Hox gene control of neural crest cell, pharyngeal arch and craniofacial patterning">Hox gene control of neural crest cell, pharyngeal arch and craniofacial patterning

Abstract

This chapter highlights the intimate involvement of Hox genes in hindbrain, neural crest cell and pharyngeal arch development where they exert a profound influence on craniofacial morphogenesis. The vertebrate head is an elaborate assemblage of cranial specializations, consisting of the central and peripheral nervous systems, viscero- and neurocranium, muscle, vasculature and connective tissues. Craniofacial development therefore is a complex process that involves the orchestrated spatio-temporal integration of multiple specialized tissues. It is important to understand the mechanisms that control vertebrate head development, as craniofacial anomalies constitute nearly one-third of all human congenital defects. The vertebrate head is shaped by a particular group of cells, called neural crest cells, which are endowed with remarkable differentiative abilities. They are capable of generating diverse components of the head including the skeleton, teeth, peripheral nerves, sensory ganglia, connective tissue, dermis, and pigment cells, among many others. Neural crest cells are at the nexus of several signaling and inducing activities that act to pattern the features of the cranium and face. The chapter discusses recent advances in the understanding the dynamic nature of the genetic and tissue interactions that occur during normal craniofacial development and in particular the patterning roles played by the Hox gene family of transcription factors.