Yu Shigang, Shen Xuemei, Wang Gang, Liao Juan, Chen Jia
Engineering Research Center of Sichuan Province Higher School of Local Chicken Breeds Industrialization in Southern Sichuan, College of Life Science, Leshan Normal University, Leshan 614000, China.
Engineering Research Center of Sichuan Province Higher School of Local Chicken Breeds Industrialization in Southern Sichuan, College of Life Science, Leshan Normal University, Leshan 614000, China.
Poult Sci. 2025 Jun 11;104(9):105430. doi: 10.1016/j.psj.2025.105430.
Functional differentiation of the granulosa cell (GC) layer plays an essential role in follicular development and oocyte maturation in birds. However, despite the importance of GCs, heterogeneity within the granulosa layer across poultry species remains poorly defined and functional transcriptomic signatures across distinct cellular subpopulations are lacking. In this study, single-cell RNA sequencing was used to identify GC types, uncover heterogeneity, and construct the developmental trajectories of chicken GCs at two developmental stages: the hierarchical follicle (HF)-GC and prehierarchical follicle (PHF)-GC stages. The following four GC types were identified: rapid growth, early, luteal, and primitive GCs. We found significant differences in the abundance of these different cell types at the HF-GC and PHF-GC stages. We also identified four potential differentiation trajectories for GCs during follicular development. The four distinct developmental trajectories may elucidate that the dynamic interplay and transition among these four GC types are pivotal in determining the fate of the follicle. A single-cell regulatory network inference and clustering analysis was performed to identify specifically expressed transcription factors in the different GC types. These transcription factors may have key regulatory roles in follicular development. Furthermore, we identified genes that were differentially expressed in HF-GCs and PHF-GCs. In total, 1,049 differentially expressed genes were identified in the two groups, including 379 upregulated and 670 downregulated genes. Finally, we identified several genes that may play important roles in follicle selection and development in chicken, including CDK2, CCND1, CCND2, BCL2, FOXO1, AMH, WT1, STAR, CYP11A1, HSD11B2, CYP51A1, and ESR1. These findings enhance our understanding of the cell biology of the GC layer in ovarian follicles and provide a basis for future studies of the relevant molecular regulatory mechanisms.
颗粒细胞（GC）层的功能分化在禽类卵泡发育和卵母细胞成熟过程中起着至关重要的作用。然而，尽管颗粒细胞很重要，但不同家禽物种颗粒层内的异质性仍定义不清，且缺乏不同细胞亚群的功能转录组特征。在本研究中，利用单细胞RNA测序来鉴定鸡颗粒细胞的类型，揭示其异质性，并构建两个发育阶段（分级卵泡（HF）-GC阶段和分级前卵泡（PHF）-GC阶段）鸡颗粒细胞的发育轨迹。鉴定出了以下四种颗粒细胞类型：快速生长型、早期型、黄体型和原始型颗粒细胞。我们发现这些不同细胞类型在HF-GC和PHF-GC阶段的丰度存在显著差异。我们还确定了卵泡发育过程中颗粒细胞的四条潜在分化轨迹。这四条不同的发育轨迹可能说明这四种颗粒细胞类型之间的动态相互作用和转变对于决定卵泡的命运至关重要。进行了单细胞调控网络推断和聚类分析，以鉴定不同颗粒细胞类型中特异性表达的转录因子。这些转录因子可能在卵泡发育中起关键调控作用。此外，我们鉴定了在HF-GC和PHF-GC中差异表达的基因。两组中共鉴定出1049个差异表达基因，包括379个上调基因和670个下调基因。最后，我们鉴定了几个可能在鸡卵泡选择和发育中起重要作用的基因，包括CDK2、CCND1、CCND2、BCL2、FOXO1、AMH、WT1、STAR、CYP11A1、HSD11B2、CYP51A1和ESR1。这些发现加深了我们对卵巢卵泡颗粒层细胞生物学的理解，并为未来相关分子调控机制的研究提供了基础。
