Copper carbon dot induced multigeneration toxicity through Skp1/Cullin 1/F box-mediated ubiquitination and Wnt/β-catenin signal pathways in Caenorhabditis elegans

Abstract

Copper carbon dots (CuCDs) have garnered extensive research interest. However, their environmental persistence raises concerns about multigenerational ecotoxicological risks. Synchronized L1 larvae were exposed to CuCDs at concentrations of 0, 2, 6, and 10 mg mL⁻¹ in 24-well plates for 72 h. Here, we systematically evaluated six-generation (F0–F5) toxicological endpoints in Caenorhabditis elegans, including lethality, locomotor activity, reproductive output, developmental parameters, and lifespan. CuCD exposure induced dose-dependent phenotypic aberrations in the F1 generation: high lethality (42.22% increase vs. control group), impaired motility (37.7% reduction in lifespan; 22.69% reduction in body bends; 14.98% fewer head swings), reproductive failure (22.83% decreased egg-laying; 40% “bag of worms” incidence, 10% “fewer eggs” incidence), and developmental stunting (14.63% shorter body length) at high concentration. Across chronic CuCD exposure nematodes exhibited increasing tolerance to CuCDs in the F5 generation, with lethality significantly decreasing over time—a pattern aligning with known transgenerational adaptive responses. Notably, reproductive dysfunction was exacerbated, manifesting as a 29.74% reduction in egg-laying capacity and a 40% incidence of oviposition-deficient phenotypes (“fewer eggs”). Integrative transcriptomics and qRT-PCR validation revealed dysregulation of two core pathways: Skp1/Cullin 1/F box (SCF) ubiquitin ligase complex and Wnt/β-catenin signaling. Longitudinal tracking of Skr-8::mCherry fluorescence intensity revealed progressive transcriptional silencing, correlating with phenotypic penetrance. Crucially, SCF complex-mediated ubiquitination and Wnt signaling dyshomeostasis emerged as the central node to transgenerational reproductive and developmental toxicity.