Watermelon crinkle leaf-associated virus 1 and watermelon crinkle leaf-associated virus 2 (WCLaV-1 and WCLaV-2), two unclassified members of the order Bunyavirales, are phylogenetically related to members of the genus Coguvirus (family Phenuiviridae). The genome of both viruses was reported previously to be composed of three RNA segments. However, the terminal sequences of two genomic RNA segments, namely those encoding the putative movement protein (MP) and the nucleocapsid (NP) protein, remained undetermined. High-throughput sequencing of total RNA and small RNA preparations, combined with reverse transcription PCR amplification followed by sequencing, revealed that the WCLaV-1 and WCLaV-2 possess a bipartite genome consisting of a negative-sense RNA1, encoding the RNA-dependent RNA polymerase, and an ambisense RNA2, encoding the putative movement (MP) and nucleocapsid (NP) proteins. The two open reading frames of RNA2 are in opposite orientations and are separated by a long AU-rich intergenic region (IR) that may assume a hairpin conformation. RNA1 and RNA2 of both viruses share almost identical 5’ and 3’ termini, which are complementary to each other up to 20 nt. This genome organization is typical of members of the genus Coguvirus, with which WCLaV-1 and WCLaV-2 also share similar terminal 5’ and 3’ sequences of RNA1 and RNA2. These molecular features, together with phylogenetic reconstructions support the classification of WCLaV-1 and WCLaV2 as members of two new species in the genus Coguvirus.

西瓜皱叶相关病毒 1 和西瓜皱叶相关病毒 2（WCLaV-1 和 WCLaV-2）是布尼亚病毒目的两个未分类成员，在系统发育上与Coguvirus属（Phenuiviridae）。据报道，这两种病毒的基因组之前都由三个 RNA 片段组成。然而，两个基因组 RNA 片段的末端序列，即那些编码假定的运动蛋白 (MP) 和核衣壳 (NP) 蛋白的片段，仍未确定。总 RNA 和小 RNA 制剂的高通量测序，结合逆转录 PCR 扩增和测序，揭示 WCLaV-1 和 WCLaV-2 具有由负义 RNA1 组成的二分基因组，编码依赖于 RNA 的 RNA聚合酶和双义 RNA2，编码假定的运动 (MP) 和核衣壳 (NP) 蛋白。RNA2 的两个开放阅读框方向相反，并被一个长的富含 AU 的基因间区域 (IR) 隔开，该区域可能呈现发夹构象。两种病毒的 RNA1 和 RNA2 共享几乎相同的 5' 和 3' 末端，彼此互补达 20 nt。这种基因组组织是该属成员的典型特征Coguvirus，WCLaV-1 和 WCLaV-2 也与 Coguvirus 共享相似的 RNA1 和 RNA2 末端 5' 和 3' 序列。这些分子特征以及系统发育重建支持将 WCLaV-1 和 WCLaV2 分类为 Coguvirus 属中两个新物种的成员。