Murine models for the study of thyroid gland development.

Gene targeting technology has allowed the generation of mouse mutants which lack specific genes. These mice represent a valuable tool for identifying the in vivo functions of proteins and for dissecting the pathways that control the development and differentiation of the numerous structures of the body. What we know about thyroid morphogenesis is largely due to studies on murine models generated in gene-targeting experiments. Although several points remain to be elucidated, a number of genes involved in thyroid organogenesis have been identified in recent years. In addition, this information has greatly improved our knowledge of the pathogenetic mechanisms of thyroid dysgenesis in humans. This review summarizes the complex processes leading to thyroid development mostly by describing the phenotype of currently available knockout animals.