Fig. 2.

Protein signature of testicular extracellular vesicles. A–C Gene Ontology analysis on cellular component (A), biological process (B), and molecular function (C) of proteins identified on/in testicular EVs. The number next to the bar indicates the number of genes that fall in the category with corresponding P value provided in the blanket. D Heat map of genes encoding the proteins identified in the testicular EVs and their corresponding expression in indicated types of testicular cells according to the average expression level of each cell cluster identified by single-cell RNA sequencing analysis of adult mice testes. Cluster 1—somatic cell-enriched; Cluster 2—Leydig cell-enriched; Cluster 3—post-meiotic germ cell-enriched; Cluster 4—spermatocyte-enriched; Cluster 5—Sertoli cell-enriched; Cluster 6—Spermatogonia-enriched; Cluster 7—macrophage-enriched; Cluster 8—germ cell-enriched; Cluster 9—commonly expressed. E Western blot analysis of candidate protein Basigin (BSG) identified in testicular EVs. EV isolated from the epididymis was used as a control. F Representative immunogold staining images of BSG in testicular EVs. Gold particles are marked by arrowhead. Scale bar: 200 nm. Uncropped blots available in Additional file 7: Fig S8