Seminal plasma androgen-binding protein activity in turkeys with normal white or abnormal yellow semen

Dihydrotestosterone (DHT) binding activity of normal white and abnormal yellow turkey semen was quantitated by disc-gel electrophoresis in the presence of [3H]DHT. White seminal plasma had three peaks of activity (Rf = 0.3, 0.5 and 0.8). Yellow seminal plasma had a greater protein concentration and [3H]DHT binding activity averaging 32.5 +/- 7.93 pmol DHT/ml compared with 1.45 +/- 0.3 pmol DHT/ml for white seminal plasma. The majority of [3H]DHT binding was localized at Rf = 0.5 for the yellow seminal plasma. When labelled samples were separated by electrophoresis on unlabelled gels, the only peak of activity was at Rf = 0.5. Blood serum contained 3 peaks of activity (Rf = 0.4, 0.5, and 0.8). We conclude that a seminal plasma androgen-binding protein is present in the domestic turkey, and in males with yellow semen syndrome androgen-binding activity is increased.