An important function of specialised epithelia is to regulate ion homeostasis. Dysfunction of epithelial ion homeostasis can give rise to several human diseases, such as distal renal acidosis (when kidney epithelia are affected) or cystic fibrosis (when lung and gut epithelia are affected). Dubaissi and Papalopulu investigate the use of Xenopus larval skin as a model to study epithelial ion homeostasis, and show that this tissue contains ionocytes that depend on the transcription factor foxi1e for development and are highly similar to intercalated cells of the human kidney. Furthermore, Xenopus ionocytes are required for normal development of multiciliated cells. This work demonstrates the utility of Xenopus larval skin as a model for investigating complex cell interactions in intact tissue.
