Genotoxic Effects of Cassava Effluent on the Expression of Selected Genes in the African Catfish, Clarias gariepinus

Aim: A cause for worry is the wastewater that is released into the environment or public sewers without any sort of purpose during the processing of Manihot esculenta Crantz. Fish and other aquatic species may suffer negative consequences if wastewater is discharged into streams and rivers, either directly or indirectly. This study was conducted to examine the effects of cassava effluents on gene expression in the African catfish (Clarias gariepinus).

Methodology: C. gariepinus juveniles were exposed to 0.1, 0.5, 1.0 and 1.5 % concentrations of cassava effluent, respectively. The subsequent tissue extraction, RNA isolation, cDNA synthesis and electrophoresis analysis were all done following standard procedures.

Results: From the results obtained, there were varying levels of upregulation in the expression levels of all the nine genes assessed: IL-1β, CYPIIA, HSP70, DMRTI, HSD17B, FOX12, MEL1C, CAMKIIg and GH genes. Statistical analysis to compare the expression levels of the genes at the different concentrations with their corresponding control experiments showed that the upregulation of only two genes, (HSD17B and GH), upon exposure to cassava effluents were not significant (p >0.05) at any concentration. The upregulation of the seven other genes is an indication that the cassava effluents exerted adverse impacts on the physiology of C. gariepinus.

Conclusion: It is therefore recommended that cassava effluents be properly treated before being discharged into the aquatic environment.