Inhibition of condensation in human chromosomes induced by the thymidine analogue 5-iododeoxyuridine.
Human lymphocyte cultures were treated with iododeoxyuridine. This 5-halogenated thymidine analogue induces distinct undercondensations of the heterochromatin of human chromosome 9. The condensation of the other heterochromatic regions on chromosomes 1, 15, 16 and Y is also inhibited, but to a lesser extent. Optimum cell culture conditions required for the induction of undercondensations were determined. Up to 90% of mitotic cells reveal chromosome 9 heterochromatin decondensations when the substance is present in quantities of 1 x 10(-4) M during the last 7 h before cell fixation. In addition, examples of the usefulness of 5-IUDR in the analysis of chromosome aberrations involving chromosome 9 are presented. The interaction between 5-IUDR and chromosomal DNA, the modification of chromosomal proteins and factors inducing chromosomal decondensations are discussed.
Ott
G
G
Institute of Pathology, University of Würzburg, Germany.
Haaf
T
T
Schmid
M
M
D002478:Cells, Cultured; D002877:Chromosomes, Human; D006570:Heterochromatin / Q000235:genetics; D006801:Humans; D007065:Idoxuridine / Q000494:pharmacology*; D007621:Karyotyping; D008214:Lymphocytes / Q000378:metabolism; D008297:Male; D008677:Metaphase; D013936:Thymidine / Q000031:analogs & derivatives*
D006570:Heterochromatin; D007065:Idoxuridine; D013936:Thymidine