Role of Jagged1-Notch pathway in thyroid development.

The zebrafish thyroid gland shows a unique pattern of growth. Despite the lack of a compact gland, the zebrafish thyroid tissue originates from the pharyngeal endoderm and the main genes involved in its patterning and early development are conserved between zebrafish and mammals. In recent years, the research has been focused to the search of novel candidate genes and environmental factors underlying congenital hypothyroidism. Among these, it has been demonstrated that the Notch signalling plays a central role during zebrafish thyroid development. In this review, we will provide an overview of the current knowledge of the distinct roles of the Notch signalling and of the jag1a and jag1b ligands during the different phases of thyroid organogenesis. Furthermore, we will discuss the role of JAG1 variants in congenital thyroid defects.