N4-acetylcytidine (ac4C) modification, present in both long noncoding RNAs (lncRNAs) and messenger RNAs (mRNAs), regulates cell fate decisions, yet its role in female germline stem cell (FGSC) development remains poorly understood. Here, we demonstrate that ac4C modification depletion (in vitro or in vivo) impairs FGSC maintenance by disrupting the EEF1A1-mediated Gm26917-Rpl10 interaction, leading to attenuated protein synthesis. Reduced ac4C levels suppress FGSC viability and proliferation, dysregulate cell cycle progression, and promote differentiation and apoptosis. Integrated acRIP-seq and RNA in situ conformation sequencing (RIC-seq) analyses demonstrate that diminished ac4C modification in lncRNA Gm26917 compromises its stability and weakens its interaction with Rpl10. Strikingly, the reduction of RPL10 is primarily caused by impaired Gm26917-Rpl10 interaction rather than direct ac4C modification. Gm26917 or Rpl10 knockdown disrupts FGSC fate, while ribosome profiling sequencing (Ribo-seq) reveals that Gm26917 depletion significantly reduces mRNA translation efficiency (TE), a defect rescued by Rpl10 overexpression. Furthermore, EEF1A1 disruption diminishes the Gm26917-Rpl10 interaction and decreases mRNA TE. This work establishes that ac4C modification on lncRNAs governs their spatial interactions with mRNAs, elucidates a novel ac4C-Gm26917-EEF1A1-Rpl10 axis in FGSC maintenance, and provides a potential molecular target for modulating germ cell development and fertility.
