Differential tissue localization of oviduct and erythroid transferrin receptors.

The tissue distributions of the estrogen-inducible hen oviduct transferrin receptor and the chicken embryonic erythrocyte transferrin receptor were studied. Tissue sections were investigated by immunofluorescence microscopy using specific polyclonal antisera against each receptor. The receptor originally identified and characterized in the oviduct strongly stained liver and ovary; localized staining was observed in the brain (especially endothelial cells). Staining of breast muscle and heart tissue occurred only in occasional interstitial cells. Antiserum against oviduct transferrin receptor did not stain erythrocytes, either from embryos or from mature animals. On the other hand, the antiserum directed against the embryonic erythrocyte receptor stained embryonic erythrocytes; it did not stain any other tissues. The fluorescence microscopy observations were confirmed by Western blot analysis. The strong staining of oviduct, liver, and ovary suggests a major role for the oviduct transferrin receptor in oogenesis.