The identification of micronucleated chromosomes: a possible assay for aneuploidy.
A technique is presented for establishing the presence of kinetochores in micronuclei (mn) using CREST antikinetochore antibodies and immunofluorescence. In cultured lymphocytes blocked in their second cycle by cytochalasin-B 61% baseline mn possess kinetochores, and thus originated from whole chromosomes. Mn-inducing agents with different modes of action were compared to determine the proportion of mn with kinetochores: virtually all X-ray- and mitomycin-C-induced mn were derived from acentric fragments as shown by the absence of kinetochore immunofluorescence, whereas the majority (79%) of colcemid-induced mn were CREST positive, reflecting the formation of mn through failure of attachment of chromosomes to the spindle. The proportion of mn without kinetochore fluorescence in the control (39%) and colcemid-treated (21%) cultures was greater than expected and possible reasons for this are discussed.
Thomson
E J
EJ
MRC Clinical and Population Cytogenetics Unit, Western General Hospital, Edinburgh, UK.
Perry
P E
PE
D000782:Aneuploidy; D002478:Cells, Cultured; D002875:Chromosomes / Q000648:ultrastructure*; D003703:Demecolcine / Q000494:pharmacology*; D004307:Dose-Response Relationship, Radiation; D005455:Fluorescent Antibody Technique; D006801:Humans; D008214:Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000528:radiation effects*; D015162:Micronucleus Tests; D016685:Mitomycin; D008937:Mitomycins / Q000494:pharmacology*; D009154:Mutation; D014965:X-Rays
D008937:Mitomycins; D016685:Mitomycin; D003703:Demecolcine