Comparative testicular transcriptomic analysis reveals hub genes and pathways regulating semen quality in Zhedong white ganders (Anser cygnoides).

Semen quality is a critical determinant of reproductive efficiency in poultry, yet its molecular regulation remains poorly understood. To identify key genes associated with semen quality in ganders, individuals were stratified into high (H) and low (L) semen quality groups based on a composite sperm quality factor (SQF). Cross-group comparisons of semen parameters, testicular histomorphology, and external genitalia morphology were conducted, followed by high-throughput transcriptomic analysis of testicular tissue. The H group exhibited significantly superior semen quality, testicular development, and external genitalia morphology compared to the L group (P < 0.01). Transcriptomic profiling identified 3,334 differentially expressed genes (DEGs), with 1,552 upregulated and 1,782 downregulated in the H group. GO enrichment analysis revealed that DEGs were primarily involved in biological processes related to cell adhesion, cell differentiation, steroid biosynthetic process, and calcium ion binding. KEGG pathway enrichment analysis further identified ECM-receptor interaction, calcium signaling, and Wnt signaling pathways as potential key regulatory pathways underlying semen quality differences between groups. Protein-protein interaction (PPI) network analysis further identified 11 hub genes (COL1A1, HGF, COL1A2, ITGA5, NGFR, TWIST1, COL6A2, DKK1, BMP7, WNT2, and CYP11A1) with potential roles in spermatogenesis. These findings elucidate the molecular basis for semen quality differences in ganders, advance avian reproductive biology research, and identify potential selective breeding markers to enhance commercial goose production efficiency.