Identification of Key Genes and Regulatory Pathways Related to Sexual Maturation and Spermatogenesis in the Hypothalamic-Pituitary-Gonadal Axis of Wenchang Roosters Through Transcriptome Analysis

Spermatogenesis in poultry is tightly controlled by the hypothalamic-pituitary-gonadal (HPG) axis, with its efficiency directly impacting semen quality and fertilization rates. Despite the critical role of the HPG axis in avian reproduction, the fundamental molecular mechanisms regulating the sexual maturity and spermatogenesis in roosters remain poorly understood. The objective of this study is to investigate gene expression changes across the HPG axis (hypothalamus, pituitary gland, and testes) during sexual maturation in Wenchang roosters. Results from phenotypic assessments showed a marked testicular development was between 18 and 20 weeks of age. The transcriptome analysis revealed significant DEGs across the hypothalamus, pituitary, and testis, with the testis showing the most pronounced changes (2,154 DEGs; 1,765 upregulated), compared to the hypothalamus (52 DEGs) and pituitary (27 DEGs). Notably, functional enrichment analysis indicated involvement of neuroactive ligand-receptor interactions and hormone transport pathways in the hypothalamus and pituitary, and ciliary motility and spermatogenesis pathways in the testis. PPI network analysis also highlighted many hub genes which involved in spermatogenesis and sperm motility in testis. The localization of an important hub genes TEKT2 was confirmed in spermatogonia within the seminiferous tubules. The study findings provide preliminary understandings into the genetic regulatory mechanisms from HPG axis that govern testicular development and maturation in roosters and offers a foundation for application in the reproductive regulation of breeding roosters in molecular breeding.Keywords: Spermatogenesis, HPG axis, Sexual maturation, Wenchang roosters, DEGs