Observation of positive selection within hypervariable regions of a newly identified DNA virus (SEN virus)(1).
To elucidate the evolution of SEN virus (SEN-V), serial sequences of chronically SEN-V-infected patients were analyzed. In the hypervariable regions, non-synonymous substitutions significantly predominated. This could be attributed to positive selection in evading immune surveillance of the hosts and to establish a persistent infection. On the basis of the sequences in the two open reading frames of SEN-V DNA, the rate of synonymous substitutions was 7.32 x 10(-4) per site per year. Since this rate is close to RNA viruses and higher than other DNA viruses, the SEN-V might be replicated by machinery with poor or no proofreading function.
Umemura
Takeji
T
Department of Transfusion Medicine, Warren Grant Magnuson Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA.
Tanaka
Yasuhito
Y
Kiyosawa
Kendo
K
Alter
Harvey J
HJ
Shih
J Wai-Kuo
JW
D002908:Chronic Disease; D018136:Circoviridae / Q000235:genetics* / Q000276:immunology; D018173:Circoviridae Infections / Q000097:blood / Q000150:complications / Q000276:immunology / Q000821:virology*; D022801:Complementarity Determining Regions / Q000235:genetics*; D004279:DNA, Viral / Q000097:blood / Q000235:genetics; D006505:Hepatitis / Q000150:complications; D006526:Hepatitis C / Q000150:complications; D006801:Humans; D007157:Immunologic Surveillance; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012044:Regression Analysis; D012641:Selection, Genetic
D022801:Complementarity Determining Regions; D004279:DNA, Viral