DEVELOPMENTAL EXPRESSION OF A NOVEL MURINE HOMEOBOX GENE (CHX10) - EVIDENCE FOR ROLES IN DETERMINATION OF THE NEURORETINA AND INNER NUCLEARLAYER

Few potential regulatory proteins of vertebrate retinal development ha ve been identified. We describe a 39 kDa murine polypeptide (Chx10) wi th a homeodomain 82% identical to that of the nematode protein ceh-10. In the developing mouse, the Chx10 transcript is expressed throughout the anterior optic vesicle and all neuroblasts of the optic cup. In t he mature retina, the Chx10 protein is restricted to the inner nuclear layer, in which its expression decreases from the outer to the inner margin. Chx10 transcripts are also detected in regions of the developi ng thalamus, hindbrain, and ventral spinal cord. The data suggest that Chx10 plays critical roles in the formation of the neuroretina and in the development and maintenance of the inner nuclear layer.