Sequences of the internal transcribed spacers (ITS) of the nuclear ribosomal DNA are important molecular markers in phylogenetic analyses. To obtain sequences from herbarium material in which DNA often is severely degraded, the ITS region has to be amplified in two steps. Two methods that reduce bench time and reagents used are described. (i) Separately amplified preparations of subunits ITS-1 ...

American trypanosomiasis is a common zoonosis in Colombia and Trypanosoma cruzi presents a wide distribution throughout the country. Although some studies based on enzyme electrophoresis profiles have described the population structure of the parasite, very few molecular analyses of genotipic markers have been conducted using Colombian strains. In this study, we amplified the non-transcribed sp...

The ribosomal DNA (rDNA) cluster of insects contains several hundred repeating structural-functional units and, therefore, is a typical example of a multigene family. Eukaryotic ribosomal RNA (rRNA) genes (18S, 5.8S, and 28S like) are arranged in tandemly repeated clusters in the nucleolus organizers, separated by several spacers, namely the nontranscribed spacer, the external transcribed space...