Determination of spermatogenesis activity using lectin histochemistry in water monitorlizards (Varanus salvator) harvested from the wild

Lectin is often used to investigate the differentiation and maturation of spermatogenic cells in the testes of several wild animals, facilitating the screening of mature individuals. Therefore, this study aimed to determine spermatogenesis activity using lectin histochemistry in water monitor lizards harvested from the wild. Testes of 43 comprehensively examined water monitor lizards (Varanus salvator) were collected from slaughterhouses in Palembang (Sumatra) and Banten (West Java), Indonesia, with Snout-Vent Length (SVL) ranging from 39 to 96 cm. Additionally, histologic, histomorphometric, Periodic Acid-Schiff (PAS) staining, and lectin histochemistry (Con A, RCA, WGA, PNA, VVA, DBA, UAE-I) observations were performed. The results showed a positive correlation between SVL, morphometry, and histomorphometry at p < 0.05 with Pearson’s Correlation analysis. All specimens presented a spermatogenesis process with different activities among various SVL sizes, where larger animals had higher spermatogenic activity. Moreover, PAS-positive reactions in the testes were mainly observed in the cytoplasmic residues of spermatogenic cells, connective tissue, Leydig cells, and blood vessels. The most dominant reacting lectin bindings were ConA, RCA, and WGA, distributed in nearly all the entire testes, including spermatids and spermatozoa phase. PNA and VVA bindings were localized in Golgi and Cap stage spermatids, while UEA-I and DBA lectins showed no binding reaction. Although larger animals had more spermatogenic cells, the lectin-binding patterns of all animals were similar. The presence of lectin binding of PNA, VVA, and WGA in spermatids and spermatozoa in spermatogenic cells signified that male monitor lizards harvested from the wild were active in the spermatogenic process and able to produce mature spermatozoa.