[Enhanced intensity of polycentric chromosome formation in cells with micronuclei exposed to 5-bromodeoxyuridine under prolonged hyperthermia at 40 degrees C].

The formation of polycentric chromosomes in metaphases of the first mitotic division of polykaryocytes containing micronuclei, under 5-BrdU treatment in the condition of a prolonged hyperthermia was studied. It was shown that the enhance of the frequency of polycentric chromosomes at 40 degrees C was statistically reliable. These data propose the existence of an enzymatic mechanism of disrupting the chromosomal ends at mitosis at the optimal condition (37 degrees C). In cells with micronuclei, under 5-BrdU treatment at 40 degrees C, this mechanism undergoes, presumably, a partial inhibition leading to the enhanced frequency of chromosomes with fused telomeres.