Extrachromosomal circles of satellite repeats and 5S ribosomal DNA in human cells

Bibliographic Details
Title: Extrachromosomal circles of satellite repeats and 5S ribosomal DNA in human cells
Authors: Cohen Sarit, Agmon Neta, Sobol Olga, Segal Daniel
Source: Mobile DNA, Vol 1, Iss 1, p 11 (2010)
Publisher Information: BMC, 2010.
Publication Year: 2010
Collection: LCC:Genetics
Subject Terms: Genetics, QH426-470
More Details: Abstract Background Extrachomosomal circular DNA (eccDNA) is ubiquitous in eukaryotic organisms and was detected in every organism tested, including in humans. A two-dimensional gel electrophoresis facilitates the detection of eccDNA in preparations of genomic DNA. Using this technique we have previously demonstrated that most of eccDNA consists of exact multiples of chromosomal tandemly repeated DNA, including both coding genes and satellite DNA. Results Here we report the occurrence of eccDNA in every tested human cell line. It has heterogeneous mass ranging from less than 2 kb to over 20 kb. We describe eccDNA homologous to human alpha satellite and the SstI mega satellite. Moreover, we show, for the first time, circular multimers of the human 5S ribosomal DNA (rDNA), similar to previous findings in Drosophila and plants. We further demonstrate structures that correspond to intermediates of rolling circle replication, which emerge from the circular multimers of 5S rDNA and SstI satellite. Conclusions These findings, and previous reports, support the general notion that every chromosomal tandem repeat is prone to generate eccDNA in eukryoric organisms including humans. They suggest the possible involvement of eccDNA in the length variability observed in arrays of tandem repeats. The implications of eccDNA on genome biology may include mechanisms of centromere evolution, concerted evolution and homogenization of tandem repeats and genomic plasticity.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 1759-8753
Relation: http://www.mobilednajournal.com/content/1/1/11; https://doaj.org/toc/1759-8753
DOI: 10.1186/1759-8753-1-11
Access URL: https://doaj.org/article/8132085608a9441ebb4b79ed73bb1ec6
Accession Number: edsdoj.8132085608a9441ebb4b79ed73bb1ec6
Database: Directory of Open Access Journals
More Details
ISSN:17598753
DOI:10.1186/1759-8753-1-11
Published in:Mobile DNA
Language:English