Single-cell transcriptome analysis of uniparental embryos reveals parent-of-origin effects on human preimplantation development [RNA-seq]

To investigate the contribution of parental genomes to early embryogenesis, we systematically profiled the single-cell transcriptomes of human biparental and uniparental embryos from one-cell to morula stages. We observed that uniparental embryos exhibit variable and overall less activation patterns of embryonic genome activation (EGA). Comparative transcriptome analysis identified 807 maternally biased expressed genes (MBGs) and 581 paternally biased expressed genes (PBGs) in preimplantation stages. MBGs became obviously appeared at the four-cell stage and contribute to EGA initiation, whereas PBGs preferentially appeared at the eight-cell stage, and possibly affect embryo compaction and trophectoderm specification. Regulatory network analysis revealed DUX4, EGR2 and DUXA as key transcription factors for MBGs expression as well as ZNF263 and KLF3 for PBGs expression. Furthermore, we revealed that the expression of MBGs and PBGs especially PBGs, probably due to DNA methylation differences between the parental genomes. Together, our results provide a valuable resource to understand parental genome activation and may help to dissect parent-of-origin effect on early human development. Overall design: We performed a comprehensively survey of transcriptional activities between biparental and uniparental embryos by single-cell RNA sequencing BI: biparental, AG: androgenetic, PG: parthenogenetic