title: Extrachromosomal microDNAs and chromosomal microdeletions in normal tissues.
abstract: 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.
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, VA, USA.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Shibata
authors.forename: Pankaj
authors.initials: P
authors.lastname: Kumar
authors.forename: Ryan
authors.initials: R
authors.lastname: Layer
authors.forename: Smaranda
authors.initials: S
authors.lastname: Willcox
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Gagan
authors.forename: Jack D
authors.initials: JD
authors.lastname: Griffith
authors.forename: Anindya
authors.initials: A
authors.lastname: Dutta
mesh_terms: D020121:5' Untranslated Regions; D000818:Animals; D020029:Base Pairing; D001483:Base Sequence; D001921:Brain / Q000196:embryology*; D001923:Brain Chemistry; D002460:Cell Line; D045744:Cell Line, Tumor; D002872:Chromosome Deletion; D002877:Chromosomes, Human / Q000235:genetics*; D033481:Chromosomes, Mammalian / Q000235:genetics*; D018899:CpG Islands; D004261:DNA Replication; D004270:DNA, Circular / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D005091:Exons; D005854:Germ Cells / Q000737:chemistry; D006321:Heart / Q000196:embryology; D006801:Humans; D008099:Liver / Q000737:chemistry / Q000196:embryology; D051379:Mice; D008810:Mice, Inbred C57BL; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D012091:Repetitive Sequences, Nucleic Acid
chemical_list: D020121:5' Untranslated Regions; D004270:DNA, Circular