N-acetyltransferase 10-mediated mRNA N4-acetylation is Essential for the Translational Regulation During Oocyte Meiotic Maturation in Mice

Mammalian oocyte maturation is driven by the strict translational regulation of maternal mRNAs stored in the cytoplasm. However, the function and mechanism of post-transcriptional chemical modifications, especially the newly identified N4-acetylcytidine (ac ⁴ C) modification catalyzed by N-acetyltransferase 10 (NAT10), are unknown. In this study, we developed a low-input ac ⁴ C sequencing technology, ac ⁴ C LACE-seq, and mapped 8241 ac ⁴ C peaks at the whole-transcriptome level using 50 mouse oocytes at the germinal vesicle stage. We profiled the mRNA landscapes of NAT10-interactions and ac ⁴ C modifications. The NAT10-interacted and ac ⁴ C-modified transcripts are associated with high translation efficiency in oocytes. Oocyte-specific Nat10 knockout wiped out ac ⁴ C signals in oocytes and caused severe defects in meiotic maturation and female infertility. ac ⁴ C LACE-seq results indicated that Nat10 deletion led to a failure of ac ⁴ C deposition on mRNAs encoding key maternal factors, such as MSY2, ZAR1, BTG4, and cyclin B1, which regulate transcriptome stability and maternal-to-zygotic transition. Nat10 -deleted oocytes showed decreased mRNA translation efficiency during meiotic maturation, partially due to the direct inhibition of ac ⁴ C sites on specific transcripts. In summary, we developed a low-input, high-sensitivity mRNA ac ⁴ C profiling approach and highlighted the important physiological function of ac ⁴ C in the precise regulation of oocyte meiotic maturation by enhancing translation efficiency.