Variação sazonal da proteômica do fluido folicular em cavalos.
ovary; follicle; seasonality; proteomics; mares, horses
Proteomic studies of follicular fluid (FF) exist for several species, including the horse; however, the seasonal influence on FF proteome has not been explored in livestock. The application of large-scale proteomic analyses of FF in the horse has the potential to identify seasonal variations of proteins involved in follicle and oocyte growth. This study (i) profiles the proteomes of equine FF collected from dominant growing follicles during the spring anovulatory season (SAN), and spring (SOV), summer (SU), and fall (FO) ovulatory seasons; and (ii) identifies season-dependent regulatory networks and associated key proteins. Regardless of season, a total of 90 proteins were identified in FF, corresponding to 63, 72, 69, and 78 proteins detected in the SAN, SOV, SU, and FO seasons, respectively. Fifty-two proteins were common to all seasons, a total of 13 were unique to either season, and 25 were shared between two seasons or more. Protein-to-protein interaction (PPI) analysis indicated the likely critical roles of plasminogen in the SAN season, the prothrombin/plasminogen combination in SU, and plasminogen/complement C3 in both SOV and FO seasons. The apolipoprotein A1 appeared crucial in all seasons. The present findings show that FF proteome of SU differs from other seasons, with FF having high fluidity. Finally, the balance between the FF contents in prothrombin, plasminogen, and coagulation factor XII proteins favoring FF fluidity may be crucial at the peak of the ovulatory season (SU) and may explain the reported lower incidence of hemorrhagic anovulatory follicles during the SU season.