Extrachromosomal microDNAs and chromosomal microdeletions in normal tissues.
We have identified tens of thousands of short extrachromosomal circular DNAs (microDNA) in mouse tissues as well as mouse and human cell lines. These microDNAs are 200 to 400 base pairs long, are derived from unique nonrepetitive sequence, and are enriched in the 5'-untranslated regions of genes, exons, and CpG islands. Chromosomal loci that are enriched sources of microDNA in the adult brain are somatically mosaic for microdeletions that appear to arise from the excision of microDNAs. Germline microdeletions identified by the "Thousand Genomes" project may also arise from the excision of microDNAs in the germline lineage. We have thus identified a previously unknown DNA entity in mammalian cells and provide evidence that their generation leaves behind deletions in different genomic loci.
Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA, USA.
SourceScience (New York, N.Y.) 336:6077 2012 Apr 6 pg 82-6
MeSH5' Untranslated Regions
Cell Line, Tumor
Mice, Inbred C57BL
Molecular Sequence Data
Polymerase Chain Reaction
Repetitive Sequences, Nucleic Acid
Pub Type(s)Journal Article
Research Support, N.I.H., Extramural