NAT10-mediated mRNA <i>N</i> ⁴ -acetylation is essential for the translational regulation during oocyte meiotic maturation in mice

The precise translational regulation of maternal messenger RNAs (mRNAs) drives mammalian oocyte maturation. However, the function and mechanism of posttranscriptional chemical modifications, especially the newly identified <i>N</i>⁴-acetylcytidine (ac⁴C) modification catalyzed by <i>N</i>-acetyltransferase 10 (NAT10), are unknown. In this study, we developed a low-input ac⁴C sequencing technology, ac⁴C LACE-seq, and mapped 8241 ac⁴C peaks at the whole-transcriptome level using 50 mouse oocytes at the germinal vesicle stage. Oocyte-specific <i>Nat10</i> knockout wiped out ac⁴C signals in oocytes and caused severe defects in meiotic maturation and female infertility. Mechanically, <i>Nat10</i> deletion led to a failure of ac⁴C deposition on mRNAs encoding key maternal factors, which regulate transcriptome stability and maternal-to-zygotic transition. <i>Nat10</i>-deleted oocytes showed decreased mRNA translation efficiency due to the direct inhibition of ac⁴C sites on specific transcripts during meiotic maturation. In summary, we developed a low-input, high-sensitivity mRNA ac⁴C profiling approach and highlighted the important physiological function of ac⁴C in the precise regulation of oocyte meiotic maturation by enhancing translation efficiency.