The chromatin accessibility landscape of mouse oocytes during configuration transition (RNA-Seq)

The transition of chromatin configuration in mammalian oocytes from a non-surrounded nucleolus (NSN) to a surrounded nucleolus (SN) is critical for acquiring the developmental competence. However, the genomic and epigenomic features underlying this process remain poorly understood. In the present study, we first establish the chromatin accessibility landscape of mouse oocyte from NSN to SN stage. Through the integrative analysis of multi-omics, we find that establishment of DNA methylation in oocytes is independent on the dynamics of chromatin accessibility. In contrast, histone H3K4me3 status is closely associated with the dynamics of accessible-regions during configuration transition. Furthermore, by focusing on the actively transcribed genes in NSN and SN oocytes, we discover that chromatin accessibility coupled with histone methylation (H3K4me3 and H3K27me3) participates in the transcriptional control during phase transition. In sum, our data serve as a broad resource for probing configuration transition in oocytes, and provide the potential evidence to elucidate the mechanism determining chromatin dynamics and oocyte quality. Transcriptome profiling by high throughput sequencing哺乳动物卵母细胞的染色质构型从非环绕核仁（non-surrounded nucleolus, NSN）向环绕核仁（surrounded nucleolus, SN）的转变，是其获得发育能力的关键过程。然而，该过程背后的基因组与表观基因组特征仍尚未被充分阐明。本研究首先构建了小鼠卵母细胞从NSN阶段至SN阶段的染色质可及性图谱。通过多组学整合分析，我们发现卵母细胞中的DNA甲基化建立过程并不依赖于染色质可及性的动态变化。与之相反，组蛋白H3K4me3（histone H3K4me3）的修饰状态与该构型转变过程中开放染色质区域的动态变化密切相关。此外，通过聚焦NSN与SN卵母细胞中的活跃转录基因，我们发现染色质可及性与组蛋白甲基化（H3K4me3及H3K27me3）共同参与了该阶段转变过程中的转录调控。综上，本研究数据可为探究卵母细胞染色质构型转变提供丰富的研究资源，并为阐明决定染色质动态变化与卵母细胞质量的潜在机制提供了依据。基于高通量测序的转录组分析