Tolerance towards environmental stress has been frequently considered as one of the key determinants of invasion success. However, empirical evidence supporting the assumption that invasive species ...can better endure unfavorable conditions compared with native species is limited and has yielded opposing results. In this study, we examined the tolerance to different stress conditions (thermal stress and trace metal zinc pollution stress) in two phylogenetically related and functionally similar freshwater bivalve species, the native Anodonta anatina and the invasive Sinanodonta woodiana. We assessed potential differences in response to stress conditions using several cellular response assays: efficiency of the multixenobiotic resistance mechanism, respiration estimate (INT reduction capacity), and enzymatic biomarkers. Our results demonstrated that the invasive species overall coped much better with unfavorable conditions. The higher tolerance of S. woodiana was evident from (i) significantly decreased Rhodamine B accumulation indicating more efficient multixenobiotic resistance mechanism; (ii) significantly higher INT reduction capacity and (iii) less pronounced alterations in the activity of stress-related enzymes (glutathione-S-transferase, catalase) and of a neurotoxicity biomarker (cholinesterase) in the majority of treatment conditions in both stress trials. Higher tolerance to thermal extremes may provide physiological benefit for further invasion success of S. woodiana in European freshwaters, especially in the context of climate change.
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•We compared tolerance to anthropogenic stress in invasive vs. native mussels.•Animals were exposed to thermal stress and trace metal zinc pollution.•RB accumulation, INT reduction capacity and enzymatic biomarkers were measured.•Invasive bivalve showed higher tolerance to unfavourable conditions.•Thermal stress tolerance could facilitate invasion in the context of climate change.
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•Multi-biomarker testing of BPA toxicity using Eisenia fetida as model organism.•Cutaneous exposure to low doses of BPA.•Maximal BPA accumulation reached after 10-d exposure.•BPA ...caused oxidative stress and multiple histopathological changes.•Behavioural changes detected after 3days of exposure to 100nM BPA.
Bisphenol A (BPA) presents a serious threat to soil ecosystems, yet its effects on soil-inhabiting organisms are mostly unexplored. Therefore, the impact of environmentally relevant BPA concentrations on a terrestrial model organism, the earthworm Eisenia fetida, was assessed. Animals were cutaneously exposed to 100nM and 10μM BPA up to 10days (10-d). Next, a battery of biomarkers was used for ecotoxicological evaluation on a cellular, tissue and behavioural level. HPLC analysis showed that after a 10-d exposure, BPA accumulation reached a maximum of 2.50μg BPA per g of wet tissue weight. On the cellular level, up to 3-d BPA exposure caused increased lipid oxidation indicating oxidative stress. Histopathological assessment of cell wall and ovaries after 7- and 10-d BPA exposure showed multiple abnormalities, i.e. hyperplasia of epidermis, increased body wall thickness and ovarian atrophy. Detection of these changes was facilitated by a newly proposed semi-quantitative scoring system. Finally, behavioural changes were detected after only 3days of exposure to 100nM BPA. Altogether, the presented multilevel toxicity evaluation indicates high sensitivity of earthworms to low BPA doses.
Green bridges are used to decrease highly negative impact of roads/highways on wildlife populations and their effectiveness is evaluated by various monitoring methods. Based on the 3-year monitoring ...of four Croatian green bridges, we compared the effectiveness of three indirect monitoring methods: track-pads, camera traps and active infrared (IR) trail monitoring system. The ability of the methods to detect different species and to give good estimation of number of animal crossings was analyzed. The accuracy of species detection by track-pad method was influenced by granulometric composition of track-pad material, with the best results obtained with higher percentage of silt and clay. We compared the species composition determined by track-pad and camera trap methods and found that monitoring by tracks underestimated the ratio of small canids, while camera traps underestimated the ratio of roe deer. Regarding total number of recorder events, active IR detectors recorded from 11 to 19 times more events then camera traps and app. 80% of them were not caused by animal crossings. Camera trap method underestimated the real number of total events. Therefore, an algorithm for filtration of the IR dataset was developed for approximation of the real number of crossings. Presented results are valuable for future monitoring of wildlife crossings in Croatia and elsewhere, since advantages and disadvantages of used monitoring methods are shown. In conclusion, different methods should be chosen/combined depending on the aims of the particular monitoring study.
Mercuric compounds are persistent global pollutants that accumulate in marine organisms and in humans who consume them. While the chemical cycles and speciation of mercury in the oceans are ...relatively well described, the cellular mechanisms that govern which forms of mercury accumulate in cells and why they persist are less understood. In this study we examined the role of multidrug efflux transport in the differential accumulation of inorganic (HgCl(2)) and organic (CH(3)HgCl) mercury in sea urchin (Strongylocentrotus purpuratus) embryos. We found that inhibition of MRP/ABCC-type transporters increases intracellular accumulation of inorganic mercury but had no effect on accumulation of organic mercury. Similarly, pharmacological inhibition of metal conjugating enzymes by ligands GST/GSH significantly increases this antimitotic potency of inorganic mercury, but had no effect on the potency of organic mercury. Our results point to MRP-mediated elimination of inorganic mercury conjugates as a cellular basis for differences in the accumulation and potency of the two major forms of mercury found in marine environments.
•Effects of BPA on embryonic development of Paracentrotus lividus were determined.•Transport assay, intracellular BPA measurements and gene expression surveys were made.•Multidrug efflux transporter ...P-gp/ABCB1 is involved in BPA elimination.•Endocrine disruption is inferred by orphan steroid hormone receptor (shr2) upregulation.•BPA delayed mitosis, inducing aberrant karyokinesis and dysfunctional microfilaments.
Usage of bisphenol A (BPA) in production of polycarbonate plastics has resulted in global distribution of BPA in the environment. These high concentrations cause numerous negative effects to the aquatic biota, among which the most known is the induction of endocrine disruption. The focus of this research was to determine the effects of two experimentally determined concentrations of BPA (100nM and 4μM) on cellular detoxification mechanisms during the embryonic development (2-cell, pluteus) of the rocky sea urchin (Paracentrotus lividus), primarily the potential involvement of multidrug efflux transport in the BPA intercellular efflux. The results of transport assay, measurements of the intracellular BPA and gene expression surveys, for the first time indicate the importance of P-glycoprotein (P-gp/ABCB1) in defense against BPA. Cytotoxic effects of BPA, validated by the immunohistochemistry (IHC) and the transmission electron microscopy (TEM), induced the aberrant karyokinesis, and consequently, the impairment of embryo development through the first cell division and retardation.
A multixenobiotic resistance (MXR) mechanism mediated by ABC binding cassette (ABC) transport proteins is an efficient chemical defence mechanism in sea urchin embryos. The aim of our work was to ...evidence whether exposure to sub-lethal doses of specific contaminants (oxybenzone (OXI), mercuric chloride (HgCl
2
) and trybutiltin (TBT)) would induce MXR transporter activity during embryonic development (from zygote to blastula stage) in purple sea urchin (
Paracentrotus lividus
) embryos. Further, we present data on molecular identification, transport function, expression levels and gene localisation of two ABC efflux transporters—P-glycoprotein (ABCB1/P-gp) and sulfonylurea-receptor-like protein (ABCC9/SUR-like). Partial cDNA sequences of
abcb1
and
abcc9
were identified and quantitative PCR (qPCR) evidenced an increase in mRNA transcript levels of both ABC transporters during the two-cell, as well as an overall decrease during the blastulae stage. Calcein-AM efflux activity assay indicated the activation of multidrug resistance-associated protein/ABCC-like transport in the presence of HgCl
2
and TBT in exposed blastulae. The in situ hybridisation of the two-cell and blastula stages showed ubiquitous localisation of both transcripts within cells, supporting qPCR data. In conclusion, ABCB1 and ABCC9 are constitutive, as are HgCl
2
, TBT and OXI-inducible ABC membrane transporters, coexpressed in the zygote, two-cell and blastula stages of the
P
.
lividus
. Their ubiquitous cell localisation further fortifies their protective role in early embryonic development.
The main goals of this study were (1) to standardize a simple and reliable embryotoxicity test for environmental contaminants and (2) to evaluate the presence and possible protective role of the ...multidrug resistance-associated (MRP) protein-mediated multixenobiotic defense in two Mediterranean sea urchin species,
Paracentrotus lividus
and
Arbacia lixula.
Toxic end-point used was the success of the first cell division in sea urchin embryos. Embryotoxicities of three environmentally relevant contaminants: mercuric chloride (HgCl
2
, 0.05–6 μM), trybutiltin (TBT, 2.5–500 nM), and oxybenzone (OXI, 0.1–100 μM); as well as seawater samples collected from the polluted and unpolluted locations, were determined and compared.
A. lixula
embryos were more sensitive to all three toxic compounds, and both
P. lividus
and
A. lixula
embryos were highly sensitive to TBT at nanomolar concentrations (EC
50
49 ± 5 and 36.8 ± 3 nM, respectively). Inhibition of MRP protein by specific inhibitor MK571 caused significant increase in embryotoxic potency of HgCl
2
(EC
50
0.697 ± 0.03 and 0.245 ± 0.04 μM, respectively), TBT (EC
50
24 ± 3 and 7.4 ± 1 nM, respectively) and polluted seawater sample, but not of OXI or unpolluted, natural seawater. Therefore, our results demonstrated for the first time the protective relevance of MRP proteins in early development of these two Mediterranean sea urchin species. Finally, the embryotoxicity protocol described in this study represents a simple and rapid bioassay for determination of environmentally relevant seawater contamination.
Mussel (Mytilus galloprovincialis (Lamarck, 1819)) is directly exposed to sea water contamination that elicits significant physiological and cellular response, although its extent mounted in ...aquaculture-reared in comparison to wild bivalve populations is scarcely known. Therefore, we have compared contamination biomarkers in mussels from reared (Marina farm) and wild, anthropogenically affected site (Vranjic Bay). While predictably, the levels of metals (Cu, Cd, Pb, Zn, Fe, and Hg) in whole bivalve tissues determined by atomic absorption spectrophotometry resulted in significantly higher concentrations in wild mussels, accompanied by elevated number of apoptotic cells in gills, the activity of multixenobiotic resistance defense mechanism (MXR), measured as the accumulation rate of model substrate rhodamine B (RB) gave contrasting results. The functional RB assay evidenced a lower MXR efflux activity in the gill tissue of wild mussels, indicating two possible scenarios that will need further focus: (1) persisting sea water pollution increased cell damage of bivalve gill cells and consequently led to leakage of the RB into cytoplasm and dysfunctional MXR efflux in wild mussels; or/and (2) a mixture of different toxic compounds present in Vranjic Bay sea water induced oversaturation of MXR efflux, inducing elevated accumulation of the dye. Consequently, it seems that an efficient physiological functioning of MXR in wild mussels is strongly hampered by existence of an unknown quantity of sea water pollutants that may endanger intrinsic organismal defense system and lead toward the enhancement of toxicity.
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