Spatiotemporal Immunohistochemical Profiling and Comparative Analysis of HGF, IGF-I, FGF2, and TGF-α Expression in Goose (Anser anser) Kidney and Liver During Embryonic Hatching and Early Post-Hatch Development
Read Abstract
Embryonic organogenesis in avian species is orchestrated through a tightly regulated network of growth factors that govern cellular proliferation, differentiation, migration, extracellular matrix remodeling, and tissue maturation. Among these regulatory molecules, hepatocyte growth factor (HGF), insulin-like growth factor-I (IGF-I), fibroblast growth factor-2 (FGF2), and transforming growth factor-α (TGF-α) represent fundamental signaling mediators involved in renal and hepatic morphogenesis. Although extensive investigations have characterized these factors in mammalian developmental biology, comparatively limited information is available regarding their spatiotemporal immunohistochemical distribution in geese (Anser anser), particularly during the transition from embryonic hatching to early post-hatch development. This review synthesizes current knowledge regarding the developmental anatomy of avian kidney and liver tissues and critically evaluates the reported localization patterns and biological functions of HGF, IGF-I, FGF2, and TGF-α within embryonic and neonatal stages. Comparative evidence from chickens, ducks, quails, rodents, and humans is integrated to establish mechanistic similarities and species-specific differences in organ maturation. Particular emphasis is placed on the coordinated interactions among these growth factors during nephrogenesis, hepatogenesis, epithelial differentiation, vascularization, and metabolic adaptation immediately following hatching. The review further identifies significant gaps in goose-specific immunohistochemical research and proposes future directions involving quantitative immunohistochemistry, molecular validation, and integrative developmental analyses. Collectively, the available evidence demonstrates that coordinated expression of HGF, IGF-I, FGF2, and TGF-α constitutes an essential regulatory network underlying functional maturation of avian renal and hepatic tissues, thereby providing valuable insights for developmental biology, veterinary histology, comparative anatomy, and poultry science.