Expression of β-hexosaminidase in the male reproductive system of the lizard, Eutropis carinata. (Reptilia, Squamata) (Schneider, 1801).

Beta-hexosaminidase (Hex) is the major lysosomal enzyme associated with the event of fertilization. In this study, we have analyzed the distribution of Hex in the testis and the epididymis of the lizard, Eutropis carinata by a polyclonal antibody of β-hexosaminidase isoform (Hex A). Presence of Hex in the epididymis was performed by Western blotting. The result reveals that Hex A is present in the epididymal epithelium, lumen as well as spermatozoa. The anatomical distribution of Hex was studied by immunohistochemical localization. The study reveals that Hex is intensely stained in the epithelium of anterior and middle regions of the epididymis, whereas, posterior epididymal epithelium shows moderate staining. In addition, seminiferous epithelium of the testis shows staining for Hex. But lumen of the testis did not show any reaction for Hex. Further, immunohistochemical localization of Hex on the spermatozoa from the testis and different regions of the epididymis revealed that the Hex from the testis did not show any staining; the epididymal epithelium is moderately localized in the spermatozoa of the anterior region and gradually increases in the intensity in the spermatozoa of the posterior region of the epididymis. This indicates that the Hex is released from the epididymal epithelium and binds to the spermatozoa, and in the lumen, it gradually increases from anterior to the posterior region of the epididymis. The result also suggests that Hex A bound to the epididymal spermatozoa originates from the epididymis and not from the testis. The regional difference in the expression of Hex in the epididymis of the lizard, E. carinata, indicates the possible site of secretion of this enzyme.