Localization of connective tissue growth factor (CTGF) and transforming growth factor beta-2 (TGF-β2) during eye development of four species of birds

Connective tissue growth factor (CTGF) and transforming growth factor (TGF-β2) have essential roles for structure, function, growth, and production of extracellular matrix during eye development. The current study aim was to examine the localization of CTGF and TGF-β2 by immunohistochemical labeling during eye development in four different habitat species of Egyptian birds i.e. chicken (Gallus gallus domesticus), duck(Cairina moschata), quail (Coturnix coturnix), and egret (Bubulcus ibis). Fertilized eggs were obtained to access pre-and post-hatching stages of developing eye. CTGF and TGF-β2 were detected in the inner non-pigmented epithelium layer of ciliary body during eye development of studied birds. Moreover, CTGF was well expressed in the developing sclera, but not expressed in the developing retina. On the contrary, expression of TGF-β2 was detected in the developing retina but was not detected in the developing sclera. The pattern of expression and distribution of CTGF and TGF-β2 in ciliary body, retina and sclera concluded the important cellular function of these growth factors during eye development of studied birds.