Characterisation of Shh gene expression in the skin and feather follicles of Jilin white geese during early embryonic development

1. The Sonic Hedgehog (Shh) gene expresses a highly conserved signalling molecule essential for cell-to-cell communication, which regulates key biological processes, such as embryonic development (as embryo days; ED) and organogenesis. Although feathering is a critical aspect of skin development in poultry, particularly in Chinese indigenous breeds such as the Jilin white goose, its molecular mechanisms remain poorly understood.2. In this study, 150 fertilised Jilin white goose eggs were analysed to investigate embryonic skin morphological changes. Immunohistochemistry (IHC) was applied to determine the localisation of Shh protein, while qPCR and Western blotting were conducted to examine the temporal dynamics of mRNA and protein expression.3. The results revealed that Shh mRNA expression increased initially and then declined between ED8 and ED13, with the highest level observed at ED12. In contrast, Shh protein expression demonstrated a biphasic rise with an intervening decline, peaking at ED9.4. In vitro skin tissue culture experiments indicated that Shh may contribute to feather bud initiation and development by modulating the WNT signalling pathway.5. This study elucidated the temporal and spatial expression patterns of Shh and its interaction with the WNT signalling pathway during early embryonic skin development in Jilin white geese.