The distribution of J1/tenascin and its transcript during the development of the avian cornea

J1/tenascin is a glycoprotein that is associated with mesenchymal cell motility and proliferation in a variety of embryonic systems. Immunohistochemistry and Western blotting were used to determine if J1/tenascin is present in developing eye tissues, especially in the developing cornea at the times when the neural crest-derived precursors of the corneal endothelium and keratocytes invade the corneal anlage. Anti-J1/tenascin staining was found in both the primary and secondary corneal stromata, Descemet's membrane, the lens capsule, and in the vitreous body. The distribution of J1/tenascin appears to be limited to a subset of eye matrix that is stained by anti-fibronectin. The cellular origin of J1/tenascin was determined by in situ hybridization. J1/tenascin transcript was detected in the developing corneal endothelium, in corneal fibroblasts just before and during their migration, in the ciliary body, and in the lens. This supports the notions that migrating cells synthesize J1/tenascin as they migrate through matrices rich in collagen and fibronectin, and that some epithelia are also a source of J1/tenascin.