Technological watch

Contaminants are selective agents that influence the fitness and population dynamics of organisms, and their strength partially depends on both parents and the environment. In this study, the toxic effects of brominated flame retardant 2,2?,4,4?-tetrabromodiphenyl ether (BDE-47) and its UV-B-photodegradation product 2,4,4?-tribromodiphenyl ether (BDE-28) on the growth and reproduction of marine rotifer Brachionus plicatilis were investigated, and their intergenerational transfer through parthenogenesis to the offspring was also studied. Both BDE-47 and BDE-28 were effectively transferred from maternal rotifers to amictic eggs, and the accumulation of BDE-47 in the irradiated group was greater than that in the standard BDE-47 group because of the production of BDE-28 by photolysis. At the medium-level (0.1 mg/L), BDE-47 had significant positive effects on the survival, growth, and reproduction of the F1 generation, whereas the high-level treatment (0.5 mg/L) impaired offspring performance. Irradiated BDE-47 had similar but generally more pronounced effects. Notably, BDE-47 exposure significantly increased the proportion of male offspring in the F1 generation, consequently triggering the reproductive mode shift from parthenogenesis to sexual reproduction. Maternal effects played a pivotal role in offspring adaptation to BDE-47 stress. The results of gas chromatography analysis combined with changes in digestive enzyme activity revealed that exposure of maternal rotifers to BDE-47 increased the supply of three nutrient substances to amictic eggs by regulating digestive enzyme activity, thereby ensuring offspring quality and population sustainability.