Reproductive Toxicities of Tetradecyltrimethylammonium Chloride and Tetradecyltrimethylammonium Bromide on Caenorhabditis elegans over Four Consecutive Generations

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);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 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);ephrin receptor protein tyrosine kinase (VAB-1);the expressions of vab-1,ceh-18,set-2,met-2 and mes-4.Such disturbances demonstrated that both QACs impacted the reproductive processes via oocyte 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.

Sex-dependent obesogenic effect of tetracycline on Drosophila melanogaster deteriorated by dysrhythmia

Antibiotics have been identified as obesogens contributing to the prevalence of obesity.Moreover,their environmental toxicity shows sex dependence,which might also explain the sex-dependent obesity observed.Yet,the direct evidence for such a connection and the underlying mechanisms remain to be explored.In this study,the effects of tetracycline,which is a representative antibiotic found in both environmental and food samples,on Drosophila melanogaster were studied with consideration of both sex and circadian rhythms(represented by the eclosion rhythm).Results showed that in morning-eclosed adults,tetracycline significantly stimulated the body weight of females(AM females)at 0.1,1.0,10.0 and 100.0μg/L,while tetracycline only stimulated the body weight of males(AM males)at 1.0μg/L.In the afternoon-eclosed adults,tetracycline significantly stimulated the body weight of females(PM females)at 0.1,1.0 and 100.0μg/L,while it showed more significant stimulation in males(PM males)at all concentrations.Notably,the stimulation levels were the greatest in PMmales among all the adults.The results showed the clear sex dependence of the obesogenic effects,which was diminished by dysrhythmia.Further biochemical assays and clustering analysis suggested that the sex-and rhythm-dependent obesogenic effects resulted from the bias toward lipogenesis against lipolysis.Moreover,theywere closely related to the preference for the energy storage forms of lactate and glucose and also to the presence of excessive insulin,with the involvement of glucolipid metabolism.Such relationships indicated potential bridges between the obesogenic effects of pollutants and other diseases,e.g.,cancer and diabetes.

Reproductive Influences of Erythromycin and Sulfamethoxazole on Caenorhabditis elegans over Generations Mediated by Lipid Metabolism

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.