Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Minireview cung cấp cho các bạn kiến thức về ngành y đề tài: Repetitive DNA is associated with centromeric domains in Trypanosoma brucei but not Trypanosoma cruzi . | Research Open Access Repetitive DNA is associated with centromeric domains in Trypanosoma brucei but not Trypanosoma cruzi Samson O Obado Christopher Bot Daniel Nilsson Bjorn Andersson and John M Kelly Addresses Department of Infectious and Tropical Diseases London School of Hygiene and T ropical Medicine Keppel Street London WC1E 7HT UK. ỶCenter for Genomics and Bioinformatics Karolinska Institutet Berzelius vag S-171 77 Stockholm Sweden. Correspondence John M Kelly. Email Published 12 March 2007 Genome Biology 2007 8 R37 doi 186 gb-2007-8-3-r37 The electronic version of this article is the complete one and can be found online at http 2007 8 3 R37 Received 3 November 2006 Revised 16 January 2007 Accepted 12 March 2007 2007 Obado et al. licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License http licenses by which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. Abstract Background Trypanosomes are parasitic protozoa that diverged early from the main eukaryotic lineage. Their genomes display several unusual characteristics and despite completion of the trypanosome genome projects the location of centromeric DNA has not been identified. Results We report evidence on the location and nature of centromeric DNA in Trypanosoma cruzi and Trypanosoma brucei. In T. cruzi we used telomere-associated chromosome fragmentation and found that GC-rich transcriptional strand-switch domains composed predominantly of degenerate retrotranposons are a shared feature of regions that confer mitotic stability. Consistent with this etoposide-mediated topoisomerase-II cleavage a biochemical marker for active centromeres is concentrated at these domains. In the megabase-sized chromosomes of T. brucei topoisomerase-II activity is also focused at single loci that encompass regions .
