Fig 4. Evolutionary relationships among assemblages of G. duodenalis at the BG locus inferred by a Neighbor-Joining analysis of the nucleotide sequence covering a 487-bp region (positions 108 to 573 of GenBank accession number AY072727) of the gene.

The percentage of replicate trees in which the associated taxa clustered together in the bootstrap test (500 iterations) is indicated next to the branches. Bootstrap values lower than 50% were not displayed. The evolutionary distances were computed using the Kimura 2-parameter method. The rate variation among sites was modelled with a gamma distribution (shape parameter = 2). Filled circles represent B sequences from this study, whereas open circles indicate B sequences previously reported in human isolates from Ethiopia (see ref. [22]).No outgroup taxa was used as beta-giardin is a Giardia-specific structural protein.