A Fresh Look on T-Box Factor Action in Early Embryogenesis (T-Box Factors in Early Development).

T-Box transcription factors are expressed throughout the gestational period and coordinate a variety of embryonic events that enable proper development, from the first differentiation of embryonic and extraembryonic tissues until final organogenesis. Although the T-Box gene family comprises essential roles in early cellular differentiation, in adult tissues it has also been associated with cancer development. In spite of their common T-Box regulatory binding domain, T-Box family members utilize different cofactors and different spatiotemporal expression patterns to confer their specificity in diverse developmental processes. The earliest expression note of T-Box factors can be observed even before fertilization in primordial germ cells and just after zygotic gene activation (around the eight-cell blastomere stage). Thus, particularly the early stages of development are highly influenced by these key regulators in line with the notion that T-Box mutations lead to developmental disorders and even lethality. In this review, we summarize recently acquired findings on T-Box factors to provide a comprehensive overview on their role during early embryogenesis.