T-Genes and limb bud development

The T-box family of transcriptional factors is ancient and highly conserved among most species of animals. Haploin-sufficiency of multiple T-box proteins results in severe human congenital malformation syndromes, involving cramofacial, cardiovascular, and skeletal structures. These genes have major roles in embryogenesis, including the development of the limbs. Formation of the limbs begins with a limb bud and its morphogenesis requires complex epithelial-mesenchymal interactions. Recent studies have shown that T, Tbx2, Tbx3, Tbx4, Tbx5, Tbx15, and Tbx18 are all expressed in the mental functions. The study of these genes is clinically relevant as mutations in several of them cause human congenital malformation syndromes. Furthermore, understanding the function and biology of these genes is important in understanding normal embryogenesis. (c) 2006 Wiley-Liss, Inc.