Single nucleus/cell RNA-seq of the chicken hypothalamic-pituitary-ovarian axis offers new insights into the molecular regulatory mechanisms of ovarian development
Dong Leng, 成都大学药学院, 四川 成都 610106, 中国, Bo Zeng, Tao Wang, Binlong Chen, Diyan Li, Zhuanjian Li, 四川农业大学动物科技学院, 四川 成都 611130, 中国, 西昌学院动物科学学院, 四川 西昌 615000, 中国, 河南农业大学动物科技学院, 河南 郑州 450046, 中国
Abstract
The hypothalamic-pituitary-ovarian (HPO) axis represents a central neuroendocrine network essential for reproductive function. Despite its critical role, the intrinsic heterogeneity within the HPO axis across vertebrates and the complex intercellular interactions remain poorly defined. This study provides the first comprehensive, unbiased, cell type-specific molecular profiling of all three components of the HPO axis in adult Lohmann layers and Liangshan Yanying chickens. Within the hypothalamus, pituitary, and ovary, seven, 12, and 13 distinct cell types were identified, respectively. Results indicated that the pituitary adenylate cyclase activating polypeptide (PACAP), follicle-stimulating hormone (FSH), and prolactin (PRL) signaling pathways may modulate the synthesis and secretion of gonadotropin-releasing hormone (GnRH), FSH, and luteinizing hormone (LH) within the hypothalamus and pituitary. In the ovary, interactions between granulosa cells and oocytes involved the KIT, CD99, LIFR, FN1, and ANGPTL signaling pathways, which collectively regulate follicular maturation. The SEMA4 signaling pathway emerged as a critical mediator across all three tissues of the HPO axis. Additionally, gene expression analysis revealed that relaxin 3 (RLN3), gastrin-releasing peptide (GRP), and cocaine- and amphetamine regulated transcripts (CART, also known as CARTPT) may function as novel endocrine hormones, influencing the HPO axis through autocrine, paracrine, and endocrine pathways. Comparative analyses between Lohmann layers and Liangshan Yanying chickens demonstrated higher expression levels of <italic>GRP</italic>, <italic>RLN3</italic>, <italic>CARTPT</italic>, <italic>LHCGR</italic>, <italic>FSHR</italic>, and <italic>GRPR</italic> in the ovaries of Lohmann layers, potentially contributing to their superior reproductive performance. In conclusion, this study provides a detailed molecular characterization of the HPO axis, offering novel insights into the regulatory mechanisms underlying reproductive biology.