title: Chromosome elimination in micronuclei: a common cause of hypoploidy.
abstract: An excess of hypoploid cells has repeatedly been reported in studies of aneuploidy and has often been attributed to technical artifact. We have examined at least 200 anaphase or early-telophase cells from each of 28 normal women and found that chromosome or chromatid lagging occurs in an average of 2.43% of cells. In a separate study, we have examined the frequency of micronuclei in cytochalasin B-arrested, binucleate cells and shown that a similar frequency of cells (1.6%) contain one or more micronuclei. Using in situ hybridization of an alpha centromeric probe (alpha R1), which hybridizes to 9 of the 22 human autosomes, we were able to infer that most, if not all, of the micronuclei contain whole chromosomes or chromatids. Since the loss of a chromosome by lagging will induce hypoploid daughter nuclei (two where a chromosome is lost and one where a chromatid is lost), we conclude that lagging is a major mechanism for chromosome loss in human lymphocyte cultures. This loss occurs in the cells of normal individuals under control conditions.
authors.affiliation: Genetics Department, Queen Elizabeth Hospital, Woodville, South Australia.
authors.forename: J H
authors.initials: JH
authors.lastname: Ford
authors.forename: C J
authors.initials: CJ
authors.lastname: Schultz
authors.forename: A T
authors.initials: AT
authors.lastname: Correll
mesh_terms: D000705:Anaphase; D000782:Aneuploidy; D002467:Cell Nucleus / Q000648:ultrastructure*; D002872:Chromosome Deletion; D006801:Humans; D008214:Lymphocytes / Q000166:cytology / Q000648:ultrastructure; D008677:Metaphase; D015162:Micronucleus Tests