Affiliation:
1. State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products, Key Laboratory of Biotechnology in Plant Protection of Ministry of Agriculture and Zhejiang Province, Institute of Plant Virology, Ningbo University, Ningbo, China
Abstract
ABSTRACT
Negevirus is a recently proposed taxon of arthropod-infecting virus, which is associated with plant viruses of two families (
Virgaviridae
and
Kitaviridae
). Nevertheless, the evolutionary history of negevirus–host and its relationship with plant viruses remain poorly understood. Endogenous nege-like viral elements (ENVEs) are ancient nege-like viral sequences integrated into the arthropod genomes, which can serve as the molecular fossil records of previous viral infection. In this study, 292 ENVEs were identified in 150 published arthropod genomes, revealing the evolutionary history of nege-like viruses and two related plant virus families. We discovered three novel and eight strains of nege-like viruses in 11 aphid species. Further analysis indicated that 10 ENVEs were detected in six aphid genomes, and they were divided into four types (ENVE1-ENVE4). Orthologous integration and phylogenetic analyses revealed that nege-like viruses had a history of infection of over 60 My and coexisted with aphid ancestors throughout the Cenozoic Era. Moreover, two nege-like viral proteins (CP and SP24) were highly homologous to those of plant viruses in the families
Virgaviridae
and
Kitaviridae
. CP- and SP24-derived ENVEs were widely integrated into numerous arthropod genomes. These results demonstrate that nege-like viruses have a long-term coexistence with arthropod hosts and plant viruses of the two families,
Virgaviridae
and
Kitaviridae
, which may have evolved from the nege-like virus ancestor through horizontal virus transfer events. These findings broaden our perspective on the history of viral infection in arthropods and the origins of plant viruses.
IMPORTANCE
Although negevirus is phylogenetically related to plant virus, the evolutionary history of negevirus–host and its relationship with plant virus remain largely unknown. In this study, we used endogenous nege-like viral elements (ENVEs) as the molecular fossil records to investigate the history of nege-like viral infection in arthropod hosts and the evolution of two related plant virus families (
Virgaviridae
and
Kitaviridae
). Our results showed the infection of nege-like viruses for over 60 My during the arthropod evolution. ENVEs highly homologous to viral sequences in
Virgaviridae
and
Kitaviridae
were present in a wide range of arthropod genomes but were absent in plant genomes, indicating that plant viruses in these two families possibly evolved from the nege-like virus ancestor through cross-species horizontal virus transmission. Our findings provide a new perspective on the virus–host coevolution and the origins of plant viruses.
Funder
MOST | National Key Research and Development Program of China
MOST | National Natural Science Foundation of China
Publisher
American Society for Microbiology