Analysis of radiation-induced micronuclei in two-cell human-hamster embryos using telomeric and centromeric FISH probes.
Simultaneous, fluorescent in situ hybridization using a centromeric human alpha satellite DNA probe and a telomeric DNA probe was used to analyze the chromosome content of micronuclei induced in two-cell human-hamster embryos by in vitro gamma-ray irradiation of human spermatozoa. In unirradiated samples, about 26% of micronuclei were centromere positive, indicating that both structural chromosome aberrations and numerical changes are involved in the spontaneous production of micronuclei. After exposure of spermatozoa to radiation, a significant increase in the number of micronuclei was found. About 77% of induced micronuclei contained only telomeric signals suggesting that they originated from acentric fragments. However, both centromere-positive and centromere-negative micronuclei increased with radiation dose. These results are consistent with the well known clastogenic effect of ionizing radiation and with its weak aneugenic effect.
Department de Biologia Cel.lular i Fisiologia, Universitat Autònoma de Barcelona, Bellaterra, Spain.
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L
Tusell
R
R
Alvarez
A
A
Genescà
M R
MR
Caballín
R
R
Miró
J
J
Egozcue
D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D002503:Centromere / Q000235:genetics*; D002875:Chromosomes / Q000187:drug effects; D002970:Cleavage Stage, Ovum / Q000648:ultrastructure*; D006224:Cricetinae; D004276:DNA, Satellite / Q000032:analysis; D003703:Demecolcine / Q000494:pharmacology; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008214:Lymphocytes / Q000648:ultrastructure; D048629:Micronuclei, Chromosome-Defective / Q000235:genetics* / Q000528:radiation effects; D012680:Sensitivity and Specificity; D016615:Telomere / Q000235:genetics*
D000972:Antineoplastic Agents, Phytogenic; D004276:DNA, Satellite; D003703:Demecolcine