AN ISOENZYME SURVEY OF TRYPANOSOMA-CRUZI GENETIC-VARIABILITY IN SYLVATIC CYCLES FROM FRENCH-GUIANA

Twenty-seven trypanosomatidae stocks isolated from various hosts in Fr ench Guiana have been surveyed by Multilocus Enzyme Electrophoresis on cellulose acetate plates. The variability observed at 22 different en zyme systems was considerable, since 21 different enzyme profiles (zym odemes) could be distinguished. Clustering analysis and comparison wit h four laboratory reference stocks showed clearly that three stocks we re distantly related from the rest and most probably cannot be include d in the species Trypanosoma cruzi. All the other stocks were more rel ated to the formerly described zymodeme I than to the formerly describ ed zymodemes II and III. Genotype variability in this T. cruzi sylvati c population was notably higher than in domestic populations of the sa me parasite. This could suggest more frequent genetic exchange occurri ng in sylvatic cycles. Nevertheless, a population genetic analysis of the data showed a considerable linkage disequilibrium, which rather fa vors the hypothesis that T. cruzi has a basically clonal population st ructure in this ecosystem too. (C) 1995 Academic Press, Inc.