138 - Spatial and Temporal Patterning of the Tracheal Cartilages

Poster Board Number: 138
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Abstract Body : In all vertebrates, the tracheal cartilages support the airways and plays a crucial function in ensuring that air flows to lungs. This study examines the patterning of when these cartilages develop in avian embryos. Through a careful whole-mount and histological analysis, we mapped the onset of cartilage differentiation and the morphology of these cartilages in chicken embryos. Our data shows that the tracheal cartilages are complete rings unlike in mammals, and that they develop simultaneously along the trachea. Cartilage bridges connecting individual rings were observed during their early development. After mapping the onset of cartilage development, we next mapped the expression of cartilage markers (e.g. BMP2), and determined their early expression prior to overt cartilage differentiation. With this knowledge, we implanted filters and beads soaked in a BMP inhibitor into embryos in vivo. These results directly show the role of BMPs in maintaining the shape of the cartilage rings. This study has implications for the treatment of tracheal disorders, such as tracheal agenesis and tracheomalacia. It is the first study to describe the earliest development and morphogenesis of the tracheal cartilages in avian embryos.