Study of Molecular Docking and Evolutionary Dynamics of the FGF Gene Family in Nile Tilapia

The Fibroblast Growth Factor (FGF) gene family of Nile tilapia plays a central role in environmental adaptation and aquaculture resilience. This study integrated in silico analyses and molecular docking to comprehensively analyze the FGF gene family in Nile tilapia. Phylogenetic reconstruction identified three clades (A-C): In Group A, the subclade of genes (FGF19/21/23) revealed conserved endocrine and metabolic roles. Group B genes (FGF7/8a/8b/17/18/24) retained ancestral development functions linked to teleost-specific genome duplication. In Group C, the subclade of genes (FGF1/2/5) exhibiting sub-functionalization, such as FGF2 wound healing versus FGF5 mitogenic roles. The structural analysis highlighted the conserved β-trefoil domain, critical for receptor binding, alongside lineage-specific innovation like heparin-binding motifs in FGF. Physicochemical properties observed a high aliphatic index (AI) of 101.68 in FGF19, which is crucial for climate adaptation. Molecular docking revealed novel predicted interactions, such as FGF4/17 with androgen receptor (AR), potentially influencing male reproduction, while KLF5/DDBI binding expanded FGF roles to gill regeneration and oxidative damage mitigation. Glucocorticoid (GR) exhibited the most potent predicted interaction with a high docking score (- 233.99 to - 313.15), particularly for FGF4 (- 310.86), and FGF8a (- 313.15), suggesting conserved GR-mediated regulation for metabolism, inflammation, and tissue repair. This study pioneers the exploration of potential cross-talk between FGF proteins and nuclear receptors, and provides insights into the link between FGF structural evolution and aquaculture resilience. By bridging genomic features and environmental adaptation, this research contributes to a better understanding of Nile tilapia's potential as a model for sustainable aquaculture.