Brachyury and the T-box genes.

Brachyury, or T, is the founder member of a family of transcription factors that share the so-called T-box-a 200 amino acid DNA-binding domain. Recent work has addressed the regulation of Brachyury expression and its function in the embryo. New T-box family members have been found in vertebrate and invertebrate embryos and the importance of this gene family is illustrated by the discovery that mutations in human TBX5 are responsible for Holt-Oram syndrome, which is characterised by abnormalities in heart and forelimb development.