title: Genomic organization and transcription analysis of the 195-bp satellite DNA in Trypanosoma cruzi.
abstract: The 195-bp satellite DNA is the most abundant Trypanosoma cruzi repetitive sequence. Here we show by RNA blotting and RT-PCR that 195 SAT is intensely transcribed. We observed a positive correlation between the level of satellite RNA and the abundance of the satellite copies in the genome of T. cruzi strains and that the satellite expression is not developmentally regulated. By analyzing CL Brener individual reads, we estimated that 195 SAT corresponds to approximately 5% of the CL Brener genome. 195 SAT elements were found in only 37 annotated contigs, indicating that a large number of satellite copies were not incorporated into the assembled data. The assembled satellite units are distributed in non-syntenic regions with Trypanosoma brucei and Leishmania major genomes, enriched with surface proteins, retroelements, RHS and hypothetical proteins. Satellite repeats were not observed in annotated subtelomeric regions. We report that 12 satellite sequences are truncated by the retroelement VIPER.
authors.affiliation: Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Avenida Professor Lineu Prestes 748, CEP 05508-000 São Paulo, Brazil.
authors.forename: Camila
authors.initials: C
authors.lastname: Martins
authors.forename: Cassio Silva
authors.initials: CS
authors.lastname: Baptista
authors.forename: Susan
authors.initials: S
authors.lastname: Ienne
authors.forename: Gustavo C
authors.initials: GC
authors.lastname: Cerqueira
authors.forename: Daniella C
authors.initials: DC
authors.lastname: Bartholomeu
authors.forename: Bianca
authors.initials: B
authors.lastname: Zingales
mesh_terms: D000818:Animals; D016054:DNA, Protozoan / Q000032:analysis*; D004276:DNA, Satellite / Q000032:analysis*; D030561:Databases, Nucleic Acid; D005786:Gene Expression Regulation; D018503:Genome, Protozoan; D016053:RNA, Protozoan / Q000032:analysis; D012091:Repetitive Sequences, Nucleic Acid; D018626:Retroelements; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014158:Transcription, Genetic; D014349:Trypanosoma cruzi / Q000235:genetics*
chemical_list: D016054:DNA, Protozoan; D004276:DNA, Satellite; D016053:RNA, Protozoan; D018626:Retroelements