Acute hepatopancreatic necrosis disease (AHPND) is a lethal shrimp disease. The pathogenic agent of this disease is a special Vibrio parahaemolyticus strain that contains a pVA1 plasmid. The protein products of two toxin genes in pVA1, pirA^vp and pirB^vp, targeted the shrimp’s hepatopancreatic cells and were identified as the major virulence factors. However, in addition to pirA^vp and pirB^vp, pVA1 also contains about ~90 other open-reading frames (ORFs), which may encode functional proteins. NCBI BLASTp annotations of the functional roles of 40 pVA1 genes reveal transposases, conjugation factors, and antirestriction proteins that are involved in horizontal gene transfer, plasmid transmission, and maintenance, as well as components of type II and III secretion systems that may facilitate the toxic effects of pVA1-containing Vibrio spp. There is also evidence of a post-segregational killing (PSK) system that would ensure that only pVA1 plasmid-containing bacteria could survive after segregation. Here, in this review, we assess the functional importance of these pVA1 genes and consider those which might be worthy of further study.

中文翻译：

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引起 AHPND 的 pVA1 质粒中重要基因的功能注释综述。

急性肝胰腺坏死病（AHPND）是一种致命的虾病。该病的病原体是一种特殊的副溶血性弧菌菌株，含有pVA1质粒。pVA1 中的两个毒素基因pirA ^vp和 pirB ^vp的蛋白质产物靶向虾的肝胰腺细胞，并被确定为主要毒力因子。然而，除了pirA ^vp和 pirB ^vp之外，pVA1 还包含约 90 个其他开放阅读框 (ORF)，它们可能编码功能蛋白。NCBI BLASTp 对 40 个 pVA1 基因功能作用的注释揭示了参与水平基因转移、质粒传输和维持的转座酶、接合因子和抗限制蛋白，以及可能促进毒性作用的 II 型和 III 型分泌系统的组件含有 pVA1 的弧菌属的影响。还有证据表明，分离后杀伤（PSK）系统将确保只有含有 pVA1 质粒的细菌才能在分离后存活。在这篇综述中，我们评估了这些 pVA1 基因的功能重要性，并考虑了那些可能值得进一步研究的基因。