含嵌合病毒的 Cruciviridae 分支。IWaV278 的完整基因组(3478nt)通过计算完成,通过 Sanger 测序进行验证,表现出与 Cruciviridae 其他成员相似的序列保守性和密码子使用模式。病毒监测(qPCR)表明,该病毒具有时间上的瞬时性(2015 年存在,但 2017 年不存在),仅在单一采集点(美国华盛顿特区)特异性存在于 中,在雄性标本中更为普遍,并且经常在外骨骼结构中检测到。18S rRNA 序列鉴定出与 IWaV278 阳性组织相关的两种有孔虫原生动物,并通过机械性地去除纤毛外骨骼结构的附生生物,消除了病毒的检测,表明 IWaV278 的假定宿主可能是 IWaV278 的附生生物。本研究提供了额外的系统发育证据来解决 Cruciviridae 的进化问题,并深入了解了一种 Cruciviridae 基因型的生物地理学、特异性和潜在宿主。