Tyrosine Hydroxylase-Immunopositive Cells and Melanin in the Mesencephalon of Yugan Black-Bone Fowl

BACKGROUND: The Yugan blackbone fowl (YBF) is a special poultry with hyperpigmentation in various organs, including feather. However, the mechanism of hyperpigmentation is limited, and the melanic information of other organs except skin is rare. AIMS AND OBJECTIVES: In this study, we attempt to get an insight of the mechanism of melanogenesis of birds. MATERIALS AND METHODS: The mesencephalon of YBF was observed by light microscopy with hematoxylineosin and tyrosine hydroxylase (TH) immunohistochemistry. RESULTS: The TH immunopositive cells were found in the mesencephalon. Moreover, the melanin was also observed in the connective tissue of the mesencephalon. CONCLUSION: Our results confirmed the existence of melanin andTH immunopositive cells in the mesencephalon of YBF. These results provide a reference for further study on the mechanism of melanogenesis/hyperpigmentation in birds.