DIFFERENTIAL EXPRESSION OF 2 GAP JUNCTION PROTEINS IN CORNEAL EPITHELIUM

Two distinct gap junction proteins (connexins) are expressed in rat co rneal epithelium in a way which parallels cellular differentiation pro cesses in this tissue. Connexin43 is restricted predominantly to the b asal cells of the corneal epithelium and is present in significantly r educed amounts compared to the situation in the adjacent conjunctival epithelium. In contrast, a gap junction protein recognized by antibodi es against MP70 which is the ovine homolog of mouse connexin50, is str ongly expressed in the corneal epithelium and is present in the basal cells, wing cells and surface cells. While the functional significance of this differential expression of corneal epithelial connexins has y et to be established, the corneal epithelium is the third avascular ti ssue besides lens and heart valves which expresses a gap junction prot ein recognized by anti-MP70 antibodies.