Eukaryotic translation elongation factor EEF1G orchestrates the translational program to ensure meiotic progression in transcriptionally silent spermatocytes
During meiotic prophase I, mammalian spermatocytes face a critical challenge that they need to synthesize recombination and synapsis proteins while global transcriptional suppression occurs at leptotene/zygotene stages. Here, we identify a spermatogenic cell highly expressed protein, eukaryotic translation elongation factor 1 gamma (EEF1G), as a master regulator of translational adaptation in mouse spermatocytes. Germ cell-specific Eef1g knockout causes complete male infertility due to the meiotic arrest at the zygotene stage, which is characterized by unresolved DNA double-strand breaks, failed homologous chromosome synapsis, and abolished crossover formation. Mechanistically, EEF1G can interact with ribosome proteins and RNA-binding factors. Ribosome profiling reveals that EEF1G deficiency reduces ribosome processivity, leading to ribosomal stalling and decreased protein production. Consequently, proteomic analyses show a specific decrease of synapsis (e.g., SYCP1/SYCE1) and recombination (e.g., MSH4/TEX11) proteins. This study establishes EEF1G as a critical coordinator of spatial translation in transcriptionally silent spermatocytes, bridging limited mRNA engagement to explosive protein synthesis for meiotic progression. Our work challenges traditional views of meiotic control by highlighting translation elongation, not just as a housekeeping process, but as a stage-specific regulator of germ cell development. Overall design: RNA-seq analyses of the FACS-sorted leptotene and zygotene spermatocytes from 12 days postpartum (dpp). Breifly, cell lysis, mRNA reverse transcription, and cDNA amplification were performed using the Discover-sc WTA Kit V2 (Vazyme, N711). Subsequently, cDNA fragmentation and adapter ligation were carried out with the TruePrep Flexible DNA Library Prep Kit for Illumina (Vazyme, TD504). All procedures were conducted in strict accordance with the manufacturer's protocols. The Smart-seq2 library sequencing was performed by Novogene on Illumina platforms, generating 150 bp paired-end reads.