Analysis Of Virus Community Of Laboratory Rabbits And Genetic Characteristics Of Novel Viral Genomes

Virus is a kind of non-cellular organism which is small and simple in structure,only contains one nucleic acid(DNA or RNA),must be parasitic in living cells and proliferate in a replication way.It can spreed and infect between people and other organisms.The traditional virus detection technology can only detect known viruses,it has limitations for the detection of unknown and novel viruses.In recent years,with the development of virology,viral metagenomic technology has made great contributions to the field of medicine and public health security.Viral metagenomic is a newly emerging technology to study virus diversity and analyze biological information in a specific environment,which is widely applied to human health,animal and plant virus detection.It is of great significance for systematic study of viruses,pathogen analysis and prevention and can dig novel viruses in depth.Digging potential novel and unknown viruses is an important way to prevent and treat emerging infectious diseases.Laboratory animals are artificially raised animals,which are used for scientific research,teaching,production,identification and other scientific experiments.Due to the low microorganism control of animals widely used for teaching and pre-experiment and the background of microorganism is also unclear with different susceptible pathogens,so they might be responsible for the outbreaks and epidemics of diseases.Viral diseases play an important role in laboratory animal diseases.Some viruses cause disease in animals that can lead to their death and some do not cause the death but can affect stabilities and reactivities of animals and affect the progress of experiments.Even more serious is that some viruses have extensive hosts and belong to zoonotic pathogens which can cause diseases in both humans and animals,such as highly pathogenic influenza,epidemic haemorrhagic fever,and rotaviruses.Rabbits are one of the earliest animals used for experiments and play a unique role in the field of medical research.but the viruses in laboratory rabbits are not clear.In order to analyze the virus community of laboratory rabbits and dig novel viruses,viral metagenomic method was used to construct libraries of oral,skin,blood and fecal samples of laboratory rabbits from school animal center.The major contents of the study are listed:1.Research on the laboratory rabbits oral viromeThe composition of virus community in the oral of laboratory rabbits mainly includes:Astroviridae 0.127%,Smacoviridae 0.127%,Adenoviridae 0.892%,Ascoviridae 1.401%,Circoviridae 2.675%,Herpesviridae 0.892%,Parvoviridae 30.70%,Polyomaviridae 53.757%,Poxviridae 1.528%,Unclassified ssDNA Virius 3.057%.The analysis of virus composition in the oral of laboratory rabbits presented that:(1)The species of virus was diverse.(2)Polyomaviridae accounted for 53.757%,followed by Parvoviridae,which accounted for 30.70%.(3)The oral libraries contain a variety of mammals-infecting viruses belonging to Astroviridae,Adenoviridae,Circoviridae,Herpesviridae,Parvoviridae and Polyomaviridae.2.Research on the laboratory rabbits skin viromeThe composition of virus community in the skin of laboratory rabbits mainly includes:Acoviridae 0.605%,Baculoviridae 0.242%,Circoviridae 7.376%,Retroviridae 0.605%,Parvoviridae 80.773%,Poxviridae 0.363%,Coronaviridae 0.484%,Polyomaviridae 0.121%,Herpesviridae 0.242%,Unclassified ssDNA Virius 8.101%.The analysis of virus composition in the skin of laboratory rabbits showed that:(1)The virus species was diverse.(2)Parvoviridae was the largest component,which reached 80.773%.(3)The skin libraries contain a lot of viruses belonging to Circoviridae,Retroviridae,Parvoviridae,Coronaviridae,Polyomaviridae,and Herpesviridae that can infect mammals.3.Research on the laboratory rabbits blood viromeThe composition of virus community in the blood of laboratory rabbits mainly includes:Acoviridae 0.614%,Baculoviridae 1.434%,Circoviridae 9.836%,Retroviridae 30.942%,Parvoviridae 19.262%,Poxviridae 7.786%,Astroviridae 0.205%,Flaviviridae 6.967%,Picobirnaviridae 0.819%,Coronaviridae 0.409%,Unclassified ssDNA Virius 13.114%.The analysis of virus community in the blood of laboratory rabbits showed that:(1)The species of virus was diverse.(2)Retroviridae accounted for 30.942%,followed by the family Parvoviridae 19.262%.(3)The blood libraries contain a variety of viruses belonging to Circoviridae,Retroviridae,Parvoviridae,Astroviridae,Flaviviridae,Picobirnaviridae and Coronaviridae that can infect mammals.4.Research on the laboratory rabbits fecal viromeThe composition of virus community in the feces of laboratory rabbits mainly includes:Adenoviridae 0.0696%,Baculoviridae 0.162%,Circoviridae 5.085%,Herpesviridae 0.394%,Parvoviridae 45.106%,Poxviridae 0.174%,Caliciviridae 0.337%,Coronaviridae 25.507%,Picobirnaviridae 3.796%,Picornaviridae 1.312%,Ascoviridae 0.209%,Unclassified ssDNA Virius 15.279%,Microviridae.The analysis of virus community in the feces of laboratory rabbits showed that:(1)The abundance of virus sequences was high and the species of virus was diverse.(2)Parvoviridae accounted for 45.106%,followed by Coronaviridae,accounting for 25.507%.(3)The fecal libraries contain a variety of viruses belonging to Picornaviridae,Caliciviridae,Coronaviridae,Picobirnaviridae and Circoviridae that can infect mammals.5.Discovery of a novel polyomavirus and phylogenetic analysisA novel polyomavirus named RabPyV was discovered in the oral library of laboratory rabbits(rabbitoral01),with a genome size of 5162bp,encoding five major proteins including the large T antigen(LTAg),small T antigen(STAg),VP 1,VP2 and VP3 proteins.Phylogenetic analysis based on the LTAg,VP1 and VP2 protein domains revealed that RabPyV may be involved in the recombination event.The recombinant analysis of related genomes confirmed that the novel polyomavirus is a recombinant of rodent-like and avian-like polyomavirus.Polyomaviruses have been identified in birds,cattles,rabbits,rodents,bats,and humans.They can infect most immunologically suppressed mammals,causing sarcomas or cancers in organs or multiple sites among some hosts,but they are not pathogenic to normal hosts,and can also cause long-term and persistent subclinical infections in immune competent hosts.6.Identification and phylogenetic analysis of viruses in fecal samples of laboratory rabbitsFour different viruses were analyzed in the fecal libraries of laboratory rabbits,including Picobirnavirus,Bocavirus,Coronavirus and Microvirus belonging to Picobirnaviridae,Parvoviridae,Coronaviridae and Microviridae.The phylogenetic trees were conducted according to the related amino acid sequences.Conclusion:(1)The composition of virus community in laboratory rabbits was analyzed by using viral metagenomics.(2)The composition of virus community in oral,skin,blood and feces of laboratory rabbits presents diversity,the same virus may exist in several different sites.(3)This study increased the genetic information of viruses in the laboratory rabbits,which can provide a genetic basis for the study of their occurrence,development,transmission and association with diseases.