Boning Up on Hox Genes

In vertebrate development, the Hox genes, which establish patterns and encode positional information, are found in groups of paralogs. Mutations in individual mouse Hox genes can perturb skeletal elements, but the variable expressivities and penetrance observed with mutations in paralogous Hox genes make it hard to distinguish whether these genes cause patterning at the global or local level. Wellik et al. now report targeted disruptions of all of the alleles of the Hox10 or Hox11 paralogous family to show that Hox genes act in globally patterning of the lumbosacral region of the axial skeleton and are integral in patterning principal elements of the limbs. D. M. Wellik, M. R. Capecchi, Hox10 and Hox11 genes are required to globally pattern the mammalian skeleton. Science 301, 363-367 (2003). [Abstract] [Full Text]