Trypanosoma brucei and Trypanosoma cruzi cause different human disease
s. As strategies for immune evasion, T. brucei undergoes antigenic var
iation whereas T. cruzi becomes an intracellular organism. This fundam
ental difference is reflected by major differences in their genome org
anizations. Recent comparisons of their gene sequences indicate that t
hese two trypanosome species are highly divergent evolutionarily.