Figure 2. Phylogenetic tree of hantaviruses from rodents in Inner Mongolia, China, 2003–2006. The tree is based on partial sequences of the small (S) segment (nt 620–999 for Seoul virus [SEOV] and nt 614–993 for Hantaan virus [HTNV]). PHYLIP program package (3.65) (http://evolution.genetics.washington.edu/phylip.html) was used to construct the phylogenetic trees by using the neighbor-joining (NJ) and the maximum likelihood (ML) methods with 1,000 bootstrap replicates. The tree constructed by using the ML method had a similar topology as that constructed by using the NJ method (data not shown). Bootstrap values were calculated from 1,000 replicates; only the values >50% are shown at the branch nodes. The sequence of Sin Nombre virus (SNV) was used as the outgroup. Partial S segment sequences recovered from A. agrarius field mice trapped in the Hulunbeier District were designated as HulunbeierAa58, HulunbeierAa78, HulunbeierAa90, and HulunbeierAa118; partial S segment sequences from R. norvegicus rats trapped in the Huhehaote District were designated as HuhehaoteRn-; and those from R. norvegicus rats trapped in the Bayannaoer District were designated as BayannaoerRn14, BayannaoerRn42, BayannaoerRn86, BayannaoerRn98, and BayannaoerRn116. Sequences obtained in this study are shown in boldface. All nucleotide sequence data reported here are available in GenBank (accession nos. FJ514504–FJ514546). The GenBank accession nos. of the other partial S segment sequences are SNV/NM H10 (L25748), HTNV/76-118 (M14626), HTNV/CFC94-2 (X95077), HTNV/CJAp93 (EF208953), HTNV/Bao14 (AB127998), HTNV/A9 (AF329390), HTNV/Hu (AB027111), HTNV/Z10 (AF18498), HTNV/Q32 (AB027097), HTNV/SN7 (AF288657), HTNV/84Fli (AY017064); SEOV/NY039 (EF210131), SEOV/Gou3 (AF288651), SEOV/QH367 (DQ081717), SEOV/SR11 (M34881), SEOV/Tchoupitoulas (AF329389), SEOV/IR461(AF329388), SEOV/BJFT01 (DQ519033), SEOV/L99 (AF488708), SEOV/R22 (AF488707), SEOV/Bjhd01 (AY627049), SEOV/K24-V2 (AF288655), SEOV/Z37 (F187082), SEOV/ZT10 (AY766368), and SEOV/Hb8610 (AF288643). Scale bar indicates genetic distance.