YN87448 virus strain was isolated from a fevered female patient (52 years old ) in Yunnan Province in 1986, and was identified as a member of Alphavirus using serological method. One primer was designed from common hairpin conserved region of Alphavirus. Two fragments were amplified by single primer differential RT PCR, and they were cloned into pGEM T vector. Sequences were determined, and then analyzed by Software and GenBank. Results showed that the 1118pb long fragment was highly homologous to the sequence of Sindbis like virus S.A.A.R86. The homogeneity of the 1118bp fragment between YN87448 virus strain and S.A.A.R86 virus strain was 98%. Single primer differential RT PCR is a useful method with simple, economic, and practical value for Alphavirus identification.
XJ 160 virus was isolated in 1990 from Xinjiang, China. The biological characteristics of XJ 160 virus suggested that it might be a Togavirus. The serological tests showed that XJ 160 virus is a Sindbis like virus. The complete 11626 base nucleotide sequence of XJ 160 has been determined recently. It is necessary to establish a reverse genetic system for rescue of XJ 160 virus from its cDNA clone. We describe here the constructon of full length cDNA clone of XJ 160 virus. The total RNA were extracted from BHK cells infected with XJ 160 virus. Specific primers were used to amplify five fragments covering the whole genome of XJ 160 virus. All of these five fragments have the restriction enzyme sites at both termini to be assembled into the full length cDNA clone. The five PCR fragments were cloned into pGEM T vector. The clones with SP6 inserted direction were selected for subsequent manipulation. After a series of plasmid manipulation, the full length cDNA clone of XJ 160 virus was assembled into pBluescript vector. The restriction enzyme assay and sequencing analysis demonstrated that the whole genome of XJ 160 virus was correctly assembled into pBluescript vector, with added SP6 promoter in 5′ terminus and poly A in its 3′ terminus.
