Inhibition of condensation of human Y chromosome by the fluorochrome Hoechst 33258 in a mouse-human cell hybrid.
The fluorochrome Hoechst 33258 which binds preferentially to A-T base pairs, drastically inhibits the condensation of A-T-rich centromeric heterochromatin regions in mouse cell lines. The condensation of all other regions of these chromosomes is also inhibited to some extent. The human Y chromosome contains a large heterochromatic region, which is also rich in A-T base pairs. This chromosome is not affected by Hoechst 33258 in human leukocyte cell cultures. On the other hand, condensation of the multiple copies of human Y chromosome in the mouse-human cell hybrid RH-28Y-23 is inhibited and the chromosomes appear distorted in Hoechst 33258-treated cells.
D000818:Animals; D001562:Benzimidazoles / Q000494:pharmacology*; D006690:Bisbenzimidazole / Q000494:pharmacology*; D002460:Cell Line; D006570:Heterochromatin / Q000378:metabolism*; D006801:Humans; D006822:Hybrid Cells / Q000648:ultrastructure; D008297:Male; D051379:Mice; D012730:Sex Chromosomes / Q000187:drug effects*; D014998:Y Chromosome / Q000187:drug effects*
D001562:Benzimidazoles; D006570:Heterochromatin; D006690:Bisbenzimidazole