Testicular apoptosis in feral Clarias gariepinus using TUNEL and cleaved caspase-3 immunohistochemistry

• Published in: Ecotoxicology and environmental safety Vol. 71; no. 1; pp. 41 - 46
• Main Authors: McClusky, Leon M., Barnhoorn, Irene E.J., van Dyk, Jacobus C., Bornman, Maria S.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01.09.2008
• Subjects: Animals; Apoptosis; Apoptosis - physiology; Caspase 3 - metabolism; Caspase-3 immunohistochemistry; Catfishes - metabolism; Clarias gariepinus; Freshwater; Immunohistochemistry; In Situ Nick-End Labeling; Male; Sharptooth catfish; Spermatocytes; Testis - cytology; Testis - metabolism; TUNEL; Caspase-3 immunohistochemistry; Clarias gariepinus; Spermatocytes; TUNEL; Sharptooth catfish; Apoptosis
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2008.03.017

This paper reports on the mechanistic basis of cellular death in the testis of Clarias gariepinus using the TUNEL and caspase-3 immunohistochemistry. It was also aimed to determine the testicular zone most suitable for the quantification of testicular apoptosis. The results showed that based on its immuno-expression patterns, activated caspase-3 has a clear and defined role in the progression of germ cell apoptosis in spermatogenically active catfish testis. Caspase-3 activation, and not TUNEL-detected DNA fragmentation, is associated with condensation of chromatin into a single mass. Testes of spermatogenically active catfish consist of spermatogenic, mature and spent tubules. Spermatogenic tubules were concluded to be the most suitable zone for the quantification of testicular cell death ratios as apoptotic events occurred predominantly in the secondary spermatocytes. The findings of this study will form the basis to link apoptotic events in the testes of C. gariepinus with the effects of EDC exposure in future studies.