Institute for Integrative Systems Biology, Universitat de València and Consejo Superior de Investigaciones Científicas, València 46980, Spain.
Institut Cavanilles de Biodiversitat i Biologia Evolutiva, Universitat de València, València 46980, Spain.
Proc Natl Acad Sci U S A. 2024 Nov 5;121(45):e2415631121. doi: 10.1073/pnas.2415631121. Epub 2024 Oct 29.
Reverse-transcribing animal DNA viruses include the hepadnaviruses, a well-characterized family of small enveloped viruses that infect vertebrates but also a sister group of nonenveloped viruses more recently discovered in fish and termed the nackednaviruses. Here, we describe the complete sequence of a virus found in the feces of an insectivorous bat, which encodes a core protein and a reverse transcriptase but no envelope protein. A database search identified a viral sequence from a permafrost sample as its closest relative. The two viruses form a cluster that occupies a basal phylogenetic position relative to hepadnaviruses and nackednaviruses, with an estimated divergence time of 500 My. These findings may lead to the definition of a "proto-nackednavirus" family and support the hypothesis that the ancestors of hepadnaviruses were nonenveloped.
逆转录动物 DNA 病毒包括正肝病毒，这是一类已充分研究的小型包膜病毒，感染脊椎动物，但也是最近在鱼类中发现的、无包膜病毒的姐妹群，被称为裸病毒。在这里，我们描述了一种在食虫蝙蝠粪便中发现的病毒的完整序列，该病毒编码核心蛋白和逆转录酶，但没有包膜蛋白。数据库搜索确定了一种来自永久冻土样本的病毒序列，它是该病毒最接近的亲缘。这两种病毒形成一个聚类，相对于正肝病毒和裸病毒处于系统发育的基础位置，估计它们的分化时间为 5 亿年。这些发现可能会导致“原始裸病毒”家族的定义，并支持正肝病毒的祖先为无包膜的假说。
