Unveiling regulatory network of porcine oocyte IVM using integrated multi-omics

Abstract

In vitro matured oocytes are an indispensable biological material for reproductive biology, as well as agricultural and biomedical research. However, the mechanisms underlying the oocyte maturation in vitro are not yet fully elucidated. Providing a systematic and comprehensive explanation of the complex regulatory network of oocyte maturation is challenging when relying on a single omics data. Therefore, we conducted transcriptomic, proteomic and metabolomic analyses to investigate the mechanism underlying the porcine oocytes maturation. The results revealed a total of 2624 differentially expressed genes, 127 proteins and 17 and metabolites. Among these, 759 genes were uniquely expressed in GV-stage oocytes and 336 genes were exclusively expressed in MII-stage oocytes. Genes highly expressed at GV-stage were primarily involved in cytoplasmic-related processes, whereas those at MII-stage were associated with nuclear meiotic division. A total of 22 differentially expressed proteins (DEPs) were upregulated, while 105 were downregulated in the MII-stage oocyte compared to GV-stage oocytes. Furthermore, 65 proteins including RAB22A, ITPRID2, KIF14, LAMB1, BTG4 were predominantly expressed at MII-stage oocytes. Similarly, six differential metabolites (DMs) were upregulated, while eleven were downregulated in the MII-stage oocytes. Integrated transcriptome, proteome, and metabolome analyses revealed that these differentially expressed components were enriched in glutathione metabolism pathway, highlighting the regulatory roles of DNA methylation, histone acetylation, nuclear transport, translational control, and post-translational modification in oocyte maturation. In conclusion, this multi-omics approach identified key regulators of porcine oocyte maturation in vitro, providing some theoretical basis for understanding the regulatory mechanisms involved.