Immunohistochemical localization of galectin-3 in boar testis and epididymis

The presence and distribution of galectin-3, a beta-galactoside-binding protein, in boar testis and epididymis was studied. Western blot analysis detected galectin-3 in boar testis and epididymis. In particular, intense galectin-3 immunoreaction was seen in the tail of the epididymis, while it was moderate in the head and body. Galectin-3 immunolabelling was detected in the connective tissues of the testis. In the testis, galectin-3 was detected in some cells (presumably peritubular myoid cells), but not in Leydig cells or the cells of the seminiferous tubules. In the epididymis, the galectin-3 immunoreactivity in the connective tissues was the same as in the testis. Intense galectin-3 immunolabelling was seen in the covering epithelium of the epididymis tail, but in very few cells in the head and body. We postulate that galectin-3, immunodetected here in the connective tissues in the male reproductive organs, serves as an extracellular matrix. Furthermore, we postulate that intracellular galectin-3 in the epithelium of the epididymis tail plays a role in either the maintenance of the epithelium or as a source of galectin-3 in the seminal fluid; here it may play a role in sperm activation in the boar reproductive system.