Open questions: Chromosome condensation - Why does a chromosome look like a chromosome?
Chromosome Segregation Laboratory, Cancer Research UK London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
BMC Biology 2013, 11:9 doi:10.1186/1741-7007-11-9Published: 31 January 2013
First paragraph (this article has no abstract)
The x-shaped appearance of a chromosome in mitosis has become one of the iconic symbols of the life sciences (Figure 1). DNA takes its chromosome shape only during cell division, but for that time, the compaction of the genomic DNA is critical. The human genome consists of several meters of DNA: even divided between 46 chromosomes, this still leaves several centimeters to be packed into each chromosome. One might be tempted to invoke a magician's hand at work to package centimeters of DNA into a micrometer-sized chromosome. But of course, there is no magic in biology. Nor is there, yet, an answer to the question of how it is done.