Transgenerational toxicity induced by maternal AFB1 exposure in Caenorhabditis elegans associated with underlying epigenetic regulations

Abstract

Aflatoxin B₁ (AFB₁), usually seriously contaminates in grain and oil foods or feed, displayed significant acute and chronic toxic effects in human and animal populations. However, little is known about the transgenerational toxic effects induced by a maternal AFB₁ intake at a lower dose on offspring. In our study, only parental wild-type Caenorhabditis elegans was exposed to AFB₁ (0-8 μg/ml) and the following three filial generations were grown on AFB₁-free NGM. Results showed that the toxic effects of AFB₁ on the growth (body length) and reproduction (brood size, generation time and morphology of gonad arm) can be transmitted through generations. Moreover, the levels of MMP and ATP were irreversibly inhibited in the filial generations. By using RNomics and molecular biology techniques, we found that steroid biosynthesis, phagosome, valine/leucine/isoleucine biosynthesis and oxidative phosphorylation (p < 0.05) were the core signaling pathways to exert the transgenerational toxic effects on nematodes. Also, notably increased histone methylation level at H3K36me3 was observed in the first generation. Taken together, our study demonstrated that AFB₁ has notable transgenerational toxic effects, which were resulted from the complex regulatory network of various miRNAs, mRNAs and epigenetic modification in C. elegans.

Keywords: Aflatoxin B(1); Caenorhabditis elegans; Epigenetic inheritance; Reproductive development; Transgenerational toxicity.