Trypanosoma cruzi: Sequence analysis of the variable region of kinetoplast minicircles

• DOI: 10.1016/j.exppara.2006.04.005
• Publication Date: 2006-06-01T19:41:59Z
• Authors: Jenny Telleria; Bénédicte Lafay; Myrna Virreira; Christian Barnabé; Michel Tibayrenc; Michal Svoboda
• Keywords: 0301 basic medicine; hypervariable domain; Evolution; kinetoplast DNA kDNA polymorphism; Trypanosoma cruzi; Editing; Polymerase Chain Reaction; 03 medical and health sciences; Sequence Homology, Nucleic Acid; evolution; Animals; Cluster Analysis; Humans; DTU Discrete Typing Units; Cloning, Molecular; Repetitive Sequences, Nucleic Acid; minicircles; DTU (Discrete Typing Units); Polymorphism, Genetic; Kinetoplast DNA (kDNA) polymorphism; editing; DNA, Kinetoplast; Hypervariable domain; Sequence Analysis, DNA; Sciences bio-médicales et agricoles; Minicircles

The comparisons of 170 sequences of kinetoplast DNA minicircle hypervariable region obtained from 19 stocks of Trypanosoma cruzi and 2 stocks of Trypanosoma cruzi marenkellei showed that only 56% exhibited a significant homology one with other sequences. These sequences could be grouped into homology classes showing no significant sequence similarity with any other homology group. The 44% remaining sequences thus corresponded to unique sequences in our data set. In the DTU I ("Discrete Typing Units") 51% of the sequences were unique. In contrast, in the DTU IId, 87.5% of sequences were distributed into three classes. The results obtained for T. cruzi marinkellei, showed that all sequences were unique, without any similarity between them and T. cruzi sequences. Analysis of palindromes in all sequence sets show high frequency of the EcoRI site. Analysis of repetitive sequences suggested a common ancestral origin of the kDNA. The editing mechanism that occurs in kinetoplastidae is discussed.