Cloning and mapping of a human gene (TBX2) sharing a highly conserved protein motif with the Drosophila omb gene.

We have identified and cloned a human gene (TBX2) that exhibits strong sequence homology within a putative DNA binding domain to the drosophila optomotor-blind (omb) gene and lesser homology to the DNA binding domain of the murine brachyury or T gene. Unlike omb, which is expressed in neural tissue, or T, which is not expressed in adult animals, TBX2 is expressed primarily in adult in kidney, lung, and placenta as multiple transcripts of between approximately 2 and 4 kb. At least part of this transcript heterogeneity appears to be due to alternative polyadenylation. This is the first reported human member of a new family of highly evolutionarily conserved DNA binding proteins, the Tbx or T-box proteins. The human gene has been mapped by somatic cell hybrid mapping and chromosomal in situ hybridization to chromosome 17q23, a region frequently altered in ovarian carcinomas.