Preferential somatic pairing between homologous heterochromatic regions of human chromosomes.
The cytidine analog 5-azacytidine (5-azaC) induces an undercondensation of the heterochromatin in human chromosomes 1, 9, 15, 16, and Y when it is added in low concentrations to the late S-phase of growing lymphocyte cultures. In interphase nuclei, these heterochromatic regions are frequently somatically paired. The somatic pairing configurations are preserved up to metaphase stage in the 5-azaC-treated cultures and are thus susceptible to a direct microscopical examination. The statistical analysis of 1,000 somatic pairing configurations from 5-azaC-treated cells showed that the somatic pairing between the heterochromatic regions of homologous chromosomes is preferred over that between nonhomologous chromosomes.
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Haaf
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Steinlein
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Schmid
D001374:Azacitidine / Q000494:pharmacology; D002877:Chromosomes, Human / Q000187:drug effects / Q000648:ultrastructure; D002900:Chromosomes, Human, 1-3; D002901:Chromosomes, Human, 13-15; D002902:Chromosomes, Human, 16-18; D002906:Chromosomes, Human, 6-12 and X; D006570:Heterochromatin / Q000187:drug effects / Q000648:ultrastructure; D006801:Humans; D007621:Karyotyping; D008214:Lymphocytes / Q000166:cytology / Q000648:ultrastructure; D008297:Male; D008938:Mitosis; D008957:Models, Genetic; D014998:Y Chromosome
D006570:Heterochromatin; D001374:Azacitidine