Differential Expression of E-cadherin, N-cadherin, and P-cadherin Proteins in the Chicken Uropygial Gland During the Post-hatching Growth Period

This study is the first to describe the presence, localization, and temporal distribution of epithelial (E)-, neural (N)-, and placental (P)-cadherins within the chicken uropygial gland (UG) during the post-hatching growth period, using immunohistochemistry and Western blot techniques. In the luminal epithelium and secretory tubules of the UGs of 1-day-old chicks, the germinative layer sebocytes (GLS) exhibited cytoplasmic immunostaining for P-cadherin, while they were negative for E-cadherin. However, the secretory layer sebocytes (SLS) showed a membranous staining for both cadherins. N-cadherin was only localized in the lateral membrane of the end-bulb cells. From the 7th to the 150th day of post-hatching, all cadherins were detected in the membrane of SLS of the luminal epithelium and peripheral and central zones. E- and N-cadherin immunostainings were weak in the cytoplasm of GLS, but P-cadherin was strong. In addition, N-cadherin was strongly localized in the membrane of some GLS of peripheral tubules adjacent to the capsule. These results indicate that the localization patterns of cadherins differ based on the type of cadherin, age, and zones and cell layers of the UG. This suggests that cadherins play unique roles in maintaining tissue architecture and regulating holocrine secretion during the post-hatching growth of chicken UG.