Ribo-seq analysis elucidates the dynamic translation landscape of yak ovarian tissue across different reproductive stages
Translation, as a crucial link in the transmission of genetic information, plays an indispensable regulatory role in follicular development, ovulation, corpus luteum formation, and degeneration. In order to deeply analyze the molecular mechanisms of reproductive regulation at the translation level, our study focused on the ovarian tissues of yaks at different reproductive stages to analyze gene expression changes using Ribosome profiling and integrating RNA-seq data. Meanwhile, the small open reading frames (sORFs) of ovarian tissue was characterized, and the impact of the translation efficiency of focused genes on their sequence feature was analyzed. The results showed that over 80% of genes in the two groups exhibited inconsistent changes at the transcription and translation levels, indicated that the changes in genes at both levels were complex and not simply synergistic. Upon the pathway enrichment analysis, the signaling pathways involved in these differentially expressed genes were further clarified, such as the estrogen signaling pathway PI3K-Akt, MAPK, calcium signaling pathway and ovarian steroidogenesis. Further research has found that some genes related to ovarian function have inconsistent expression at two levels and exhibit dynamic changes in translation activity, including PALB2, EGR2, BMP7, SOX9, PIK3R2, and WNT2B. Besides, we identified 66 predicted translatable small open reading frames (sORFs) and also explored the impact of upstream ORFs (uORFs) on the translation efficiency of downstream major ORFs (mORFs). This study systematically revealed the gene expression characteristics of ovarian tissues in yaks at different reproductive stages from the perspective of translational level for the first time, providing a new perspective for a deeper understanding of the physiological mechanisms of yak reproduction. Overall design: Construction of ribosomal footprint map of yak ovaries