Figure 4. Unweighted maximum parsimony tree produced by PAUP 3.1 software comparing a 397 nt portion of the hantavirus S genomic segments (residues 207 to 603) of patients and rodents infected with Bayou virus. A selection of other prototypical hantavirus sequences, each of which was compared antigenically in Figure 2, was included for comparison. Other hantaviruses are abbreviated as follows: RM=Rio Mamoré; MULE=Muleshoe; SN= Sin Nombre; PUU=Puumala; and SEO=Seoul. Human-derived Bayou virus sequences are indicated by Case, and rodent sequences by OP (Oryzomys palustris) or SH (Sigmodon hispidus). TX=Texas, LA=Louisiana.