College of Animal Science, Yangtze University, Jingzhou, China.
College of Animal Science and Technology, Northeast Agricultural University, Harbin, China.
Reprod Domest Anim. 2021 Apr;56(4):642-657. doi: 10.1111/rda.13901. Epub 2021 Feb 2.
The faithful execution of molecular programme underlying oocyte maturation and meiosis is vital to generate competent haploid gametes for efficient mammalian reproduction. However, the organization and principle of molecular circuits and modules for oocyte meiosis remain obscure. Here, we employed the recently developed single-cell RNA-seq technique to profile the transcriptomes of germinal vesicle (GV) and metaphase II (MII) oocytes, aiming to discover the dynamic changes of mRNAs and long non-coding RNAs (lncRNAs) during oocyte in vitro meiotic maturation. During the transition from GV to MII, total number of detected RNAs (mRNAs and lncRNAs) in oocytes decreased. Moreover, 1,807 (602 up- and 1,205 down-regulated) mRNAs and 313 (177 up- and 136 down-regulated) lncRNAs were significantly differentially expressed (DE), i.e., more mRNAs down-regulated, but more lncRNAs up-regulated. During maturation of pig oocytes, mitochondrial mRNAs were actively transcribed, eight of which (ND6, ND5, CYTB, ND1, ND2, COX1, COX2 and COX3) were significantly up-regulated. Both DE mRNAs and targets of DE lncRNAs were enriched in multiple biological and signal pathways potentially associated with oocyte meiosis. Highly abundantly expressed mRNAs (including DNMT1, UHRF2, PCNA, ARMC1, BTG4, ASNS and SEP11) and lncRNAs were also discovered. Weighted gene co-expression network analysis (WGCNA) revealed 20 hub mRNAs in three modules to be important for oocyte meiosis and maturation. Taken together, our findings provide insights and resources for further functional investigation of mRNAs/lncRNAs in in vitro meiotic maturation of pig oocytes.
卵母细胞成熟和减数分裂所涉及的分子程序的忠实执行对于产生有活力的单倍体配子以实现有效的哺乳动物繁殖至关重要。然而，卵母细胞减数分裂的分子回路和模块的组织和原则仍然不清楚。在这里，我们采用最近开发的单细胞 RNA-seq 技术对生发泡（GV）和中期 II（MII）卵母细胞的转录组进行了分析，旨在发现卵母细胞体外减数分裂成熟过程中 mRNA 和长非编码 RNA（lncRNA）的动态变化。在从 GV 到 MII 的转变过程中，卵母细胞中检测到的 RNA（mRNA 和 lncRNA）总数减少。此外，1807 个（602 个上调和 1205 个下调）mRNA 和 313 个（177 个上调和 136 个下调）lncRNA 差异显著表达，即更多的 mRNA 下调，但更多的 lncRNA 上调。在猪卵母细胞成熟过程中，线粒体 mRNA 被积极转录，其中 8 个（ND6、ND5、CYTB、ND1、ND2、COX1、COX2 和 COX3）显著上调。差异表达的 mRNA 和 lncRNA 的靶基因富集在多个与卵母细胞减数分裂相关的生物学和信号通路中。还发现了高度丰富表达的 mRNA（包括 DNMT1、UHRF2、PCNA、ARMC1、BTG4、ASNS 和 SEP11）和 lncRNA。加权基因共表达网络分析（WGCNA）揭示了三个模块中 20 个关键 mRNA 对卵母细胞减数分裂和成熟很重要。总之，我们的研究结果为进一步研究猪卵母细胞体外减数分裂成熟过程中 mRNA/lncRNA 的功能提供了思路和资源。
