Namao virus (NV) is a sturgeon nucleocytoplasmic large DNA virus (sNCLDV) that can cause a lethal disease of the integumentary system in lake sturgeon Acipenser fulvescens. As a group, the sNCLDV have not been assigned to any currently recognized taxonomic family of viruses. In this study, a data set of NV DNA sequences was generated and assembled as two non-overlapping contigs of 306,448 bp and then used to conduct a comprehensive systematics analysis using Bayesian inference of phylogeny for NV, other sNCLDV and representative members of six families of the NCLDV superfamily. The phylogeny of NV was reconstructed using protein homologues encoded by nine nucleocytoplasmic virus orthologous genes (NCVOGs): NCVOG0022 – mcp, NCVOG0038 – DNA polymerase B elongation subunit, NCVOG0076 – VV A18-type helicase, NCVOG0249 – VV A32-type ATPase, NCVOG0262 – AL2 VLTF3-like transcription factor, NCVOG0271 – RNA polymerase II subunit II, NCVOG0274 – RNA polymerase II subunit I, NCVOG0276 – ribonucleotide reductase small subunit and NCVOG1117 – mRNA capping enzyme. The accuracy of our phylogenetic method was evaluated using a combination of Bayesian statistical analysis and congruence analysis. Stable tree topologies were obtained with data sets differing in target molecule(s), sequence length and taxa. Congruent topologies were obtained in phylogenies constructed using individual protein data sets. The major capsid protein phylogeny inferred that ten representative sNCLDV form a monophyletic group comprised of four lineages within a polyphyletic Mimi-Phycodnaviridae group of taxa. Overall, the analyses revealed that Namao virus is a member of the Mimiviridae family with strong and consistent support for a clade containing NV and CroV as sister taxa.

Namao病毒（NV）为核质鲟大DNA病毒（sNCLDV），其可导致皮肤系统的致死性疾病中湖鲟鲟针毛。作为一个整体，尚未将sNCLDV分配给任何当前公认的病毒分类学家族。在这项研究中，NV DNA序列的数据集被生成并组装为两个非重叠的306,448 bp重叠群，然后使用贝叶斯系统推断对NV，其他sNCLDV和六个家族的代表性成员进行了全面的系统分析。 NCLDV超家族。NV的系统进化是使用由9个核质病毒直系同源基因（NCVOGs）编码的蛋白质同源物重建的：NCVOG0022 – mcp，NCVOG0038 – DNA聚合酶B延伸亚基，NCVOG0076 – VA A18型解旋酶，NCVOG0249 – VA A32型ATPase，NCVOG026 AL2类VLTF3样转录因子，NCVOG0271 – RNA聚合酶II亚基II，NCVOG0274 – RNA聚合酶II亚基I，NCVOG0276 –核糖核苷酸还原酶小亚基，NCVOG1117 – mRNA封端酶。我们结合贝叶斯统计分析和一致性分析来评估我们的系统发育方法的准确性。使用目标分子，序列长度和分类单元不同的数据集获得了稳定的树形拓扑。在使用个体蛋白质数据集构建的系统发育中获得了一致的拓扑。主要衣壳蛋白系统发生学推断，十个代表性的sNCLDV形成了由多系内的四个谱系组成的单系群 在使用个体蛋白质数据集构建的系统发育中获得了一致的拓扑。主要衣壳蛋白系统发生学推断，十个代表性的sNCLDV形成了由多系内的四个谱系组成的单系群 在使用个体蛋白质数据集构建的系统发育中获得了一致的拓扑。主要衣壳蛋白系统发生学推断，十个代表性的sNCLDV形成了由多系内的四个谱系组成的单系群类群的咪咪-Phycodnaviridae组。总体而言，分析表明，Namao病毒是Mimiviridae家族的成员，对含有NV和CroV作为姊妹类群的进化枝有坚定而一致的支持。