COLINEARITY AND FUNCTIONAL HIERARCHY AMONG GENES OF THE HOMEOTIC COMPLEXES

Homeotic genes identify structures along the anterior to posterior axi s during the development of most animals. These genes are clustered in to complexes, and their positions within the cluster correlates with t heir time of expression and the positions of the anterioposterior boun daries of their expression domains. Functional analysis have revealed that this specific genetic order also coincides with a functional hier archy among members of these complexes, so that the products of more p osterior genes in the cluster tend to be prevalent over those of more anterior genes.