Mesodermal FGF and BMP Govern the Sequential Stages of Zebrafish Thyroid Specification

By analyzing Pax2a and Nkx2.4b expression dynamics in relation to endodermal FGF and BMP signaling activities in zebrafish embryos, researchers identified a Pax2a-expressing thyroid progenitor population that shows enhanced FGF signaling but lacks Nkx2.4b expression and BMP signaling.