title: Comparative genomic analysis of dinucleotide repeats in Tritryps.
abstract: The protozoans Trypanosoma cruzi, Trypanosoma brucei and Leishmania major (Tritryps), are evolutionarily ancient eukaryotes which cause worldwide human parasitosis. They present unique biological features. Indeed, canonical DNA/RNA cis-acting elements remain mostly elusive. Repetitive sequences, originally considered as selfish DNA, have been lately recognized as potentially important functional sequence elements in cell biology. In particular, the dinucleotide patterns have been related to genome compartmentalization, gene evolution and gene expression regulation. Thus, we perform a comparative analysis of the occurrence, length and location of dinucleotide repeats (DRs) in the Tritryp genomes and their putative associations with known biological processes. We observe that most types of DRs are more abundant than would be expected by chance. Complementary DRs usually display asymmetrical strand distribution, favoring TT and GT repeats in the coding strands. In addition, we find that GT repeats are among the longest DRs in the three genomes. We also show that specific DRs are non-uniformly distributed along the polycistronic unit, decreasing toward its boundaries. Distinctive non-uniform density patterns were also found in the intergenic regions, with predominance at the vicinity of the ORFs. These findings further support that DRs may control genome structure and gene expression.
authors.affiliation: Laboratorio de Interacciones Moleculares, Facultad de Ciencias, 11400 Montevideo, Uruguay.
authors.forename: María Ana
authors.initials: MA
authors.lastname: Duhagon
authors.forename: Pablo
authors.initials: P
authors.lastname: Smircich
authors.forename: Diego
authors.initials: D
authors.lastname: Forteza
authors.forename: Hugo
authors.initials: H
authors.lastname: Naya
authors.forename: Noreen
authors.initials: N
authors.lastname: Williams
authors.forename: Beatriz
authors.initials: B
authors.lastname: Garat
mesh_terms: D000818:Animals; D001483:Base Sequence; D016054:DNA, Protozoan / Q000235:genetics; D018900:Dinucleotide Repeats / Q000235:genetics*; D018503:Genome, Protozoan / Q000235:genetics*; D006801:Humans; D018320:Leishmania major / Q000235:genetics*; D011528:Protozoan Infections / Q000469:parasitology; D013045:Species Specificity; D014346:Trypanosoma brucei brucei / Q000235:genetics*; D014349:Trypanosoma cruzi / Q000235:genetics*
chemical_list: D016054:DNA, Protozoan