Effects of cadmium on female Drosophila melanogaster and its transgenerational inheritance effects

Cadmium (Cd) is a silvery-white and shiny heavy metal that is common in daily life and can adversely affect the development, lifespan, and reproduction of organisms. In this study, Drosophila melanogaster (F₀) were cultured from eggs to adults in medium containing different Cd concentrations (0, 2.25, and 4.5 mg/kg), and offspring (F₁-F₄ generations) were cultured in standard medium. The morphology of the ovaries of female flies under Cd stress changed, apoptosis occurred, fertility decreased, and the levels of 20-Hydroxyecdysone and vitellogenin decreased significantly. These changes were more significant under high-concentration treatment. In addition, the inhibitory effects of Cd on reproduction-related genes (spook, phantom, disembodies, shadow, shade, ECR, vg, and Kr-h1) in F₀ female flies could transmit to two or three generations. Cd exposure also induced increased expression of miR-927 and mediated its transgenerational inheritance. These results indicate that damage to the ovaries and the changes in related-genes expressions of female flies induced by Cd stress can be transmitted to offspring and may be related to changes in miRNA expression in Drosophila. The transgenerational inheritance effects of heavy metals on organisms and their potential risks to future ecosystems deserve attention and reassess.