Figure 2. A: Maximum parsimony phylogenetic tree B: Distance-based phylogenetic tree. The tree was built under the Tamura-Nei model of DNA substitution with estimation of the shape parameter of the gamma distribution (28). This model and the associated parameters resulted from testing our dataset with the program MODELTEST 3.06 (26). Both trees include Argentinean and Uruguayan hantaviruses from hantavirus pulmonary syndrome (HPS) case-patients and rodents. Hantavirus sequences from HPS case-patients in Uruguay: Ac1Hu, Ca2Hu, Bu3Hu, Pe4Hu, Uru1/97, Uru1/99. Hantavirus sequences from yellow pygmy rice rats: U89, Sa63, Ce20, Ce22. Sin Nombre virus was used as outgroup.*Specimens deposited at the Specimen Collection of the Sección Zoología Vertebrados, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay, with the following numbers: U89=ZVC-M2154, SA63=ZVC-M2155, Ce20=ZVC-M2156, Ce22=ZVC-M2157, and Ce155=ZVC-M2158.