Lectin binding pattern in the testes of several tetrapode vertebrates.

The glycoconjugates of the testes of four species of vertebrates including amphibians (Bufo calamita), reptiles (Mauremys caspica), birds (Columba livia) and mammals (Mesocricetus auratus) were investigated by means of lectin histochemistry. Spermatogonia of the animals studied were labelled by Con A and WGA. DBA showed a specific affinity for the spermatogonia Aal of the hamster indicating that DBA might be an useful marker for this cell type. The acrosomes of the hamster spermatids were strongly reactive to PNA, SBA and WGA. LTA and UEA-I did not show affinity for the acrosomes of any of the species studied. Lectin reactivity of spermatids and spermatozoa was similar in pigeon and hamster. Sertoli cells were reactive to Con A in all species studied. Affinity to WGA of the spermatozoa tails suggests the addition of the glycoprotein SMA4 in the testis, instead of the epididymis as has been indicated in the mouse. The present results suggest an increase in the glycosylation processes with the differentiation of the spermatogenic lineage being more marked in amphibians and reptiles in the spermatid-spermatozoa step, while in mammals the differences are greater in spermatocyte-spermatid step. The low reactivity to the lectins in the bird studied suggests a low content of glycoconjugates in the testis of this avian species.