Cloning, mapping, and expression analysis of TBX15, a new member of the T-box gene family

The T-box gene family has been conserved throughout metazoan evolution and codes for putative transcription factors that share a uniquely defining DNA-binding domain. We have previously uncovered six mouse T-box genes with discrete spatial and temporal patterns of expression during embryogenesis. Here, we report a novel mouse T-box gene, Tbx15. The Tbx15 gene produces a 3.7-kb transcript with an open reading frame coding for a polypeptide with 602 amino acid residues. Phylogenetic analysis places the Tbx15 gene into a T-box subfamily that also includes mouse Tbx1, Drosophila H15, and nematode Ce-tbx-la genes. We have mapped mouse Tbx15 to chromosome 3, at a position 49 cM from the centromere. During development, Tbx15 transcripts are first detected at embryonic day 9.5. The gene is expressed primarily in the cranio-facial region and in the developing limbs. An isolated human homolog, TBX15, has been mapped by in situ hybridization to chromosomal band 1p13. TBX15 appears to be an excellent candidate for the dominantly expressed acromegaloid facial appearance syndrome, which also maps to the short arm of human chromosome 1 and, like TBX15, is expressed prominently in the eyebrow regions. (C) 1998 Academic Press.