Changes in microtubule stability in zebrafish (Danio rerio) embryos after glyphosate exposure

Glyphosate, the most commonly used pesticide worldwide, blocks aromatic amino acid biosynthetic pathways and inhibits growth in plants. Although the specific mode of action of glyphosate in animals remains unclear, adverse effects during embryonic development have been reported, including epiboly delays, morphological alterations, and changes in central nervous system development and cardiogenesis. In this study, we suggest a possible toxicity mechanism for this herbicide related to changes in microtubule stability, which could alter the distribution and dynamics of cytoskeleton components. Using zebrafish embryos to evaluate in vivo effects of glyphosate exposure (5, 10, and 50 mu g/ml), we found significant reductions in the levels of acetylated alpha-tubulin (50 mu g/ml) and in the polymeric tubulin percentage in zebrafish embryos that had been exposed to 10 and 50 mu g/ml glyphosate, without any changes in either the expression patterns of alpha-tubulin or the stability of actin filaments. These results indicate that high concentrations of glyphosate were associated with reduced levels of acetylated alpha-tubulin and altered microtubule stability, which may explain some of the neurotoxic and cardiotoxic effects that have been attributed to this herbicide.