FIG. 2.

Markov chain Monte Carlo (MCMC) tree of 35 CRF07_BC Gag sequences constructed by Bayes 3.1. Significant linkages in Bayesian phylogenetic inference analysis were considered as those having posterior probabilities >90%. Three big clusters were identified and labeled on the right side and they correspond to “Recent gag” sequences, “Earlier gag” sequences, and “earliest gag” sequences. Four regional subclusters are formed by strains from corresponding regions, including Yunnan, Liaoning, Sichuan, and Xinjiang, and are labeled on the right side, neighbored to cluster labels. Note that several regional subclusters are joined by other regional strains.