Science Paper

Title: Chromosome segregation errors as a cause of DNA damage and structural chromosome aberrations.

Tumour cells show two types of genetic instability: 1. DNA damage leads to instability at the structural DNA level resulting in changes at the nucleotide level or larger structural chromosomal aberrations such as translocations, deletions, inversions. 2. Chromosomal Instability (CIN) with frequent loss or gain of whole chromosomes due to chromosome segregation  errors in mitosis. These two types of genetic instabilities are thought to occur independently of each other. In the study by Jansen et al. researchers from University Medical Center Utrecht (Aniek Janssen, Geert Kops, Rene Medema)  from the Department of Molecular Cell Biology of the Leiden University Medical Center ( Marja van der Burg, Karoly Szuhai) have provided evidence that chromosome segregation errors can result in double strand DNA breaks. Their results suggest a direct link between CIN and structural chromosomal aberrations and imply that CIN has the potential of increasing tumorigenic capacity of a cell. (Science 30 September 2011:vol. 333 no. 6051 pp. 1895-1898)

Karyotype of a control cell

Karyotype of a cell after Mps1 inhibition

Lagging chromosome in a cleavage furrow:

Actin (red) DAPI (blue) stains

DAPI staining