Unequal Shares

Organising, maintaining and replicating DNA is a complex process, and any problems can have severe repercussions. In human cells, DNA is normally packaged into 46 structures, or chromosomes; each time a cell divides, these chromosomes are aligned, replicated, then symmetrically pulled apart into each of the daughter cells. Errors in this process generate cells with an abnormal number of chromosomes, a phenomenon known as aneuploidy. A common cause of miscarriages and birth defects when it occurs in reproductive cells, aneuploidy also arises in cancer cells. It then often leads to further chromosome instability, causing an unequal distribution of chromosomes during subsequent cell divisions – in the example here, one chromosome lags behind in the division process and is then incorrectly sorted. Aneuploidy and chromosome instability in cancerous cells may be linked to advantages such as greater drug resistance, so a better understanding of these processes is essential to developing effective treatments.

Written by Emmanuelle Briolat

Emmanuelle Briolat

Writer

A researcher specialising in visual signals in Lepidoptera, camouflage and the effects of light pollution, Emmanuelle’s writing covers a range of topics, from biomedical research to children’s books about moth defences.

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• Video from work by Daniela Cimini and colleagues
• Virginia Tech, USA
• Originally published under a Creative Commons Licence (BY 4.0)
• Research published in eLife, May 2015