College of Marine Sciences, South China Agricultural University, Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China.
Guangdong Winsun Biological Pharmaceutical Co., Ltd., Guangzhou, 511356, China.
Fish Shellfish Immunol. 2023 Oct;141:109034. doi: 10.1016/j.fsi.2023.109034. Epub 2023 Aug 26.
The spotted knifejaw (Oplegnathus punctatus) has recently emerged as a highly economically significant farmed fish in China. However, due to increasing environmental pollution and breeding density, a range of infectious diseases, including the iridovirus pathogen, have begun to spread widely. In this study, we isolated and identified a strain of Megalocytivirus, SKIV-TJ, from cultured spotted knifejaw in Tianjin, China. We observed significant cytopathic effects (CPE) in SKIV-TJ-infected spotted knifejaw brain (SKB) cells, and electron microscopy showed numerous virus particles in the cytoplasm of SKB cells 6 days post-infection. The annotated complete genome of SKIV-TJ (GenBank accession number ON075463) contained 112,489 bp and 132 open reading frames. Based on the multigene association evolutionary tree using 26 iridovirus core genes, SKIV-TJ was found to be most closely related to Rock bream iridovirus (RBIV). Cumulative mortality of spotted knifejaw infected with SKIV-TJ reached 100% by day 9. A transcriptomic analysis were conducted and a total of 5517 differentially expressed genes were identified, including 2757 upregulated genes and 2760 downregulated genes. The upregulated genes were associated with viral infection and immune signaling pathways. Our findings provide a valuable genetic resource and a deeper understanding of the immune response to SKIV infection in spotted knifejaw.
斑点刀额鲈（Oplegnathus punctatus）最近已成为中国极具经济重要性的养殖鱼类。然而，由于环境污染和养殖密度的增加，一系列传染性疾病，包括虹彩病毒病原体，开始广泛传播。在这项研究中，我们从中国天津养殖的斑点刀额鲈中分离并鉴定了一株 Megalocytivirus，命名为 SKIV-TJ。我们观察到 SKIV-TJ 感染的斑点刀额鲈脑（SKB）细胞出现明显的细胞病变效应（CPE），电镜显示 SKB 细胞感染后 6 天细胞质中存在大量病毒颗粒。SKIV-TJ 的全基因组（GenBank 登录号 ON075463）全长 112489bp，包含 132 个开放阅读框。基于使用 26 个虹彩病毒核心基因构建的多基因关联进化树，SKIV-TJ 与石斑鱼虹彩病毒（RBIV）亲缘关系最近。感染 SKIV-TJ 的斑点刀额鲈在第 9 天的累积死亡率达到 100%。我们进行了转录组分析，共鉴定出 5517 个差异表达基因，包括 2757 个上调基因和 2760 个下调基因。上调基因与病毒感染和免疫信号通路有关。我们的研究结果为斑点刀额鲈提供了有价值的遗传资源，并深入了解了其对 SKIV 感染的免疫反应。
