| Some nonlethal regulatory mutations occur in HOX genes in humans, which can result in a cervical rib or polydactyly, an increase in the number of fingers or toes. |
| We have used experimental manipulation of chick embryos to test the causal role of Hox genes in patterning derivatives of the paraxial mesoderm. |
| The Hox genes exert this influence by their action on the genes controlling the development of these structures. |
| Development of the appropriate shapes of the vertebral bodies is regulated by HOX genes. |
| Hox genes have been isolated from a number of cnidarian species including hydra. |
| Across major phylogenetic comparisons, the evolution of Hox clusters generally parallels the evolution of axial complexity. |
