Heart Development and T‐box Transcription Factors: Lessons from Avian Embryos

Abstract

Abstract Members of the T‐box (Tbx) family of transcription factors have diverse regulatory functions in the developing heart and are associated with several human genetic syndromes that include cardiac malformations. Studies in chicken embryos and other animal model systems have been used to define T‐box gene regulatory networks important for heart formation with parallels in limb outgrowth and patterning. In the heart, T‐box gene regulatory networks function in early cardiac lineage diversification and morphogenesis as well as in valvuloseptal development and conduction system maturation. These regulatory networks include inductive interactions with developmentally important signaling pathways and regulation of downstream target gene expression in complexes with other cardiac transcription factors. An additional feature of cardiac T‐box gene networks is complex regulatory relationships among multiple T‐box genes expressed in a given cell type. The focus of this chapter is T‐box family members and the regulatory networks that control diverse aspects of heart development with particular emphasis on experimental embryological approaches in the chicken model system.