Study On Diversity Of Horse-origin Papillomavirus

Objective: In our pioneer study with Chinese horses,we found HPV-18 and EcPV-1.To elucidate the species and genetic characteristics of papillomaviruses carried by horses,this study performed the diversity of horse-origin papillomaviruses via virome,and laid the foundation for the epidemiology of equine papillomavirus in China.Methods:(1)The c DNA library of the nasal swab samples were prepared.Briefly,samples were pooled to extract the viral nucleic acids that were reverse transcribed and then randomly amplified.(2)To obtain the diversity of horse-origin papillomavirus,all samples were screened using the specific PCR targeting Mammalian papillomavirus contigs of virome.(3)To promote understanding of the prevalence of horse-origin papillomaviruses,samples from Changji,Urumqi and Yili were detected.(4)sequences analysis revealed genetic characteristics of horse-origin papillomaviruses.Results:(1)The metagenomics analysis generated 68 077 096 reads,of which 2 756 054(4.0%)could be annotated to seven known mammalian virus families,includes the Papillomaviridae,Retroviridae,Herpesviridae,Astroviridae,Circoviridae,Paramyxoviridae and Parvoviridae.(2)PCR results showed that the positive rates of horses-origin HPV-115,HPV-124,EcPV-1,EcPV-2 and EcPV-7 were 0.6%(2/325),1.2%(4/325),2.9%(7/242),2.5%(6/242),1.2%(3/242),respectively.(3)The complete genome of HPV-115 identified in this study shared 99.6% high nt identity with HPV-115 GC02 from Argentina.Phylogenetic analysis showed that HPV-115 identified in this study most closly relationship to HPV-115 GC02.E6 gene of HPV-124 identified in this study and HPV-124 NJ3900 from USA had 99.5% high nt identity.Seven EcPV-1 L1 gene were obtained,and shared 99.8% nt identity with Japanese EcPV-1 150904.First detection of EcPV-2 and-7 in semen suggested that the primary route for transmission of these two viruses could be through sexual activities in horses.The complete genomes analysis of EcPV-2 and EcPV-7 showed that the viruses might have entered Xinjiang through horse trade.Conclusion:(1)This was the first study on identify HPV-115 and HPV-124 in horses,and in animal.(2)First detection of EcPV-2 and-7 in Chinese horses.(3)EcPV-2and-7 might transmit using sexual activities.(4)HPV-115?EcPV-1?EcPV-2 and EcPV-7 identified in this study were new variants of HPV-115?EcPV-1?EcPV-2 and EcPV-7.