Endoreduplication and development: rule without dividing?

Endoreduplication, a strategy to amplify nuclear DNA without cell division, is very common but poorly understood in plants. Recent findings in Drosophila provide a first picture of the molecular mechanism, which appears to be conserved between plants and animals. In Arabidopsis, the study of trichomes, leaf epidermis and hypocotyl cells sheds new light on the developmental regulation of this process, and its relation to cell expansion.