title: DNA content of micronuclei in human lymphocytes.
abstract: We have calculated the distribution of DNA contents in micronuclei (MN) induced by ionizing radiation in human lymphocytes on two assumptions: the MN arise from acentric chromosome fragments (ACF), and the ACF result from the random breakage and rejoining of chromosomes. Measurements show that about 80 per cent of MN have a DNA content in the range of 0.5-6 per cent of the G1 nucleus. This group is consistent with the model and shows little dependence on radiation dose over the dose range of 0.5-4 Gy, or on lymphocyte culture time, varying from 48 to 76 hours. The MN with DNA content from 6 to 20 per cent of the G1 nucleus are probably the result both of spindle defects and of DNA synthesis in MN.
mesh_terms: D000328:Adult; D002869:Chromosome Aberrations; D003037:Cobalt Radioisotopes; D004247:DNA / Q000097:blood*; D006801:Humans; D066298:In Vitro Techniques; D008214:Lymphocytes / Q000528:radiation effects*; D011831:Radiation Genetics
chemical_list: D003037:Cobalt Radioisotopes; D004247:DNA