Abstract
Diplochromosomes from colchicine-induced endoreduplicated HeLa cells were analyzed by light and electron microscopy. The patterns of C-, G-, NOR-, and late replicating DNA-rich bands obtained clearly indicate that the four chromatids constituting a diplochromosome are structurally identical and behave the same, at least in terms of replication kinetics and r-DNA transcription. Under the electron microscope, whole-mounted diplochromosomes appeared formed by two completely divided chromosomes showing no physical connection at their centromeric regions. The two chromosomes forming a diplochromosome seem to be held together by chromatin fiber loops connecting the two neighbouring chromatids of the sister chromosomes. These connecting loops clearly decrease in number as chromosome condensation progresses.
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Goyanes, V.J., Schvartzman, J.B. Insights on diplochromosome structure and behaviour. Chromosoma 83, 93–102 (1981). https://doi.org/10.1007/BF00286018
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DOI: https://doi.org/10.1007/BF00286018