Comprehensive transcriptomic analysis of the hypothalamic-pituitary-ovarian axis reveals the role of Aurora Kinase B in regulating follicular granulosa cell development and steroid hormone synthesis in Wuding chickens.

Wuding chicken, an indigenous avian breed native to China, is known for its high-quality meat and eggs. However, it has a low egg production rate, poor reproductive traits, and strong broody behavior. Ovarian follicle development is essential for egg production and reproduction, being regulated by the hypothalamus-pituitary-ovary (HPO) axis. Despite its significance, the molecular mechanism of this process in Wuding chicken is still unclear. In this study, the expression profiles of the hypothalamus, pituitary and ovary of Wuding chickens during laying and brooding periods were sequenced and analyzed. A total of 590, 423 and 5371 differentially expressed genes were identified in these three tissues, respectively. We selected genes enriched in reproduction-related signaling pathways to construct a protein-protein interaction network. The network showed that there were 17 genes that were hub genes, including CDK1, CCNB1, CDK2, PLK1, CDC20, AURKB, MAD2L1, BUB1, CCNB3, FZR1, BUB1B, CDC6, CCNA1, MAPK11, MCM3, ESPL1 and CHEK1. After isolating and identifying follicular granulosa cells (GCs), we assessed the function of the hub Aurora Kinase B (AURKB) gene within the network. Overexpression and knockdown experiments confirmed that AURKB promoted the synthesis of steroid hormones, estradiol and progesterone, in GCs by regulating the expression of STAR, CYP19A1, HSD3B1, and PTGS2 genes. In addition, AURKB enhanced GC proliferation while inhibiting GC senescence and apoptosis. These findings indicate that AURKB plays a crucial role in follicular development in Wuding chickens, providing valuable insights into their reproductive biology and laying the foundation for improving their brooding characteristics.