Diencephalon/Mesencephalon Homeobox Protein 1 (DMBX1)

OTX3 is a homeodomain transcription factor that is structurally and functionally related to OTX1 and OTX2, both of which are critical in brain morphogenesis. The deduced human protein shares approximately 94% sequence identity with the mouse protein. Northern blot analysis of rat tissues detected a single abundant transcript of 4.3 kb only in MIN6 and adult cerebellum. RT-PCR with Otx3-specific primers demonstrated expression in adult pancreatic islets. The Otx3 transcript was detected from 10.5 to 13.5 days postcoitum in mouse embryos, overlapping the temporal expression pattern of Otx1 and Otx2. In situ hybridization studies demonstrated that Otx3 expression is craniocaudally more restricted than that of Otx1 or Otx2, showing the most intense signal at the midbrain-hindbrain boundary.