7 research outputs found
Corrigendum to âA molecular analysis of neurogenic placode and cranial sensory ganglion development in the shark, Scyliorhinus caniculaâ [Dev. Biol. 304 (2007) 156â181]
Evolution of the hypoxia-sensitive cells involved in amniote respiratory reflexes
textabstractThe evolutionary origins of the hypoxia-sensitive cells that trigger amniote respiratory reflexes â carotid body glomus cells, and âpulmonary neuroendocrine cellsâ (PNECs) -are obscure. Homology has been proposed between glomus cells, which are neural crest-derived, and the hypoxia-sensitive âneuroepithelial cellsâ (NECs) of fish gills, whose embryonic origin is unknown. NECs have also been likened to PNECs, which differentiate in situ within lung airway epithelia. Using genetic lineage-tracing and neural crest-deficient mutants in zebrafish, and physical fate-mapping in frog and lamprey, we find that NECs are not neural crest-derived, but endoderm-derived, like PNECs, whose endodermal origin we confirm. We discover neural crest-derived catecholaminergic cells associated with zebrafish pharyngeal arch blood vessels, and propose a new model for amniote hypoxia-sensitive cell evolution: endoderm-derived NECs were retained as PNECs, while the carotid body evolved via the aggregation of neural crest-derived catecholaminergic (chromaffin) cells already associated with blood vessels in anamniote pharyngeal arches