Characterization of the glycoconjugates of boar testis and epididymis

Lectin histochemistry was used to perform in situ characterization of the g lycoconjugates present in boar testis and epididymis. Thirteen horseradish peroxidase- or digoxigenin-labelled lectins were used in samples obtained f rom healthy fertile boars. The acrosomes of the spermatids were stained int ensely by lectins with affinity for galactose and N-acetyl-galactosamine re sidues, these being soybean, peanut and Ricinus communis agglutinins. Serto li cells were stained selectively by Maackia ammurensis agglutinin. The lam ina propria of seminiferous tubules showed the most intense staining with f ucose-binding lectins. The Golgi area and the apical part of the principal cells of the epididymis were stained intensely with many lectins and their distribution was similar in the three zones of the epididymis. On the basis of lectin affinity, both testis and epididymis appear to have N- and O-lin ked glycoconjugates. Spermatozoa from different epididymal regions showed d ifferent expression of terminal galactose and N-acetyl-galactosamine. Siali c acid (specifically alpha2,3 neuraminic-5 acid) was probably incorporated into spermatozoa along the extratesticular ducts. These findings indicate t hat the development and maturation of boar spermatozoa are accompanied by c hanges in glycoconjugates. As some lectins stain cellular or extracellular compartments specifically, these lectins could be useful markers in histopa thological evaluation of diseases of boar testis and epididymis.