The effects of cadmium on the development of Drosophila and its transgenerational inheritance effects

A new focus in toxicology research is the impact of parental exposure to environmental toxic substances on the characteristics of offspring. In the present study, newly produced eggs of Drosophila melanogaster were treated with different concentrations of cadmium (0, 1, 2, 4, 8 mg/kg) to study the effects of development. The results showed that cadmium changed the larval body length and weight, prolonged the pupation and eclosion time, and changed the relative expression levels of development-related genes (baz, beta-Tub60D, tj). Furthermore, the parental Drosophila (F-0) were treated with cadmium (4.5 mg/kg) from egg stage, and when grows to adults, they mated in standard medium to produce the de-stressed offspring (F-1-F-4) to assess the transgenerational effects of developmental delay. The results showed that the delayed effects of the pupation and eclosion time could be maintained for two generations, and the inhibiting effects of juvenile hormone (JH) and ecdysone (20-hydroxyecdysone, 20E) could be maintained for two or three generations. More importantly, cadmium increased the expression of DNA methylation-related genes (dDnmt2, dMBD2/3) in the ovaries (F-0-F-2) and testicles (F-0 and F-1). In addition, cadmium accumulated in parental Drosophila (F-0) was not transmitted to offspring through reproductive pathway. These results demonstrate that the developmental toxicity caused by cadmium could be transmitted to the de-stressed offspring, and the observed transgenerational inheritance effects may be associated with epigenetic regulation, underscoring the need to consider fitness of future generations in evaluating the toxicity and environmental risks of cadmium.

Automated summary

The study revealed that cadmium exposure on Drosophila eggs can alter offspring development, affecting body length, weight, pupation and eclosion time, as well as gene expression levels. These effects can persist for multiple generations and may be mediated through epigenetic regulation rather than direct transmission through reproductive pathways. The findings underscore the importance of considering future generation fitness when evaluating the toxicity and environmental risks associated with cadmium.