RNA viromes of Dermacentor nuttalli ticks reveal a novel uukuvirus in Qīnghǎi Province, China

Virol Sin. 2024 Apr 26:S1995-820X(24)00066-X. doi: 10.1016/j.virs.2024.04.006. Online ahead of print.

Abstract

Ticks are a major parasite on the Qīnghǎi-Tibet Plateau, western China, and represent an economic burden to agriculture and animal husbandry. Despite research on tick-borne pathogens that threaten humans and animals, the viromes of dominant tick species remain unknown. In this study, we collected Dermacentor nuttalli ticks near Qīnghǎi Lake and identified 13 viruses belonging to at least six families through metagenomic sequencing. Four viruses were of high abundance in pools, including Xīnjiāng tick-associated virus 1 (XJTAV1), and three novel viruses: Qīnghǎi Lake virus 1, Qīnghǎi Lake virus 2 (QHLV1, and QHLV2, unclassified), and Qīnghǎi Lake virus 3 (QHLV3, genus Uukuvirus of family Phenuiviridae in order Bunyavirales), which lacks the M segment. The minimum infection rates of the four viruses among the tick groups were 8.2%, 49.5%, 6.2%, and 24.7%, respectively, suggesting the prevalence of these viruses in D. nuttalli ticks. A putative M segment of QHLV3 was identified from next-generation sequencing data and further characterized for its signal peptide cleavage site, N-glycosylation, and transmembrane region. Furthermore, we probed the L, M, and S segments of other viruses using the putative M segment sequence with sequencing data of other tick pools. By revealing the viromes of D. nuttalli ticks, this study enhances our understanding of tick-borne viral communities in highland regions. The putative M segment identified in a novel uukuvirus suggests that previously identified uukuviruses without M segments should have had the same genome organization as typical bunyaviruses. These results will facilitate virus discovery and our understanding of the phylogeny of tick-borne uukuviruses.

Keywords: Dermacentor nuttalli; M segment; Qīnghǎi Province; Uukuvirus; Virome.