Localised inhibition of FGF signalling in the third pharyngeal pouch is required for normal thymus and parathyroid organogenesis.

ABSTRACT: The thymus and parathyroid glands are derived from the third pharyngeal pouch endoderm. The mechanisms that establish distinct molecular domains in the third pouch and control the subsequent separation of these organ primordia from the pharynx are poorly understood. Here, we report that mouse embryos that lack two FGF feedback antagonists, Spry1 and Spry2, display parathyroid and thymus hypoplasia and a failure of these organ primordia to completely separate from the pharynx. We show that FGF ligands and downstream reporter genes are expressed in highly regionalised patterns in the third pouch and that sprouty gene deletion results in upregulated FGF signalling throughout the pouch endoderm. As a consequence, the initiation of markers of parathyroid and thymus fate is altered. In addition,

SUBMITTER: Gardiner JR 

PROVIDER: S-EPMC3424047 | biostudies-literature | 2012 Sep

REPOSITORIES: biostudies-literature