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Phylogenetic tree of measles wild-type virus strains of China in 2006-2007 and WHO reference MeV strains (black dots) based on the 456 nucleotide sequences coding for the COOH-terminus of the nucleoprotein. The dendrogram was created with MEGA4 software and the neighbor-joining method (500 bootstraps). Genetic distances are represented as numbers of nucleotide differences between strains.
