Multigenerational toxicity and transcriptomic changes induced by environmentally relevant concentrations of microcystin-LR and -RR in Caenorhabditis elegans

Microcystin (MC) contamination in surface water is currently receiving considerable attention as a public health concern. Seasonal occurrence MCs in aquatic environment suggests their long-term impacts on ecosystem and human health, whereas multi-generational toxic effects of MCs were poorly investigated. The reproductive system is the second most important target organ of MCs after the liver. In this study, we examined reproductive toxic effects of the two most prevalent MCs (MC-LR and -RR) on three successive generations of Caenorhabditis elegans through parental exposure, and conducted transcriptomic analysis on P0 and F1 worms. Our results show that parts-per-billion levels of MC-LR and MC-RR disrupt germ cell development in both parental worms and non-exposed F1/F2 progeny. Significant up-regulation of antimicrobial peptide genes was observed in parental worms, while F1 offspring exhibited decreased expression levels of cytochrome P450 genes. The findings reveal multi-generational effects of environmentally relevant concentrations of MCs on reproductive system, and illustrate possible transcriptional changes associated with long term toxicity of MCs.