Effect of cadmium on cytosine hydroxymethylation in gastropod hepatopancreas

Abstract

5-Hydroxymethylcytosine (5hmC) is an important, yet poorly understood epigenetic DNA modification, especially in invertebrates. Aberrant genome-wide 5hmC levels have been associated with cadmium (Cd) exposure in humans, but such information is lacking for invertebrate bioindicators. Here, we aimed to determine whether this epigenetic mark is present in DNA of the hepatopancreas of the land snail Cantareus aspersus and is responsive to Cd exposure. Adult snails were reared under laboratory conditions and exposed to graded amounts of dietary cadmium for 14 days. Weight gain was used as a sublethal endpoint, whereas survival as a lethal endpoint. Our results are the first to provide evidence for the presence of 5hmC in DNA of terrestrial mollusks; 5hmC levels are generally low with the measured values falling below 0.03%. This is also the first study to investigate the interplay of Cd with DNA hydroxymethylation levels in a non-human animal study system. Cadmium retention in the hepatopancreas of C. aspersus increased from a dietary Cd dose of 1 milligram per kilogram dry weight (mg/kg d. wt). For the same treatment, we identified the only significant elevation in percentage of samples with detectable 5hmC levels despite the lack of significant mortalities and changes in weight gain among treatment groups. These findings indicate that 5hmC is an epigenetic mark that may be responsive to Cd exposure, thereby opening a new aspect to invertebrate environmental epigenetics.

Studies on Toxicity of Suspensions of CdTe Quantum Dots to Biomphalaria glabrata Mollusks

“…Thus our ICP‐MS results corroborate studies reported earlier (Rocha et al ; Rocha et al ; Nica et al ). Moreover, these findings also led us to suppose that cadmium exposure alone does not reflect the overall toxicity of suspensions of quantum dots to adult B. glabrata mollusks.…”

“…also found a lower accumulation when M. galloprovincialis were exposed to quantum dots or cadmium ions, with a relative percentage of approximately 3.4 and 14%, respectively. Thus our ICP-MS results corroborate studies reported earlier (Rocha et al 2014;Rocha et al 2015a;Nica et al 2017). Moreover, these findings also led us to suppose that cadmium exposure alone does not reflect the overall toxicity of suspensions of quantum dots to adult B. glabrata mollusks.…”

Effects of Cadmium Sulfate on the Brown Garden Snail Cornu aspersum: Implications for DNA Methylation

“…Cadmium (Cd) is a non-essential trace metal classified as a global priority pollutant due to its environmental persistence, bio-accumulative nature, and high toxicity at low ambient concentrations [1][2][3]. Decades of toxicological research have yielded a compelling body of evidence for the cellular, physiological, and genetic implications of exposure to Cd and its compounds [2,4,5].…”

Short-term effects of very low dose cadmium feeding on copper, manganese and iron homeostasis: A gastropod perspective

“…Numerous studies have examined the retention of dietary cadmium in the soft tissues of land snails (Russell et al, 1981;Berger and Dallinger, 1989;Laskowski and Hopkin, 1996;Gomot, 1997;Notten et al, 2006;Gimbert et al, 2008;, but not at very low, but environmentally-relevant dietary levels below 0.1mg/kg dw (Nica et al, 2017b). In the current study, a 28-day exposure to doses as low as 0.2 mg/kg dw Cd (as cadmium sulfate) yielded significantly elevated hepatopancreas cadmium levels.…”

“…Cadmium sulfate will extend our knowledge on the bioavailability of different chemical forms of Cd in land snails, which is currently limited to cadmium chloride (Coeurdassier et al, 2002;Nica et al, 2015;Nica et al, 2017aNica et al, , 2017b and cadmium nitrate (Laskowski and Hopkin, 1996).…”