Showing papers on "Dendrogram published in 1990"

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

Abstract: 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.

Electrophoretic Comparison of Enzymes as a Chemotaxonomic Aid among Aspergillus Taxa: (1) Aspergillus Sects. Ornati and Cremei

Abstract: Polyacrylamide slab gel electrophoresis with specific staining for five enzymes was used as a chemotaxonomic criterion for comparing 35 isolates assigned to 12 species in Aspergillus subgen. Ornati sect. Ornati and three species in subgen. Circumiati sect. Cremet. These were glucose-6-phosphate dehydrogenase, malate dehydrogenase, fumarase, alcohol dehydrogenase, and glutamate dehydrogenase. A numerical analysis was performed on the basis of the similarity values in patterns of five enzymes. The results are presented as a dendrogram. Isolates from different geographical and ecological habitats within the same species were identical or very similar in the enzyme patterns. In the dendrogram, isolates were divided into five major clusters. Isolates within the same species were linked to each other with a high similarity value of 73% or more, whereas each species was linked to one another with a similarity value of 15 to 70%. The three clusters were a heterogeneous assemblage in teleomorphs or ubiquinone systems, or both. Comparisons of enzyme patterns are considered to be useful tools at the species level in the classification of these Aspergillus taxa.