Origin of the ultimobranchial body cyst: T/ebp/Nkx2.1 expression is required for development and fusion of the ultimobranchial body to the thyroid
Article first published online: 7 DEC 2005
Copyright © 2005 Wiley-Liss, Inc.
Special Issue: Craniofacial Development Special Issue
Volume 235, Issue 5, pages 1300–1309, May 2006
How to Cite
Kusakabe, T., Hoshi, N. and Kimura, S. (2006), Origin of the ultimobranchial body cyst: T/ebp/Nkx2.1 expression is required for development and fusion of the ultimobranchial body to the thyroid. Dev. Dyn., 235: 1300–1309. doi: 10.1002/dvdy.20655
- Issue published online: 19 APR 2006
- Article first published online: 7 DEC 2005
- Manuscript Accepted: 3 NOV 2005
- National Cancer Institute
- Center for Cancer Research
- T/ebp-null mouse;
- ultimobranchial body;
- ultimobranchial body cyst;
The ultimobranchial body (UBB) is an outpocketing of the fourth pharyngeal pouch that fuses with the thyroid diverticulum, giving rise to calcitonin-producing C-cells. In this study, we demonstrate that the UBB is composed of two types of cells: one expressing T/ebp/Nkx2.1 and the other expressing p63. The former cell type, accounting for a majority of the UBB, requires T/ebp/Nkx2.1 for their survival. In contrast, the p63-positive cells, even in the absence of T/ebp/Nkx2.1 expression, can proliferate and give rise to a vesicular structure that is lined by a monolayer of p63-negative cells, surrounded by a cluster and/or single layer of p63-positive cells, displaying the basal/stem cell phenotype. T/ebp/Nkx2.1 haploinsufficiency causes abnormal fusion of the UBB with the thyroid diverticulum, which stays as a cluster of C-cells around the vesicular structure, similar to the one observed in mice null for T/ebp/Nkx2.1 expression. These results demonstrate that T/ebp/Nkx2.1 plays a role in the survival of UBB cells, their dissemination into the thyroid diverticulum, and the formation of UBB-derived vesicular structure. Developmental Dynamics 235:1300–1309, 2006. © 2005 Wiley-Liss, Inc.