Anatomy and evolution of telomeric and subtelomeric regions in the human protozoan parasite Trypanosoma cruzi.

摘要: The subtelomeres of many protozoa are highly enriched in genes with roles niche adaptation. T. cruzi trypomastigotes express surface proteins from Trans-Sialidase (TS) and Dispersed Gene Family-1 (DGF-1) superfamilies which implicated host cell invasion. Single populations may different antigenic forms TSs. Analysis TS located at the telomeres suggests that chromosome ends could have been sites where new variants were generated. aim this study is to characterize telomeric subtelomeric regions available TriTrypDB connect sequences working draft sequence. We first identified contigs carrying repeat (TTAGGG). Of 49 identified, 45 repeats one end, whereas four internally. All display a conserved junction sequence adjacent hexamer represents signature ends. found 40 on chromosome-sized scaffolds. In addition, we able map several chromosomal bands separated by pulsed-field gel electrophoresis. structure varies widely, mainly as result large differences relative abundance organization encoding (TS DGF-1), retrotransposon hot spot (RHS), elements, RNA-helicase N-acetyltransferase genes. While pseudogenes, they also contain complete gene matching both known unknown expressed genes, indicating these do not consist nonfunctional DNA but instead functional parts genome. size 5 182 kb; smaller generated recent breakage telomere healing event. lack synteny subject recombination, increases their variability, even among homologous chromosomes. presence typical can increase chance recombination mechanisms or microhomology- mediated end joining, use for pairing free