Humangenetik

, Volume 23, Issue 4, pp 235–258

The phenomenon of premature chromosome condensation: its relevance to basic and applied research

  • Karl Sperling
  • Potu N. Rao
Reviews

Summary

Normally the chromosomes of eukaryotic cells are visible only for a brief period during cell division. However, when mitotic cells are fused with interphase cells, a “premature chromosome condensation” (PCC) is induced in the interphase cells. The morphology of the prematurely condensed chromosomes varies according to the position of the interphase cell in the cell cycle: G1-PCC are very long and single-stranded; G2-PCC have two chromatids which are still longer than prophase chromosomes; S-PCC have a “pulverized” appearance, which is obviously due to less condensation of chromatin at the sites of replication.

With this in mind, some older cytological findings can now be interpreted as premature condensation of whole chromosome sets, of single chromosomes, and of chromosomal regions.

Furthermore, the studies on PCC shed new light on the initiation of mitosis and on the condensation-decondensation cycle of chromosomes during interphase.

The application of this new method to mutagenesis and clinical cytogenetics is discussed.

Zusammenfassung

Die Chromosomen eukaryoter Zellen sind normalerweise nur für den kurzen Augenblick der Zellteilung sichtbar. Fusioniert man jedoch Mitosezellen mit Interphasezellen, so wird in den letzteren eine “vorzeitige Chromosomenkondensation” (engl.: premature chromosome condensation, PCC) induziert. Die Morphologie der vorzeitig kondensierten Chromosomen hängt von dem Stadium des Zellcyclus ab, in dem sich die Interphasetehen befinden: G1-Chromosomen sind sehr lange, einsträngige Gebilde, G2-Chromosomen bestehen aus zwei Chromatiden, die noch länger als Prophasechromosomen sind, und S-Chromosomen erscheinen “pulverisiert”, was offensichtlich auf eine stärkere Entspiralisierung des Chromatins an den Replikationsstellen zurückzuführen ist.

Hiernach lassen sich heute einige ältere cytologische Befunde als vorzeitige Kondensation ganzer Chromosomensätze, einzelner Chromosomen und Chromosomenabschnitte interpretieren.

Darüber hinaus haben die Untersuchungen an den vorzeitig kondensierten Chromosomen neue Einblicke in die Initiation der Mitose und den Kondensations-Dekondensations-Cyclus der Chromosomen während der Interphase ergeben.

Die Anwendung dieser neuen Methode auf die Mutationsforschung und die klinische Cytogenetik wird diskutiert.

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Copyright information

© Springer-Verlag 1974

Authors and Affiliations

  • Karl Sperling
    • 1
    • 2
  • Potu N. Rao
    • 1
    • 2
  1. 1.Institut für Genetik der Freien Universität BerlinBerlinGermany
  2. 2.Department of Developmental TherapeuticsThe University of Texas, M.D. Anderson Hospital and Tumor InstituteHouston

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