The RNA m⁶A landscape during human oocyte-to-embryo transition

Area of Science:

• Epigenetics
• Developmental Biology
• Molecular Biology

Background:

• RNA N⁶-methyladenosine (m⁶A) is a key epigenetic modification regulating cellular processes.
• The dynamic m⁶A landscape in human preimplantation embryos is largely unknown.

Purpose of the Study:

• To characterize the RNA m⁶A landscape in single human oocytes and early embryos.
• To investigate the functional implications of m⁶A modifications during human embryogenesis.

Main Methods:

• Single-cell RNA sequencing
• m⁶A profiling
• Comparative analysis with mouse models
• Gene expression analysis
• miRNA target prediction

Main Results:

• First comprehensive m⁶A landscape of human oocytes and early embryos.
• Divergent roles of m⁶A-modified (gene transcription) versus unmodified (metabolism) genes during zygotic genome activation.
• m⁶A targets maternal mRNAs for decay and miRNA interaction.
• m⁶A enhances translation of constantly expressed genes.
• Enrichment of m⁶A on stage-specific retrotransposons, sensitive to m⁶A inhibition.

Conclusions:

• m⁶A plays a significant regulatory role in human early embryonic development.
• m⁶A influences gene expression, mRNA decay, translation, and retrotransposon activity.
• This study provides a valuable resource for understanding m⁶A dynamics in embryogenesis.