Sex Identification of Feather Color in Geese and the Expression of Melanin in Embryonic Dorsal Skin Feather Follicles

SIMPLE SUMMARY: Plumage color is one of the economic characteristics of poultry. The most common plumage colors in adult geese are white and grey, so research on goose plumage color is relatively scarce compared with the molecular basis of research on chicken plumage color inheritance. Nevertheless, whether the formation of a black phenotype on the Holdobaggy geese newborn dorsal plumage color is associated with gender needs further profound study. Our study researched the gender identification of the newborn Holdobaggy geese based on plumage color and the expression levels of relative genes for melanin, which offers a theoretical basis for gender identification. ABSTRACT: In production practice, we have found that the gray and black down on the backs of the Holdobaggy goslings is usually darker in females than in males. Melanin is the key pigment affecting the color of poultry plumage. Therefore, to determine whether the darkness of the dorsal plumage of the Holdobaggy goslings is related to sex, we study the melanin in the feather follicles of the dorsal skin during the embryonic period. The feather follicle structure and melanin distribution on the dorsal surface of the goose embryo is observed by HE staining and melanin-specific staining. The melanin content in the feather follicles of the dorsal skin of goslings is determined by ELISA. The results showed that the melanin content is higher in female geese than in males (p < 0.05). In addition, we also analyze the mRNA and protein expression levels of melanin-related genes (TYRP1 and ASIP) by quantitative real-time PCR and Western blotting analysis. The results show that the mRNA expression level of TYRP1 is significantly higher in the females’ dorsal skin feather follicles (p < 0.05), while the mRNA expression level of ASIP is significantly higher in the dorsal skin feather follicles of male geese (p < 0.05). In conclusion, the difference between males and females in the color of the black feathers on the dorsal track of the Holdobaggy goslings is verified, and it is feasible to identify the sex by the initial plumage color.