Periderm invasion contributes to the epithelial lining of the teleost pharynx

• Autor(a) principal: Rosa, Joana
• Data de Publicação: 2019
• Outros Autores: Oralova, V, Larionova, D., Eisenhoffer, G. T., Witten, P. E., Huysseune, A.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.1/14329

The gnathostome pharyngeal cavity functions in food transport and respiration. In amniotes the mouth and nares are the only channels allowing direct contact between internal and external epithelia. In teleost fsh, gill slits arise through opening of endodermal pouches and connect the pharynx to the exterior. Using transgenic zebrafsh lines, cell tracing, live imaging and diferent markers, we investigated if pharyngeal openings enable epithelial invasion and how this modifes the pharyngeal epithelium. We conclude that in zebrafsh the pharyngeal endoderm becomes overlain by cells with a peridermal phenotype. In a wave starting from pouch 2, peridermal cells from the outer skin layer invade the successive pouches until halfway their depth. Here the peridermal cells connect to a population of cells inside the pharyngeal cavity that express periderm markers, yet do not invade from outside. The latter population expands along the midline from anterior to posterior until the esophagusgut boundary. Together, our results show a novel role for the periderm as an internal epithelium becomes adapted to function as an external surface.