Sub lethal mutagenic effects of glyphosate herbicides on juveniles of Clarias gariepinus using randomly amplified DNA primers

Abstract

The use of herbicides to control weeds has been recognized as a part of agricultural practices throughout the world. Unfortunately, the indiscriminate use of these herbicides to improve agricultural production and yield may have impacts on non-target organisms, especially aquatic life forms and their environment. This study is aimed at assessing the sub lethal mutagenic effects of selected glyphosate herbicides on juveniles of Clarias gariepinus using Randomly Amplified DNA primers. Molecular work was carried out in a standard Biotechnology Laboratory (the Bioinformatics Services), Queen Elizabeth Road, Ibadan, Oyo State, Nigeria. There were 4 levels of treatments per glyphosate formulation; each replicated thrice (one tank per replicate). Each tank contained 10 juveniles of C. gariepinus. The Quick-DNA Miniprep Kit was used for the DNA extraction, while Random Amplified Polymorphic DNA Based PCR was used for the amplification of the DNA strands. Plate 1 shows the gel image of genomic DNA extracted from C. gariepinus blood without gene amplification. (Plates 2-6) show the DNA amplicons obtained from random amplified primers of fish exposed to different glyphosate formulations at different sub lethal levels of concentrations as compared with the control treatment in order to check for possible mutation. Gel image of RAPD OPB04 primer (Plate 2) gave normal bands as in the control sample except in a sample exposed to Force-up glyphosate at 2.49 mg/L (B2) that gave a faint band. Genetic polymorphism was detected in amplicons of OPT10 primers (Plate 4) In OPT17 primer (Plate 5), there were no DNA bands in fish samples exposed to Force-up glyphosate at 4.98 mg/L (B3), Sunsate glyphosate at 1.21 mg/L (D2) and Touchdown glyphosate at 2.52 mg/L. (E2) or 5.03 mg/L (E3) levels. There were clear evidences of mutagenic effects of the glyphosates in C.gariepinus juveniles as established through the gel image of fish randomly amplified polymorphic DNA primers. The continuous use of the studied glyphosate formulation should be the concern of the public and regulatory bodies