Ge Ting, Wen Yifan, Li Bo, Huang Xiaoyu, Jiang Shaohua, Zhang Enping
Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, 712100, China.
J Anim Sci Biotechnol. 2023 Nov 14;14(1):144. doi: 10.1186/s40104-023-00941-1.
In the modern sheep production systems, the reproductive performance of ewes determines the economic profitability of farming. Revealing the genetic mechanisms underlying differences in the litter size is important for the selection and breeding of highly prolific ewes. Hu sheep, a high-quality Chinese sheep breed, is known for its high fecundity and is often used as a model to study prolificacy traits. In the current study, animals were divided into two groups according to their delivery rates in three consecutive lambing seasons (namely, the high and low reproductive groups with ≥ 3 lambs and one lamb per season, n = 3, respectively). The ewes were slaughtered within 12 h of estrus, and unilateral ovarian tissues were collected and analyzed by 10× Genomics single-cell RNA sequencing.
A total of 5 types of somatic cells were identified and corresponding expression profiles were mapped in the ovaries of each group. Noticeably, the differences in the ovary somatic cell expression profiles between the high and low reproductive groups were mainly clustered in the granulosa cells. Furthermore, four granulosa cell subtypes were identified. GeneSwitches analysis revealed that the abundance of JPH1 expression and the reduction of LOC101112291 expression could lead to different evolutionary directions of the granulosa cells. Additionally, the expression levels of FTH1 and FTL in mural granulosa cells of the highly reproductive group were significantly higher. These genes inhibit necroptosis and ferroptosis of mural granulosa cells, which helps prevent follicular atresia.
This study provides insights into the molecular mechanisms underlying the high fecundity of Hu sheep. The differences in gene expression profiles, particularly in the granulosa cells, suggest that these cells play a critical role in female prolificacy. The findings also highlight the importance of genes such as JPH1, LOC101112291, FTH1, and FTL in regulating granulosa cell function and follicular development.
在现代绵羊生产系统中，母羊的繁殖性能决定了养殖的经济效益。揭示产羔数差异背后的遗传机制对于高产母羊的选育至关重要。湖羊是一种优质的中国绵羊品种，以其高繁殖力而闻名，常被用作研究繁殖性状的模型。在本研究中，根据动物在连续三个产羔季节的产羔率将其分为两组（即高产和低产繁殖组，每组每季产羔≥3只和1只，n分别为3只）。在发情后12小时内屠宰母羊，收集单侧卵巢组织并通过10×基因组学单细胞RNA测序进行分析。
共鉴定出5种体细胞类型，并绘制了每组卵巢中的相应表达谱。值得注意的是，高产和低产繁殖组之间卵巢体细胞表达谱的差异主要集中在颗粒细胞中。此外，还鉴定出四种颗粒细胞亚型。基因开关分析表明，JPH1表达丰度的增加和LOC101112291表达的降低可能导致颗粒细胞不同的进化方向。此外，高产繁殖组壁颗粒细胞中FTH1和FTL的表达水平显著更高。这些基因抑制壁颗粒细胞的坏死性凋亡和铁死亡，有助于防止卵泡闭锁。
本研究深入探讨了湖羊高繁殖力的分子机制。基因表达谱的差异，特别是在颗粒细胞中的差异，表明这些细胞在雌性繁殖力中起关键作用。研究结果还突出了JPH1、LOC101112291、FTH1和FTL等基因在调节颗粒细胞功能和卵泡发育中的重要性。
