ABSTRACT
Objective To sequence and analyze the complete genome of two human coronavirus NL63 (HCoV-NL63) strains collected from Beijing Children Hospital .Methods Eighteen pairs of primers were designed according to the gene sequences of HCoV-NL63 reference strain ( HCoV-NL63_Amsterdam 1) and used to amplify the target fragments covering the complete genome of HCoV-NL63 strains.Rapid ampli-fication of cDNA ends ( RACE) and RT-PCR assays were used to amplify the full length genome of HCoV-NL63 strains.Phylogenetic analysis was conducted by using Mega 5.0 software.Results The complete ge-nome sequences of the two HCoV-NL63 strains were 27 538 bp in length, showing a homology of 99.1%in nucleotide sequences .There were 15 consecutive bases deleted from 1a region.The systematic phylogenetic analysis demonstrated that four genotypes of NL 63 virus including A , B, C and D have been identified , and two domestic strains were belonged to the new genotype D .Conclusion The complete genome sequences of two domestic HCoV-NL63 isolates were identified for the first time .This study provided evidence for further investigation on molecular epidemiology of HCoV-NL63 in China .