Molecular characteristics of early-stage female germ cells revealed by RNA sequencing of low-input cells and analysis of genome-wide DNA methylation

High-throughput stage-specific transcriptomics provides an unbiased approach for understanding the process of cell development. Here, we report transcriptome analysis of primordial germ cell, female germline stem cell (FGSC), germinal vesicle and mature oocyte by performing RNA sequencing of freshly isolated cells in mice. As expected, these stages and gene-expression profiles are consistent with developmental timing. Analysis of genome-wide DNA methylation during female germline development was used for confirmation. By pathway analysis and blocking experiments, we demonstrate PI3K-AKT pathway is critical for FGSC maintenance. We also identify functional modules with hub genes and lncRNAs, which represent candidates for regulating FGSC self-renewal and differentiation. Remarkably, we note alternative splicing patterns change dramatically during female germline development, with the highest occurring in FGSCs. These findings are invaluable resource for dissecting the molecular pathways and processes into oogenesis and will be wider applications for other types of stem cell research.