The Analysis Of Full Gene Sequences Of Norovirus And Astrovirus In Fecal Of Rhesus Monkeys Of Guangxi

Objective:To realize the infection status of norovirus and astrovirus of the fecal samples of rhesus monkeys in Longhu Mountain of Guangxi Zhuang Autonomous Region.To analyze the complete gene sequence,discuss the genetic evolution and their phylogenetic relation with human beings.Methods:Reverse transcription-polymerase chain reaction was used to screen norovirus and astrovirus.Each of the positive specimens was selected for gene amplification,cloning,sequencing and splicing,then the full length of the genome was obtained.The multiple sequence alignment and phylogenetic analysis of were constructed by software MEGA 6.0.Results:1.Two out of 400 fecal samples were positive of norovirus and one out of 400 fecal samples was positive of astrovirus.2.The full-length genome of norovirus was 7565bp(containing a PloyA tail),which was composed of three open reading frames(ORFs):ORF1(10-5112 nt),ORF2(5093-6715 nt)and ORF3(6715-7494 nt).Analysis of the complete sequence showed that it shared the highest homology with the strain of human G?.17 norovirus CUHK-NS-613(accession number:KU561248)(99.5%identity in nt).ORF1 and ORF3 also shared the highest homology with the strain CUHK-NS-613(99.5%and 99.4%in nucleotide(nt),99.5%and 99.2%in amino acid(aa),respectively);ORF2 sequence analysis showed that it displayed the highest identity(99.4%in nt and 99.8%in aa)to the strain CUHK-NS-491(accession number:KP698928),only one aa mutation aa245P?S(P1.1 region)was observed in the VP1 protein.Furthermore,the phylogenetic analysis showed that it was more related to CUHK-NS-613 and CUHK-NS-491 than the strain KM1509(accession number:KX356908)of GII.17 norovirus identified in rhesus monkeys.3.The full-length genome of astrovirus was 7377bp,which was composed of three open reading frames(ORFs):ORFla(120-3185 nt),ORF1b(3176-4705 nt),ORF2(4729-7239 nt).Sequence analysis of ORF1a showed that it shared the highly homology with the strain of Duck astrovirus(accession number:JX624774)(29%identity in aa).ORFlb sequence analysis showed that it displayed the highly identity(49%in aa)to the strain of Duck astrovirus(accession number:FJ919227),and ORF2 shared the highly homology with the strain of Feral pigeon astrovirus(accession number:FR727148)(37%in aa).Meanwhile,the aa phylogenetic analysis of ORFla,ORFlb and ORF2 displayed that it formed an independent cluster with the genera Avastrovirts.Furthermore,the mean genetic distance analysis of complete capsid aa showed that it shared a genetic distance of 0.759 with the representative member of the Avastrovirus species.According to the species demarcation criteria of the genera Avastrovirus by ICTV,we speculate that it may be a novel species in the genera Avastrovirus.Conclusion:The astrovirus maybe a novel species in the genera Avastrovirus,which was detected in fecal samples of rhesus monkeys in Guangxi Zhuang Autonomous Region;The G? 17 norovirus can infect not only humans but also rhesus monkeys.