Genomic characterisation and fine mapping of the human SOX13 gene

SOX13 is the member of the SOX ((S) under bar ry related HMG B<(OX)under ba r>) family of transcription factors which encodes the type-1 diabetes autoa ntigen, ICA12, and is expressed in a number of tissues including pancreatic islets and arterial walls. By fluorescence in situ hybridisation, radiatio n hybrid mapping and YAC analysis we determined that the human SOX13 gene m aps to Chromosome 1q31.3-32.1 near the marker D1S504, a region associated w ith type-1 diabetes susceptibility and familial dilated cardiomyopathy. Mou se Sox13 maps to the syntenic region near the marker D1Mit57. The human SOX 13 gene spans > 15.5 kb of genomic DNA and is composed of 14 exons with int rons interrupting regions encoding the HMG DNA binding domain and the leuci ne zipper/glutamine-rich dimerisation domain. Comparison with the mouse Sox 13 gene suggests the existence of long and short forms of the SOX13 protein which may arise by differential splicing during different stages in embryo genesis. The high sequence conservation between human SOX13 and mouse, Xeno pus and trout orthologues implies a conserved function in vertebrates. SOX1 3 belongs to SOX Group D members which contain a leucine zipper/glutamine-r ich region. Phylogenetic analyses of SOX proteins suggest that such domains were acquired after the initial divergence of groups A to G. (C) 2000 Publ ished by Elsevier Science B.V. All rights reserved.