Partial characterization of antigenic sperm proteins in foxes (Vulpes vulpes)

Abstract

The aim of this work was to identify antigenic proteins on fox spermatozoa. Fox spermatozoa proteins were injected into 3 female rabbits and into 3 male and 3 female foxes. In rabbits, a rapid humoral response was observed. Using rabbit sera for Western blotting, 23 fox sperm protein bands were recognized between 10 and 110 kd. In foxes, the time course of antibody response was studied in the same manner. The number of recognized bands was maximal on day 75 for 2 foxes, on day 90 for 3 foxes, and on day 120 for 1 fox. Western blot patterns varied from one fox to another. On the whole, 25 protein bands between 10 and 110 kd were recognized. Using fluorescein isothiocyanate (FITC) labeling on fox spermatozoa with rabbit and fox sera, we showed that several antigens recognized by the antisera were located at or near the surface of the spermatozoa. By two-dimensional electrophoresis and gel-purification, we have selected 6 highly antigenic proteins with molecular weights of 11.4, 14.7, 16.4, 16.4, 16.8, and 16.9 kd, and isoelectric points of 6.0, 6.0, 6.2, 5.5, 5.3, and 5.8, respectively, and one antigenic protein at 97 kd with an isoelectric point of 4.3 to 4.6. The results of this study can be used to characterize these 7 antigens selected more precisely by microsequencing or mass spectrometry.