Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành y học dành cho các bạn tham khảo đề tài: Large-scale polymorphism of heterochromatic repeats in the DNA of Arabidopsis thaliana | BMC Plant Biology BioMed Central Research article Open Access Large-scale polymorphism of heterochromatic repeats in the DNA of Arabidopsis thaliana Jerry Davison1 Anand Tyagi2 and Luca Comai 3 Address University of Washington Department of Biology Box 355325 Seattle WA 98195-5325 USA 2University of the South Pacific School of Pure and Applied Sciences Department of Biology PO Box 1168 Suva Fiji and 3University of California at Davis Section of Plant Biology and the UC Davis Genome Center 451 E. Health Sciences Drive Davis CA 95616 USA Email Jerry Davison - ox@ Anand Tyagi - tyagi_ap@ Luca Comai - lcomai@ Corresponding author Published 16 August 2007 Received 17 February 2007 BMC Plant Biology 2007 7 44 doi l47l-2229-7-44 Accepted 16 August 2007 This article is available from http l47l-2229 7 44 2007 Davison 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 The composition of the individual eukaryote s genome and its variation within a species remain poorly defined. Even for a sequenced genome such as that of the model plant Arabidopsis thaliana accession Col-0 the large arrays of heterochromatic repeats are incompletely sequenced with gaps of uncertain size persisting in them. Results Using geographically separate populations of A. thaliana we assayed variation in the heterochromatic repeat arrays using two independent methods and identified significant polymorphism among them with variation by as much as a factor of two in the centromeric l80 bp repeat in the 45S rDNA arrays and in the Athila retroelements. In the accession with highest genome size as measured by flow cytometry Loh-0 we found more than a two-fold increase in 5S RNA .
