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

Abstract

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.

Epididymis of the Lizard <i>Eutropis carinata</i>: A Light Microscopic and Ultrastructural Seasonal Study

“…The studies further indicated that Hex is released from the epididymal epithelium and binds to the spermatozoa and, in the lumen, it gradually increases from the anterior to the posterior region of the epididymis. The latter report also suggested that Hex A which binds to the epididymal spermatozoa originates from the epididymis 58 . The above studies on the epididymis of E. carinata implicate that the biochemical complexity of sperm activation observed is consistent with those reported in mammals.…”

“…Beta-hexosaminidase (Hex) is the major lysosomal enzyme associated with the event of fertilization. The presence of Hex in the epididymis of the lizard E. carinata has been demonstrated 58 . The studies further indicated that Hex is released from the epididymal epithelium and binds to the spermatozoa and, in the lumen, it gradually increases from the anterior to the posterior region of the epididymis.…”

“…During the annual reproductive cycle, the epididymis of the lizard E. carinata undergoes dramatic changes, both morphologically and biochemically, that occur in a well-organized sequence. Enzymes, such as acid phosphatase, alkaline phosphatase, and α-glucosidase, are highly sensitive to seasonal changes and their activity parallels the production of epididymal proteins 29,[56][57][58] . Beta-hexosaminidase (Hex) is the major lysosomal enzyme associated with the event of fertilization.…”

Chronic stress affects tyrosine phosphorylated protein expression and secretion of male rat epididymis

“…Based on literatures, we proposed that a 65 kDa protein may be a lysosomal enzyme called β‐hexosaminidase secreted from epithelial cells of epididymis to bind sperm surface (Andrea et al., 2001). This enzyme has been further known to be responsible for early process of gamete interaction (Medini et al., 2018; Miranda et al., 2000). Moreover, the 70 and 73‐kDa proteins observed to be overexpressed in epididymal fluid of CS could belong to clusterin and semenogelin, respectively, as previously reported (Andrea et al., 2001; Sylvester et al., 1991).…”