Exposure to polystyrene microplastic beads causes sex-specific toxic effects in the model insect Drosophila melanogaster

Abstract

The toxicity of MPs on aquatic creatures has been extensively studied, but little attention was paid to terrestrial organisms. To fill this gab, we conducted a series of experiments using Drosophila as a model organism to understand whether exposure to different concentrations (0.005, 0.05, 0.5 µg/ml) of polystyrene microplastics (PS-MPs) beads (2 µm in size) can impact flies feeding activity, digestion and excretion. The ability of flies to distinguish between normal and PS-MPs treated food media was tested first, and then we evaluated the effects of a 7-day short-term exposure to PS-MPs on food intake, mortality, starvation resistance, fecal pellet count, and the cellular structure of mid gut cells. The results revealed that flies can really differentiate and ignore MPs-treated food. We discovered sex-specific effects, with male flies being more sensitive to PS-MPs, with all males dying after 14 days when exposed to 0.5 µg/ml of PS-MPs, whereas female flies survived more. All male flies exposed to PS-MPs died after 24 h of starvation. Midgut cells showed concentration-dependent necrosis and apoptosis in response to PS-MPs. Our findings provide new insights into MPs toxicity on terrestrial organisms and giving a warning that management measures against MPs emission must be taken.

<i>Drosophila melanogaster</i> as potential alternative animal model for evaluating acute inhalation toxicity

“…This study revealed that the mortality rates were influenced by sex following acute inhalation exposure to CMIT/MIT. These findings are consistent with previous studies that have demonstrated sex-specific responses in parameters of toxicity, such as survival rate, in the D. melanogaster model (El Kholy and Al Naggar, 2023). Moreover, transcriptional alterations and metabolic responses were also shown to be sex-specific impacts on this model (Brown et al, 2021).…”

Chronic Exposure to Polystyrene Microplastic Fragments Has No Effect on Honey Bee Survival, but Reduces Feeding Rate and Body Weight

“…Although previous research has shown that the toxicity of microplastics may vary with concentration [ 47 , 48 ], significant differences in bee body weight and sugar syrup consumption were only observed at 10 g/mL, not at 100 g/mL of both sizes of PS-MS, in the current study. Even though the cause is unknown, e.g., through disruption of the gut microbiota vs. direct physical impact on the host gut, our results are consistent with previous research that found a significant decrease in the consumption of sugar syrup by honey bees ( A. mellifera ) exposed to PS-MPs spheres at the lowest concentrations (10 mg/L vs. 100 mg/L) [ 21 ], (0.5 vs. 5 or 50 mg/L) [ 22 ].…”

Independent and synergistic effects of microplastics and endocrine‐disrupting chemicals on the reproductive social behavior of fathead minnows (Pimephales promelas)

“…Female Eastern mosquitofish ( Gambusia holbrooki ) exposed to TB also showed a decrease in the amount of time that they interacted with males compared to non‐exposed fish, whereas exposed and non‐exposed males showed no differences in reproductive behavior (Saaristo et al., 2013 ). Although there is limited research evaluating the potential for sex‐specific effects of MP exposure on aquatic species, male Drosophila melanogaster were reported to have a higher mortality than female flies after exposure (Kholy & Naggar, 2023 ). In the common European hermit crab, Pagurus bernhardus , exposure to MPs decreased the time taken by females to select and enter shells compared to males; however, they were also more likely to choose high‐quality shells (McDaid et al., 2023 ).…”