Chromosomes in the ‘hood

It is almost unbearable (at least for scientists) to contemplate a complete lack of order. So, it comes as some relief that chromosomes may be positioned nonrandomly in the nucleus, thus giving rise to more frequent translocations between certain chromosomes.

The seeming chaos of mitosis led most researchers to believe that any such order would have to be reestablished after each division. But now Daniel Gerlich, Roland Eils (German Cancer Research Center, Heidelberg, Germany), Jan Ellenberg (EMBL, Heidelberg, Germany), and colleagues have found that positioning is maintained through mitosis by a timing mechanism.

Congressing chromosomes make a beeline for the metaphase plate, the group found, and thus preserve information about their relative position perpendicular to the spindle axis. But congression erases information about how far the chromosomes had to travel to reach the metaphase plate. Despite this,...