Preliminary Study Of The Tick Virome Sampled From Different Hosts

During the blood-meal,the obligate blood-feeding parasite,ticks transmit large number of arthropod-borne viruses to the bitten hosts,which poses a huge threat to the health of humans and livestock.Therefore,surveillance of tick-borne viruses is an indispensable tool for understanding viral spatial-temporal dynamics,as well as exploring the mechanisms of interactions between tick-borne virus-ticks-hosts,and predicting tick-borne diseases that may erupt.Using viral metagenomics,this study conducted a preliminary study of tick virome:1.This research studied the morphological identification and molecular identification of colleted samples:(1)Results showed that there were four species of ticks: H.longicornis,H.flava,R.sanguineus,R.turanicus.(2)There were clear differences in the evolutionary relationship between COI genes among four tick species.2.Tick-borne virus libraries were constructed to study the composition of viral community:(1)Tick virome was mainly composed by: Unclassified virus 89.8% and Classified virus 10.2%.(2)The classified virus was mainly composed by Circoviridae 24.5%,Virgaviridae 23.1%,Phenuiviridae 22.5%,Baculoviridae 7.2%,and Rhabdoviridae 5.3%.3.The study also analyzed the metagenomics of tick-borne viruses according to sampled hosts:(1)10 viral families were detected positively in all three hosts.They were Phenuiviridae,Retroviridae,Baculoviridae,Rhabdoviridae,Iridoviridae,Poxviridae,Virgaviridae,Phycodnaviridae,Herpesviridae and Microviridae.(2)Ticks with different source of hosts pose different dominant viruses.Dominant viruses in tick virome from goat were Phenuiviridae and Nairoviridae;Poxviridae was dominant in tick virome from cattle;Circoviridae,Virgaviridae and Phenuiviridae were dominant in tick virome from canines.(3)The Circoviridae was only positive in canines' tick.4.The whole genomes which was 2063 bp in length of Canine circovirus was identified in the tick sampleed from police dog in Nanchang,Jiangxi.The viral genome contained two main open reading frames(ORFs),Rep and Cap.There were some representative stem-loop structures between the coding regions of Rep and Cap.The construction of phylogenetic tree showed that the virus y was clustered with the strains isolated from Thailand(MG737378.1)and China(MF797786.1).