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 de fining DNA-binding domain. We have previously uncovered six mouse T-bo x genes with discrete spatial and temporal patterns of expression duri ng 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 co ding for a polypeptide with 602 amino acid residues. Phylogenetic anal ysis places the Tbx15 gene into a T-box subfamily that also includes m ouse Tbx1, Drosophila H15, and nematode Ce-tbx-la genes. We have mappe d mouse Tbx15 to chromosome 3, at a position 49 cM from the centromere . During development, Tbx15 transcripts are first detected at embryoni c day 9.5. The gene is expressed primarily in the cranio-facial region and in the developing limbs. An isolated human homolog, TBX15, has be en mapped by in situ hybridization to chromosomal band 1p13. TBX15 app ears to be an excellent candidate for the dominantly expressed acromeg aloid facial appearance syndrome, which also maps to the short arm of human chromosome 1 and, like TBX15, is expressed prominently in the ey ebrow regions. (C) 1998 Academic Press.