Reproductive toxicities of tetradecyltrimethylammonium chloride and tetradecyltrimethylammonium bromide on Caenorhabditis elegans over four consecutive generations

Abstract

Abstract Quaternary ammonium compounds (QACs) become emerging pollutants and their toxicities earn increasing attentions. So far, their reproductive toxicities were poorly investigated, and their effects over generations were even less explored. In the present study, reproductive toxicities of two QACs, i.e., tetradecyltrimethylammonium chloride (TTAC) and tetradecyltrimethylammonium bromide (TTAB) were studied on Caenorhabditis elegans with a consecutive exposure over four generations (from F1 to F4). The effects of TTAC on total reproduction showed stimulation and inhibition which oscillated from F1 to F4, and such oscillation was also observed in the effects on initial reproduction. The effects of TTAB on the total reproduction commonly showed stimulation over generations. The greatest stimulation was in F2, and it was accompanied with inhibition on the initial reproduction but stimulation on the reproduction duration. Further mechanisms exploration demonstrated that both TTAC and TTAB significantly disturbed the levels of SPE8, SPE9, Vg, MSP and VAB-1 and the expressions of vab-1, ceh-18, set-2, met-2 and mes-4 over generations. Such disturbances demonstrated that both QACs impacted the reproductive processes in multiple aspects including oocyte meiosis, gonadal support and germline development. Further analysis also showed that the effects of both TTAC and TTAB in parents were connected with those in the offspring, which highlighted the conjunctive roles of reproduction in responses of adjacent generations. In addition, the differences the effects of TTAC and TTAB also demonstrated the anionic influences on the QACs’ toxicities.