Hox Genes in the Limb: A Play in Two Acts

The development of the tetrapod limb depends on complex cascades of gene expression. In her Perspective, [Deschamps][1] reports on a new study ([ ZAikAiny et al .][2]) that dissects the expression patterns and functions of the HoxD gene cluster during the early stages of limb bud development in the mouse. [1]: http://www.sciencemag.org/cgi/content/full/304/5677/1610 [2]: http://www.sciencemag.org/cgi/content/short/304/5677/1669