First isolation and characterization of caprine oviduct fluid extracellular vesicles

Oviduct fluid extracellular vesicles (oEV) are essential for periconceptional events. The presence of EV has already been identified in the oviduct fluid (OF) from mammalian species, except in caprine. Therefore, this study aimed to isolate and characterize the caprine oEV (coEV). Initially, in Experiment 1, coEV were isolated from the OF of either each animal individually or from a pool of three animals. In experiment 2, coEV were isolated during the follicular or luteal phases of the estrous cycle. The coEV were characterized by size distribution, polydispersity index (PDI), and zeta potential using dynamic light scattering (DLS) analysis, as well as, by transmission electron microscopy (TEM) and dot blotting (DB). Our results indicated that the physicochemical characteristics of the coEV were similar (P > 0.05), regardless of the isolation method (individual or pool). However, coEV collected during the luteal phase were larger (P < 0.05) than those during the follicular phase. The TEM showed spherical and cup-shaped particles, characteristic of exosomes. The DB revealed the presence of exosomal proteins involved in the biogenesis of coEV. In conclusion, it is possible to isolate and characterize coEV from a single caprine female and the estrous cycle phase influences the vesicles average size and PDI.