Centromere: absence of DNA replication during chromatid separation in human fibroblasts.
Cultures of human fibroblasts were labeled briefly with tritiated thymidine and fixed; autoradiographs were made and exposed for 3(1/2) months. No labeling was noted over the centromere of metaphase or anaphase chromosomes. The technique was sensitive to replication at the centromere of a DNA helix only 2.5 microns long, considerably shorter than the estimated length of a replicon in humans. This suggests that chromatid separation during mitosis is not associated with delayed replication of a short segment of chromosomal DNA.
D001345:Autoradiography; D002455:Cell Division; D004247:DNA / Q000096:biosynthesis*; D005260:Female; D005347:Fibroblasts; D006801:Humans; D066298:In Vitro Techniques; D012867:Skin; D013936:Thymidine / Q000378:metabolism*; D014316:Tritium
D014316:Tritium; D004247:DNA; D013936:Thymidine