Lipidomic and transcriptomic characteristics of boar seminal plasma extracellular vesicles associated with sperm motility

Seminal plasma extracellular vesicles (SPEVs) play an important role in regulating sperm motility by delivering various cargoes, such as miRNAs, mRNAs, proteins and metabolites. However, information on the lipid compositions of SPEVs and their roles in semen quality is limited. Here, we performed high-throughput transcriptomic and lipidomic analysis on SPEVs isolated from 20 boars with high or low sperm motility. Then, we evaluated the lipid composition and gene expression characteristics of SPEVs and identified the specific lipids and genes related to sperm motility. As a result, a total of 26 lipid classes were identified in SPEVs, and five subclasses, CerG2, CerG3, LPE, LPS and TG, were significantly different in boars with high and low sperm motility. In addition, 195 important lipids and 334 important genes were identified by weighted gene coexpression analysis (WGCNA) and differential expression analysis. We observed that several important genes and lipids in SPEVs potentially influence sperm motility via glycerophospholipid metabolism, glycerolipid metabolism, the sphingolipid signaling pathway and the ferroptosis pathway. Furthermore, we found a significant correlation between the content of 22 lipids and the expression levels of 67 genes (|cor| > 0.8, P < 0.05). Moreover, we observed that three important gene-lipid linkages (CerG1 (d22:0/24:0) - RCAN3, Cer (d18:1/24:0) - SCFD2 and CerG1 (d18:0/24:1) - SCFD2) were strongly correlated with sperm motility. Based on the results, some genes and lipids in SPEVs may play important roles in sperm motility by interacting with sperm through important pathways.