The distribution, relationships and identification of enzymic variants within the subgenus Trypanozoon

Publisher Summary This chapter presents and compares the enzyme profiles of a large number of trypanosome populations from many countries. The results were obtained using thin-layer starch gel electrophoresis under similar conditions with the same range of enzymes. After electrophoresis and staining, each enzyme gave a pattern, consisting of one or several isoenzyme bands. In a trypanosome population, the combination of patterns for 11 enzymes is the “enzyme profile;” populations with the same profile belong to the same “zymodeme (Z).” The dendrogram for Trypanozoon was constructed by using Ward's method. The profile for each zymodeme is regarded as an operational taxonomic unit (OTU). Dissimilarities between all possible pairs of OTUs are calculated as Euclidean distances, which are the sums of the squared character differences. Only consistent isoenzyme bands are used. With the same raw data used for the dendrogram, the computer is used to construct a phylogenetic tree or a cladogram of developmental pathways that involved the minimal amount of genetic alteration. The dissimilarity between two zymodemes is the “patristic distance (PD)” between them through the cladogram. When constructing the initial cladogram, the characters, or bands, are weighted by using an iterative technique.