Herbivore Laboratory, College of Animal Science, South China Agricultural University, Guangzhou, 510642, China.
National Joint Engineering Research Center, South China Agricultural University, Guangzhou, 510642, China.
BMC Genomics. 2024 Sep 28;25(1):893. doi: 10.1186/s12864-024-10834-w.
Circular RNAs (circRNAs) play important regulatory roles in a variety of biological processes in mammals. Multiple birth-traits in goats are affected by several factors, but the expression and function of circRNAs in follicular development of goats are not clear. In this study, we aimed to investigate the possible regulatory mechanisms of circRNA and collected five groups of large follicles (Follicle diameter > 6 mm) and small follicles (1 mm < Follicle diameter < 3 mm) from Leizhou goats in estrus for RNA sequencing.
RNA sequencing showed that 152 circRNAs were differentially expressed in small and large follicles. Among them, 101 circRNAs were up-regulated in large follicles and 51 circRNAs were up-regulated in small follicles. GO and KEGG enrichment analyses showed that parental genes of the differential circRNAs were significantly enriched in important pathways, such as ovarian steroidogenesis, GnRH signaling pathway, animal autophagy and oxytocin signalling pathway. BioSignal analysis revealed that 152 differentially expressed circRNAs could target 91 differential miRNAs including miR-101 family (chi-miR-101-3p, chi-miR-101-5p), miR-202 family (chi-miR-202-5p, chi-miR-202-3p),60 circRNAs with translation potential. Based on the predicted sequencing results, the ceRNA networks chicirc_008762/chi-miR-338-3p/ARHGAP18 and chicirc_040444/chi-miR-338-3p/STAR were constructed in this study. Importantly, the new gene circCFAP20DC was first discovered in goats. The EDU assay and flow cytometry results indicated that circCFAP20DC enhanced the proliferation of follicular granulosa cells(GCs). Real-time quantitative PCR and western blotting assays showed that circCFAP20DC activated the Retinoblastoma(RB) pathway and promoted the progression of granulosa cells from G1 to S phase.
Differential circRNAs in goat size follicles may have important biological functions for follicular development. The novel gene circCFAP20DC activates the RB pathway, promoting the progression of GCs from G1 to S phase. This, in turn, enhances the proliferation of follicular GCs in goats.
环状 RNA（circRNA）在哺乳动物的多种生物学过程中发挥着重要的调控作用。山羊的多种繁殖性状受到多种因素的影响，但circRNA 在山羊卵泡发育中的表达和功能尚不清楚。本研究旨在探讨 circRNA 的可能调控机制，收集雷州山羊发情期大卵泡（卵泡直径>6mm）和小卵泡（1mm<卵泡直径<3mm）5 组进行 RNA 测序。
RNA 测序显示，小卵泡和大卵泡中差异表达的 circRNA 有 152 个。其中，大卵泡中上调的 circRNA 有 101 个，小卵泡中上调的 circRNA 有 51 个。GO 和 KEGG 富集分析表明，差异 circRNA 的亲本基因显著富集在卵巢甾体生成、GnRH 信号通路、动物自噬和催产素信号通路等重要通路中。BioSignal 分析显示，152 个差异表达的 circRNA 可以靶向包括 miR-101 家族（chi-miR-101-3p、chi-miR-101-5p）、miR-202 家族（chi-miR-202-5p、chi-miR-202-3p）在内的 91 个差异 miRNA。60 个具有翻译潜力的 circRNA。基于预测的测序结果，本研究构建了 ceRNA 网络 chicirc_008762/chi-miR-338-3p/ARHGAP18 和 chicirc_040444/chi-miR-338-3p/STAR。重要的是，首次在山羊中发现了新基因 circCFAP20DC。EDU 检测和流式细胞术结果表明，circCFAP20DC 增强了卵泡颗粒细胞（GCs）的增殖。实时定量 PCR 和 Western blot 检测显示，circCFAP20DC 激活了视网膜母细胞瘤（RB）通路，促进了颗粒细胞从 G1 期向 S 期的进展。
山羊大小卵泡中的差异 circRNA 可能对卵泡发育具有重要的生物学功能。新基因 circCFAP20DC 激活了 RB 通路，促进了 GCs 从 G1 期向 S 期的进展。这反过来又增强了山羊卵泡颗粒细胞的增殖。
