title: [Sharp changes in the copy number of mtDNA and its transcription in the blood cells of X-ray irradiated mice are observed, and mtDNA fragments appear in the blood serum].
abstract: Changes in the number of mitochondrial DNA (mtDNA) copies and alterations in its transcription were followed in the blood cells of mice after their exposure to X-rays; also, extracellular mtDNA fragments were registered in the blood serum of these mice. By a real time polymerase chain reaction (RT-PCR), a sharp increase in mtDNA copy number one hour after the exposure was detected in the blood cells of 1 Gy X-ray irradiated mice. This increase in mtDNA copies is considered as a result of a compensatory reaction developed in mice in response to the radiation damage in a part of mtDNA molecules. Exposure to X-ray radiation at a dose of 10 Gy resulted in an arrest of mtDNA replication in mouse blood cells within three hours after irradiation. At the same time, RT-PCR assays showed that at the same radiation dose, an increase in the number of mtRNA of the mitochondrial nd6 gene relative to mRNA of the nuclear gene gapdh occurs. This indicates that, although mtDNA is more damaged in comparison with nuclear DNA (nDNA), the process of transcription continues in the blood cell mitochondria of mice after their exposure to 10 Gy, whereas the transcription of damaged nDNA is arrested. After the irradiation of mice with 10 Gy, mtDNA fragments of 1841 bp were registered in the blood serum. Thus, in the blood cells of mice exposed to X-rays, the copy number of mtDNA and its transcription are sharply changed, and large mtDNA fragments are observed in the blood serum.
authors.forename: E V
authors.initials: EV
authors.lastname: Evdokimovskiĭ
authors.forename: M V
authors.initials: MV
authors.lastname: Patrushev
authors.forename: T E
authors.initials: TE
authors.lastname: Ushakova
authors.forename: A I
authors.initials: AI
authors.lastname: Gaziev
mesh_terms: D000818:Animals; D001773:Blood Cells / Q000737:chemistry* / Q000378:metabolism / Q000528:radiation effects*; D004272:DNA, Mitochondrial / Q000032:analysis* / Q000097:blood / Q000235:genetics*; D050259:Genes, Mitochondrial / Q000235:genetics; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000235:genetics; D051379:Mice; D008807:Mice, Inbred BALB C; D009245:NADH Dehydrogenase / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D014158:Transcription, Genetic / Q000528:radiation effects*; D014965:X-Rays
chemical_list: D004272:DNA, Mitochondrial; D012333:RNA, Messenger; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D009245:NADH Dehydrogenase; C508029:NADH dehydrogenase subunit 6, mouse