title: Spliced leader RNA gene promoter sequence heterogeneity in CL-Brener Trypanosoma cruzi reference strain.
abstract: Trypanosoma cruzi is divided into two phylogenetic lineages, T. cruzi I and T. cruzi II, which contain different spliced leader (SL) RNA gene promoter sequences: Class I SL gene promoter sequences are found in T. cruzi II, and Class II sequences in T. cruzi I. We analysed different SL RNA promoter sequences from CL-Brener reference strain, belonging to T. cruzi II lineage, and detected sequences that differed within the -80/+1 highly conserved region. Indeed, many of these divergent SL promoters present features of T. cruzi I promoters. Some of these sequences were grouped into the T. cruzi I sequences clade by Bayesian analysis. The results presented herein show that sequence heterogeneity in SL RNA gene promoter not only exists between T. cruzi strains but also within CL-Brener strain. These CL-Brener "T. cruzi I-like" sequences could be considered a molecular trace of a hybrid origin of the SL RNA gene and a new evidence for the presence of sequences of T. cruzi I origin into a T. cruzi II strain. The possible origins of these sequences are discussed.
authors.affiliation: IBR, Facultad de Ciencias Bioquímicas y Farmacéuticas, UNR, Suipacha 531, CP2000, Rosario, Argentina.
authors.forename: Pamela
authors.initials: P
authors.lastname: Cribb
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Tapia
authors.forename: Patricio
authors.initials: P
authors.lastname: Diosque
authors.forename: Esteban
authors.initials: E
authors.lastname: Serra
mesh_terms: D000818:Animals; D001483:Base Sequence; D001499:Bayes Theorem; D017125:Genes, Protozoan; D008969:Molecular Sequence Data; D010802:Phylogeny; D011401:Promoter Regions, Genetic; D016053:RNA, Protozoan / Q000235:genetics*; D020038:RNA, Spliced Leader; D012689:Sequence Homology, Nucleic Acid; D014349:Trypanosoma cruzi / Q000145:classification / Q000235:genetics*
chemical_list: D016053:RNA, Protozoan; D020038:RNA, Spliced Leader