Pluto Bioinformatics

GSE109555: Reconstituting the transcriptome and DNA methylome landscapes of human implantation

Bulk RNA sequencing

Implantation is a milestone event during mammalian embryogenesis. Implantation failure is a nonnegligible cause of human early pregnancy loss. Due to the extreme difficulty of obtaining in vivo human early post-implantation embryos, it remains elusive how the gene regulatory network and epigenetic mechanisms control human embryo implantation. Here, combining an in vitro culture system for human post-implantation development and single-cell omics sequencing technologies, over 8,000 individual cells from 65 human peri-implantation embryos were systematically analyzed. Unsupervised dimensionality reduction and clustering algorithm of the transcriptome data show stepwise implantation routes for the epiblast (EPI), primitive endoderm (PE), and trophectoderm (TE) lineages, suggesting robust preparation for the proper establishment of a mother-to-offspring connection during implantation. Female embryos showed initiation of random X chromosome inactivation based on analysis of parental allele-specific expression of X chromosome-linked genes during implantation. Surprisingly, by the single-cell Trio-Seq (scTrio-Seq) analysis, the genome re-methylation of PE lineage was shown to be much slower than those of both EPI and TE lineages during implantation process, indicating distinct DNA methylome re-establishment features between EPI and PE although both of which were derived from inner cell mass (ICM). Collectively, our work paves the way for understanding the complex molecular mechanisms that regulate human embryo implantation, offering new insights and future efforts in early embryonic development and reproductive medicine. SOURCE: Rui WANG (fish_cat_wr@sina.cn) - Fuchou Tang Peking University