Zebrafish embryo: a new model for studying thyroid morphogenesis

Abstract Thyroid development anomalies, known as thyroid dysgenesis, are the commonest cause of congenital hypothyroidism. Most of the cases remain unexplained, although the occurrence of familial cases strongly suggests a genetic contribution. To validate a genetic implication in thyroid development, animal models are required. Recently, zebrafish has become extensively used due to its numerous advantages. Moreover, thyroid development is similar in zebrafish and in human. However, caution is advised when analyzing results from zebrafish. It is important to keep in mind that phenotype is often divergent from the human when knocking out/down a gene. Furthermore, when a phenotype is observed, it is often accompanied by a vascular phenotype, so maybe it is the vascular anomalies that lead to thyroid disorganization.