library_construction_protocol: Total RNA was extracted from snap-frozen mouse testis tissues using TRIzol reagent (Beyotime). RNA integrity was assessed via Agilent Bioanalyzer (RIN > 7.0), and RNA purity was verified by A260/A280 ratio (1.8–2.0). RNA sequencing libraries were prepared using the NEBNext® Ultra™ II Directional RNA Library Prep Kit for Illumina® (NEB, USA) according to the manufacturer's protocol. Briefly, mRNA was enriched using oligo-dT beads, fragmented, and reverse transcribed into cDNA. After end repair, adapter ligation, and PCR amplification, libraries were size-selected and quantified using Qubit and Agilent Bioanalyzer.