K. Lewicka et al., AN ISOENZYME SURVEY OF TRYPANOSOMA-CRUZI GENETIC-VARIABILITY IN SYLVATIC CYCLES FROM FRENCH-GUIANA, Experimental parasitology, 81(1), 1995, pp. 20-28
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.