Distribution of lectin binding in the testes of the musk shrew, Suncus murinus

Distribution of lectin binding in the testis of the musk shrew, Suncus murinus, was investigated by light and transmission electron microscopy. Not only spermatogenic cells but also Sertoli cells bound some lectins. Canavalia ensiformis agglutinin (Con A) and wheat germ agglutinin (WGA, Triticum vulgaris), indicating the presence of D-mannose and N-acetyl-D-glucosamine respectively, showed an intense reaction in the acrosomal region of early to late spermatids. Ricinus communis agglutinin I (RCA-I), peanut agglutinin (PNA, Arachis hypogaea), Bauhinia purpurea agglutinin (BPA), soybean agglutinin (SBA, Glycine max), revealing the presence of D-galactose and/or N-acetyl-D-galactosamine, bound to the acrosomal region from Golgi to acrosome-phase spermatids and abruptly decreased in intensity in maturation-phase spermatids. GS-II, indicating the presence of N-acetyl-D-glucosamine, gave an intense reaction only in the acrosome of acrosome-phase spermatids. These findings demonstrate that the appearance/disappearance of some glycoconjugates in the spermatid acrosome occurs in the musk shrew during acrosomal formation. Additionally, RCA-I, PNA and BPA revealed a strong reaction in the cytoplasm of Sertoli cells. The reaction that was observed in the intramembranous region of Sertoli cell cytoplasm at the electron microscope level appeared from stages VIII to XIII but not from stages I to VII. This finding suggests that glycoconjugates containing D-galactose may change stage-dependently in the musk shrew Sertoli cell.