Impact of cadmium on aquatic bird Cairina moschata

Abstract

The impact on palmiped Cairina moschata of two levels of dietary cadmium (Cd) contamination (C1: 1 mg kg(-1) and C10: 10 mg kg(-1)) was investigated on liver gene expression by real-time PCR. Genes involved in mitochondrial metabolism, in antioxidant defences, detoxification and in DNA damage repair were studied. Metallothionein (MT) protein levels and Cd bioaccumulation were also investigated in liver, kidneys and muscle. Male ducks were subjected to three periods of exposure: 10, 20 and 40 days. Cd was mainly bioaccumulated in kidneys first and in liver. The concentrations in liver and kidneys appeared to reach a stable level at 20 days of contamination even if the concentrations in muscle still increased. Cd triggered the enhancement of mitochondrial metabolism, the establishment of antioxidant defences (superoxide dismutase Mn and Cu/Zn; catalase) and of DNA repair from 20 days of contamination. Discrepancies were observed in liver between MT protein levels and MT gene up-regulation. MT gene expression appeared to be a late hour biomarker.

Evidence of species-specific detoxification processes for trace elements in shorebirds

“…Although the current results were below concentrations observed in previous studies where adult Barau's Petrel from the Reunion island were reported to have accumulated 66.8 ± 31.8 lg g -1 (Kojadinovic et al 2007), low environmental levels such as 4.7 ± 0.7 lg g -1 in the liver of birds experimentally contaminated could trigger the appearance of sub-lethal effects (Lucia et al 2009). Lucia et al (2009) observed the appearance of oxidative stress and up-regulation of genes involved in mitochondrial metabolism.…”

“…Lucia et al (2009) observed the appearance of oxidative stress and up-regulation of genes involved in mitochondrial metabolism. Cd is indeed able to inhibit the electron transfer chain and induce the production of reactive oxygen species (Wang et al 2004;Bertin and Averbeck 2006).…”

“…Nonetheless, in contrast to terrestrial birds and some waterbirds (e.g. Anatidae) for which oxidative stress related to trace elements has been demonstrated in the wild or experimentally (Hoffman et al 2000;Hoffman 2002;Mateo et al 2003;Berglund et al 2007;Lucia et al 2009), cellular damages due to trace elements are relatively unexplored in shorebirds. Filling in these gaps in the data is crucial for these endangered species.…”

Testicular toxicity induced by dietary cadmium in cocks and ameliorative effect by selenium

“…Moreover, Cd toxicity might be more common among natural populations of vertebrates than has been appreciated to date. The ingestion of even trace quantities of Cd can influence not only the physiology and health of individual organisms, but also the demographics and the distribution of species (Larison et al 2000;Lucia et al 2009). Accompanying population declines, there have been two shifts in lesser scaup (Aythya affinis) demographics: a decrease in the proportion of young birds and an increase in the male-to-female ratio (Pollock and Machin 2009).…”

Herbicide Impact on Seagrass Communities

“…The herbicide presence, even at limited concentrations, could lower such threshold temperature, considering the complex physiologic equilibrium that herbicides could disrupt; such temperature sensibility leads to an enhanced impact of herbicides in warm conditions [105]. Metal accumulation is enhanced by temperature increases [106].…”