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Quaternary ammonium compounds (QACs) become emerging pollutants and their toxicities earn increasing attention. 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 eleganswith a consecutive exposure over four generations (from F1 to F4). The effects of TTAC on total and initial reproduction showed stimulation and inhibition, which oscillated from F1 to F4. The effects of TTAB on the total reproduction commonly showed stimulation over generations with the greatest stimulation in F2, and it inhibited the initial reproduction but stimulated the reproduction duration. Further exploration demonstrated that TTAC and TTAB significantly disturbed the levels of spermatocyte protein 8 (SPE8), sperm transmembrane protein 9 (SPE9), vitellogenin (Vg), major sperm protein (MSP) and ephrin receptor protein tyrosine kinase (VAB-1) and the expressions of vab-1, ceh-18, set-2, met-2and mes-4. Such disturbances demonstrated that both QACs impacted the reproductive processes viaoocyte meiosis, gonadal support and germline development. Notably, the effects of TTAC and TTAB in parents were connected with those in the offspring, which highlighted the roles of reproduction in connecting generations. In addition, different effects between TTAC and TTAB demonstrated the anionic influences on the QACs’ toxicities.

Antibiotics are emerging pollutants with pseudo-persistence. However, their reproductive toxicities over generations and underlying mechanisms were seldom explored. In the present study, reproductive effects of erythromycin(ERY) and sulfamethoxazole(SMZ) were studied on Caenorhabditis elegans(C. elegans) with multi-generational exposure from F1 to F4, and their effects in the non-direct exposed offspring of F1 and F4(T4 and T4’) were explored to investigate trans-generational outcomes. At high concentrations, ERY and SMZ inhibited the reproduction and the inhibition decreased with more generations’ exposure. At low concentrations, SMZ stimulated reproduction in T4, opposite to its inhibition in F1. Further analysis on ten enzymes and proteins in lipid and glucolipid metabolism showed that ERY commonly inhibited fatty acid synthetase(FAS) in F1 to F4, while ERY and SMZ showed stimulation and inhibition on other biochemicals. Integrated biomarker response(IBR) index values showed that ERY and SMZ stimulated the overall metabolism in F1, and the stimulation decreased and even altered to inhibition in later generations. When comparing multi- and trans-generational effects, ERY and SMZ at high concentration caused inhibition on reproduction in T4 and stimulation in T4’, which were opposite to those in F1 and F4.