Dendrogram of the sequence comprising the S segment from hantavirus strains determined using the PAUP* 4.0b program on a Macintosh computer. A Neighbor-joining algorithm methods and the HKY-parameter model was used to generate a tree on the basis of nucleotide sequence differences in the 264-nt. Bootstrap values >50%, obtained from 1.000 pseudoreplicates of the analysis are shown for the branch points. The strain sequences under study in this paper are (BR) and are available on GenBank: Oligoryzomys nigripes [FJ402967], Micoureus paraguayanus 66 [FJ402968], Monodelphis ihering 72 [FJ402969], Didelphis aurita [FJ402970], O. nigripes 36 [FJ402971], Diphylla ecaudata 75 [FJ402972], Diphylla ecaudata 76 [FJ402973], O. nigripes 62 [FJ402974], Akodon montensis 63 [FJ402975], Oligoryzomys sp. 64 [FJ402976], Thaptomys nigrita [FJ402977], Juliomys sp. [FJ402978], Oryzomys sp. [FJ402979], Anoura caudifer [FJ402980], Akodon sp. 71 [FJ402981], Akodon montensis 73 [FJ402982]. Numbers inside parenthesis indicates the number of identical sequences. The following published S-segment sequences were included in the analysis (GenBank accession numbers): Puumala [AB297665], Bayou [L36929], Sin Nombre [NC005216], New York [U47135], Caño Delgadito [DQ285566], Anajatuba [DQ451829], Rio Mearim [DQ451828], Laguna Negra virus [AF005727], Rio Mamoré [U52136], HTN-007 [AF133254], Castelo dos Sonhos [AF307324], Andes [AF324902], Jabora virus [EF492471], Juquitiba [EF492472], Araucaria [AY740633], Araraquara [EF571895], Paranoa [EF576661].