Fig. 2.

Genomic loci and alternative splicing of Pitx genes in mouse and human. a The Pitx1 locus is located in mouse chromosome 13 and human chromosome 5. Only one transcript coding for one isoform of PITX1 protein has been identified in both species. b The PITX2 protein possesses several different isoforms as a result of alternative splicing and translation sites. The DNA sequence coding for Pitx2 is located in mouse chromosome 3 and human chromosome 4. c The Pitx3 locus is found in mouse chromosome 19 and human chromosome 10 with only one transcript identified in both species. All PITX proteins possess the homeodomain (orange), OAR-motif (cyan) and a nuclear localization signal (green) located within the OAR