Expression of gicerin, a cell adhesion molecule, in the abnormal retina insilver plumage color mutation of Japanese quail (Coturnix japonica)

Silver plumage color mutant (B/B) quail has an abnormal retina characterizi ng the transdifferentiation of retinal pigment epithelium (RPE) following t he retinal separation in the early developmental stage. In the present stud y; (i) the expression of gicerin, an immunoglobulin-superfamily cell adhesi on molecule, was examined in the retina of B/B quail. In the wild-type quai l, gicerin protein was enriched in the apical membrane (facing the neural r etina, NR) of RPE cells on embryonic day (E) 4 and then appeared also in NR cei Is from E5. However, in the B/B retina, no gicerin expression was foun d in the transdifferentiation area of RPE prior to the retinal separation. (ii) In addition to this, microinjection of anti-gicerin polyclonal antibod y into the eyeball of wild-type quail on E3 caused the retinal separation a nd induced the transdifferentiation of RPE into new NR. These observations suggest that the decrease of gicerin expression might participate in the re tinal separation and RPE-transdifferentiation in B/B quail. (C) 1999 Elsevi er Science Ireland Ltd. Ail rights reserved.