A role for Shh and Bmp4 in regulating the dorsal-ventral patterning of the developing pharyngeal region
Abstract
The pharynx is crucial to the survival of all vertebrates since it facilitates respiration by connecting the nasal and oral cavity to the larynx and digestion by connecting the oral cavity to the esophagus. The developing pharyngeal region displays dorsoventral patterning, and currently there is little information identifying the underlying mechanisms that regulate this patterning. This is in part due to the complexity of the developing pharyngeal region that requires contributions from all three germ layers along with neural crest cells. The expression profiles of Sonic Hedgehog (Shh) and Bone Morphogenetic Protein 4 (Bmp4) adjacent to the developing pharyngeal region are reminiscent of their expression around the developing neural tube where they regulate dorsoventral patterning. By pharmacologically altering these signalling pathways I was able to support the hypothesis that the correct dorsoventral gene expression pattern observed in the developing pharyngeal region is regulated by opposing gradients of Shh and Bmp4.