For example, in the rat, the misexpression of Hoxa1 leads to ectopic differentiation of vestibuloacoustic (VII) motor neuron in rhombomere
This enhancer region has been shown to direct chick and mouse Hoxa2 gene expression in rhombomeres
3 and 5 of the hindbrain and the pharyngeal arches.
This bidirectional Eph/ ephrin signaling between cells is fundamentally involved in developmental processes that require organized patterning and movement of cells, such as axonal guidance, patterning of hindbrain rhombomeres
, and maintenance of cellular boundaries in the development of the central nervous system (3) or in the remodeling of blood vessels (4).