Figure 3. Neighbor-joining phylogram of 38 Toxoplasma gondii strains derived from polymerase chain reaction–restriction fragment length polymorphism typing at loci (SAG2, SAG3, GRA6, and BTUB). Distances were calculated according to Nei and Li (21) and the distance matrix analyzed using the phylogenetic analysis program PAUP*4.0b to generate an unrooted phylogram (22). The numbers on the branches indicate the bootstrap values (1,000 replicates). Strain designations are shown in the Table.