Stacked thin layers of metaphase chromatin explain the geometry of chromosome rearrangements and banding

Research output: Contribution to journalArticleResearchpeer-review

13 Citations (Scopus)

Abstract

The three-dimensional organization of tightly condensed chromatin within metaphase chromosomes has been one of the most challenging problems in structural biology since the discovery of the nucleosome. This study shows that chromosome images obtained from typical banded karyotypes and from different multicolour cytogenetic analyses can be used to gain information about the internal structure of chromosomes. Chromatin bands and the connection surfaces in sister chromatid exchanges and in cancer translocations are planar and orthogonal to the chromosome axis. Chromosome stretching produces band splitting and even the thinnest bands are orthogonal and well defined, indicating that short stretches of DNA can occupy completely the chromosome cross-section. These observations impose strong physical constraints on models that attempt to explain chromatin folding in chromosomes. The thin-plate model, which consists of many stacked layers of planar chromatin perpendicular to the chromosome axis, is compatible with the observed orientation of bands, with the existence of thin bands, and with band splitting; it is also compatible with the orthogonal orientation and planar geometry of the connection surfaces in chromosome rearrangements. The results obtained provide a consistent interpretation of the chromosome structural properties that are used in clinical cytogenetics for the diagnosis of hereditary diseases and cancers.
Original languageEnglish
Article number14891
JournalScientific Reports
Volume5
DOIs
Publication statusPublished - 8 Oct 2015

Fingerprint Dive into the research topics of 'Stacked thin layers of metaphase chromatin explain the geometry of chromosome rearrangements and banding'. Together they form a unique fingerprint.

Cite this