Origin and evolution of emerging Liao ning Virus (genus Seadornavirus, family Reoviridae)

Abstract

Background: Liao ning virus (LNV) is a member of the genus Seadornavirus, family Reoviridae and has been isolated from kinds of vectors in Asia and Australia. However, there are no systematic studies describe the molecular genetic evolution and migration of LNVs. With the development of bioinformatics, viral genetic data combining the information of virus isolation time and locations could be integrated to infer the virus evolution and spread in nature. Methods: Here, a phylogenetic and phylogeographic analysis using Bayesian Markov chain Monte Carlo simulations was conducted on the LNVs isolated from a variety of vectors during 1990-2014 to identify the evolution and migration patterns of LNVs. Results: The results demonstrated that the LNV could be divided into 3 genotypes, of which genotype 1 mainly composed of LNVs isolated from Australia during 1990 to 2014 and the original LNV strain (LNV-NE97-31) isolated from Liaoning province in northern China in 1997, genotype 2 comprised of the isolates all from Xinjiang province in western China and genotype 3 consisted the isolates from Qinghai and Shanxi province of central China. LNVs emerged about 272 years ago and gradually evolved into three lineages in the order genotype 1, genotype 2 and genotype 3. Following phylogeographic analysis, it shows genotype 1 LNVs transmitted from Australia (113°E-153°E, 10°S-42°S) to Liaoning province (118°E-125°E,38°N-43°N) in Northeast Asian continent then further spread across the central part of China to western China (75°E-95°E,35°N-50°N).

Molecular signature of domestication in the arboviral vectorAedes aegypti

“…A total of 5 new nrEVEs (Guato_2, CFAV_EVE-4, CFAV_EVE_1, CFAV-EVE-5, Aedes aegypti toti_like-7) are unique of out-of-Africa mosquitoes and, overall, new nrEVEs have a higher nucleotide identity to cognate viruses than reference nrEVEs. With the exception of three integrations from the Liao Ning virus belonging to the Seadornavirus genus (Reoviridae family), which includes emerging pathogens (50), all new nrEVEs are from limited number of ISVs. We also observed frequent rearrangement events following integration, especially for nrEVEs with similarity to flaviviruses that map in piRNA clusters, supporting the conclusion that nrEVEs contribute to the genetic flexibility of Ae.…”