Zhang Wenhui, Chen Xuejiao, Nie Ruixue, Guo Axiu, Ling Yao, Zhang Bo, Zhang Hao
State Key Laboratory of Animal Biotech Breeding, Beijing Key Laboratory for Animal Genetic Improvement, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.
State Key Laboratory of Animal Biotech Breeding, Beijing Key Laboratory for Animal Genetic Improvement, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.
Food Res Int. 2024 Dec;198:115368. doi: 10.1016/j.foodres.2024.115368. Epub 2024 Nov 17.
Eggs are an important food source for people. Follicle selection and atresia are the two directions of pre-hierarchical follicles that affect egg production in chickens. Granulosa cells (GCs), the vital somatic cells in follicles, determine the fate of follicles. In this study, single-cell RNA sequencing was performed on the GC layers from five follicular stages (small white follicles, atretic small white follicles, small yellow follicles, atretic small yellow follicles, and F6) to map the cellular differentiation trajectories and explore the follicle fate-determining genes. The results showed that GCs were genetically heterogeneous and could be divided into four subtypes, and the presence of GCs-Ⅲ with a steroid-producing capacity in unselected small follicles is a novel finding that differs from conventional wisdom. In addition, degenerated GCs were annotated for the first time, and GC degeneration was found to be significantly related to lipid metabolism disorders. Many candidate switch genes had been marked out, among which the overexpression of transforming growth factor-beta 2 (TGFB2) and insulin like growth factor binding protein 5 (IGFBP5) could inhibit the proliferation and differentiation of GCs and induce their degeneration. This study provided new insights into the regulatory mechanisms of follicle selection and atresia, which have significant value for improving egg production and prolonging the laying period of laying hens.
鸡蛋是人类重要的食物来源。卵泡选择和闭锁是影响鸡产蛋量的前等级卵泡的两个发展方向。颗粒细胞（GCs）是卵泡中至关重要的体细胞，决定着卵泡的命运。在本研究中，对五个卵泡阶段（小白卵泡、闭锁小白卵泡、小黄卵泡、闭锁小黄卵泡和F6）的颗粒细胞层进行了单细胞RNA测序，以绘制细胞分化轨迹并探索卵泡命运决定基因。结果表明，颗粒细胞在基因上具有异质性，可分为四种亚型，未被选择的小卵泡中具有类固醇生成能力的GCs-Ⅲ的存在是一项与传统认知不同的新发现。此外，首次对退化的颗粒细胞进行了注释，发现颗粒细胞退化与脂质代谢紊乱显著相关。已筛选出许多候选转换基因，其中转化生长因子-β2（TGFB2）和胰岛素样生长因子结合蛋白5（IGFBP5）的过表达可抑制颗粒细胞的增殖和分化并诱导其退化。本研究为卵泡选择和闭锁的调控机制提供了新见解，对提高蛋鸡产蛋量和延长产蛋期具有重要价值。
