library_construction_protocol: For mouse liver, total RNA was extracted using TRIzol™ Reagent (Thermo Fisher Scientific) and PolyA+ RNA was selected twice by Dynabeads™ mRNA Purification Kit (Thermo Fisher Scientific). For zebrafish zygote, mouse MII oocyte and mouse blastocyst samples, the single cells were manually picked and sorted into 12 μl 1X lysis buffer (Takara); NEBNext® rRNA Depletion Kit (NEB) was used to delete DNA and rRNA; RNA samples were sonicated for 2 × 30 seconds, incubated with the anti-m6A antibody from Millipore (ABE572), and precipitated using ethanol. SMART-Seq® Stranded Kit (Takara, Cat. # 634442) was used to prepare RNA sequencing library. Libraries were quantified with KAPA Library Quantification Kits (Roche) and the size distribution was checked using TapeStation D1000 ScreenTape (Agilent Technologies).