Survival, growth and digestive functions after exposure to nanodiamonds - Transgenerational effects beyond contact time in house cricket strains

The long-term exposure effects of nanodiamonds (NDs), spanning an organism's entire lifespan and continuing for subsequent generation, remain understudied. Most research has focused on evaluating their biological impacts on cell lines and selected organisms, typically over short exposure durations lasting hours or days. The study aimed to assess growth, mortality, and digestive functions in wild (H) and long-lived (D) strains of Acheta domesticus (Insecta: Orthoptera) after two-generational exposure to NDs in concentrations of 0.2 or 2 mg kg-1 of food, followed by their elimination in the third generation. NDs induced subtle stimulating effect that depended on the strain and generation. In the first generation, more such responses occurred in the H than in the D strain. In the first generation of H strain insects, contact with NDs increased survival, stimulated the growth of young larvae, and the activity of most digestive enzymes in mature adults. The same doses and exposure time did not cause similar effects in the D strain. In the first generation of D strain insects, survival and growth were unaffected by NDs, whereas, in the second generation, significant stimulation of those parameters was visible. Selection towards longevity appears to support higher resistance of the insects to exposure to additional stressor, at least in the first generation. The cessation of ND exposure in the third generation caused potentially harmful changes, which included, e.g., decreased survival probability in H strain insects, slowed growth of both strains, as well as changes in heterochromatin density and distribution in nuclei of the gut cells in both strains. Such a reaction may suggest the involvement of epigenetic inheritance mechanisms, which may become inadequate after the stress factor is removed.

Adaptation by death? Cell death-based tolerance to cadmium in 150-generation exposure of Spodoptera exiqua Hübner (Lepidoptera: Noctuidae)

Mechanisms, including autophagy and apoptosis, which serve to regulate and ensure proper organism functions under optimal conditions, play additional defensive roles under environmental pressure. The aim of this study was to test the following hypotheses: (i) elevated autophagy and apoptosis intensity levels, as defensive processes in response to contact with cadmium, are maintained for a limited number of generations and (ii) the number of generations after which levels of cell death processes reach the reference level depends on selective pressure. Cell death processes were assessed by light and transmission electron microscopy, terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNEL), and cytometric analyses. Model insects (Spodoptera exiqua, Hübner, 1808) were orally exposed to various concentrations of cadmium for 18 generations and compared with reference strains exposed to cadmium or not (control) for over 150 generations. Elevated programmed cell death intensity levels decreased after several generations, indicating tolerance of individuals to cadmium in the diet and verifying the first hypothesis; however, testing the second hypothesis indicated that the number of generations depended not only on pressure intensity, but also on cell death type, since levels of autophagy remained increased for a minimum of 12 generations.

Multigenerational Effects of Graphene Oxide Nanoparticles on Acheta domesticus DNA Stability

The use of nanoparticles like graphene oxide (GO) in nanocomposite industries is growing very fast. There is a strong concern that GO can enter the environment and become nanopollutatnt. Environmental pollutants' exposure usually relates to low concentrations but may last for a long time and impact following generations. Attention should be paid to the effects of nanoparticles, especially on the DNA stability passed on to the offspring. We investigated the multigenerational effects on two strains (wild and long-lived) of house cricket intoxicated with low GO concentrations over five generations, followed by one recovery generation. Our investigation focused on oxidative stress parameters, specifically AP sites (apurinic/apyrimidinic sites) and 8-OHdG (8-hydroxy-2'-deoxyguanosine), and examined the global DNA methylation pattern. Five intoxicated generations were able to overcome the oxidative stress, showing that relatively low doses of GO have a moderate effect on the house cricket (8-OHdG and AP sites). The last recovery generation that experienced a transition from contaminated to uncontaminated food presented greater DNA damage. The pattern of DNA methylation was comparable in every generation, suggesting that other epigenetic mechanisms might be involved.

Joint cadmium and polypropylene microparticle action in cadmium tolerant model insect

Microplastic enlisted as a contaminant of emerging concerns in polluted environments interact with "traditional" contaminants such as metals, causing, among others, their increased accumulation in the body. Harmful effects depend on the exposed animals' possible preadaptation and/or cross-tolerance. The project aimed to assess the role of this phenomenon in the limited toxicity of polypropylene fibers (PPf) in 0%, 0.02%, 0.06, 0.18%, 0.54%, and 1.6% of Cd-supplemented food of larvae of Spodoptera exigua multigenerationally selected to cadmium tolerance. The activity of 20 digestive enzymes (API-ZYM test), defensins, and heat shock proteins, HSP70 levels in the exposed groups were used as biomarkers. PPfs caused the increase of Cd accumulation in the body, while intake of polypropylene microfibers did not change the biomarker levels. Moreover, multigenerational Cd pre-exposure, due to increased tolerance of Cd and, possibly, cross-tolerance, prepares the insects for an additional stressor (PPf) alone and in interaction with cadmium.

Age- and Lifespan-Dependent Differences in GO Caused DNA Damage in Acheta domesticus

The rising applicability of graphene oxide (GO) should be preceded by detailed tests confirming its safety and lack of toxicity. Sensitivity to GO of immature, or with different survival strategy, individuals has not been studied so far. Therefore, in the present research, we focused on the GO genotoxic effects, examining selected parameters of DNA damage (total DNA damage, double-strand breaks-DSB, 8-hydroxy-2'-deoxyguanosine-8-OHdG, abasic site-AP sites), DNA damage response parameters, and global methylation in the model organism Acheta domesticus. Special attention was paid to various life stages and lifespans, using wild (H), and selected for longevity (D) strains. DNA damage was significantly affected by stage and/or strain and GO exposure. Larvae and young imago were generally more sensitive than adults, revealing more severe DNA damage. Especially in the earlier life stages, the D strain reacted more intensely/inversely than the H strain. In contrast, DNA damage response parameters were not significantly related to stage and/or strain and GO exposure. Stage-dependent DNA damage, especially DSB and 8-OHdG, with the simultaneous lack or subtle activation of DNA damage response parameters, may result from the general life strategy of insects. Predominantly fast-living and fast-breeding organisms can minimize energy-demanding repair mechanisms.

Does age pay off? Effects of three-generational experiments of nanodiamond exposure and withdrawal in wild and longevity-selected model animals

Nanodiamonds (NDs) are considered a material with low toxicity. However, no studies describe the effects of ND withdrawal after multigenerational exposure. The aim was to evaluate ND exposure (in the 1st and 2nd generations) effects at low concentrations (0.2 or 2 mg kg^-1) and withdrawal (in the 3rd generation) in the wild (H) and longevity-selected (D) model insect Acheta domesticus. We measured selected oxidative stress parameters, immunity, types of cell death, and DNA damage. Most of the results obtained in the 1st generation, e.g., catalase (CAT), total antioxidant capacity (TAC), heat shock proteins (HSP70), defensins, or apoptosis level, confirmed no significant toxicity of low doses of NDs. Interestingly, strain-specific differences were observed. D-strain crickets reduced autophagy, the number of ROS+ cells, and DNA damage. The effect can be a symptom of mobilization of the organism and stimulation of physiological defense mechanisms in long-living organisms. The 2nd-generation D-strain insects fed ND-spiked food at higher concentrations manifested a reduction in CAT, TAC, early apoptosis, and DNA damage, together with an increase in HSP70 and defensins. ROS+ cells and cells with reduced membrane potential and autophagy did not differ significantly from the control. H-strain insects revealed a higher number of ROS+ cells and cells with reduced membrane potential, decreased CAT activity, and early apoptosis. Elimination of NDs from the diet in the 3rd generation did not cause full recovery of the measured parameters. We noticed an increase in the concentration of HSP70 and defensins (H-strain) and a decrease in apoptosis (D-strain). However, the most visible increase was a significant increase in DNA damage, especially in H-strain individuals. The results suggest prolonged adverse effects of NDs on cellular functions, reaching beyond "contact time" with these particles. Unintentional and/or uncontrolled ND pollution of the environment poses a new challenge for all organisms inhabiting it, particularly during multigenerational exposure.

Towards understanding Cameraria ohridella (Lepidoptera: Gracillariidae) development: effects of microhabitat variability in naturally growing horse-chestnut tree canopy

Dwelling intensity of horse-chestnut miner (Cameraria ohridella) larvae in various leaves insolation and temperature was measured to determine whether this pest's development follows a predictable pattern or depends more on local microenvironment conditions. Mines growing on leaves of mature host plants (Aesculus hippocastanum L.) in their natural conditions were photographed for two consecutive generations of the pest and in two separated vegetation periods. Apart from meteorological data obtained from the nearest station, the temperature of intact and mined parts of sun-exposed and shaded leaf blades was measured at various daytimes throughout the experiment. Obtained sets of digital data were analysed and combined to model mine area growth as a function of degree-days sum by adopting of Verhulst logistic equation. We showed the predictive potential of our model based on experimental data, and it may be useful in the scheduling of pest control measures in natural conditions. Our analyses also revealed that despite significant differences in microenvironment conditions depending on mines' insolation, the horse-chestnut miner larvae could partially compensate for them and complete their development at similar endpoints expressed as the cumulative sum of degree-days. We conclude that computer-aided analysis of photographic documentation of leaf-miner larval growth followed by mathematical modelling offers a noninvasive, reliable, and inexpensive alternative for monitoring local leaf-miners populations.

Energy reserves, oxidative stress and development traits of Spodoptera exigua Hübner individuals from cadmium strain

Cadmium as a common environmental stressor may exert highly toxic effects on herbivorous insects. The question was whether possible elevation of an oxidative stress and imbalance of energetic reserves in insects may depend on developmental stage, sex and insect population's multigenerational history of exposure to cadmium. So, the aim of this study was to compare of the development traits, total antioxidant capacity, lipid peroxidation, RSSR to RSH ratio and the concentration of carbohydrates, glycogen, lipids and proteins in whole individuals (larvae or pupae) of Spodoptera exigua originating from two strains: control and selected over 120 generations with sublethal metal concentration (44 Cd mg per dry weight of diet). Generally, the increase of the protein, carbohydrates, glycogen concentration and lipid peroxidation decrease with age of the larvae were found. Revealed cases of a higher mobilisation of carbohydrates and proteins, and changes in total antioxidant capacity or lipid peroxidation, in individuals being under metal exposure, occurred in strain-depended mode. Short-term Cd exposure effect was connected with possible higher engagement of proteins and glycogen in detoxification processes, but also higher concentration of lipid peroxidation. In turn, for long-term Cd exposure effect lower lipids concentration and higher thiols usage seemed to be more specific.

Autophagy: a necessary defense against extreme cadmium intoxication in a multigenerational 2D experiment

Autophagy is a natural process that aims to eliminate malfunctioning cell parts, organelles or molecules under physiological conditions. It is also induced in response to infection, starvation or oxidative stress to provide energy in case of an energy deficit. The aim of this 2-dimensional study was to test if, and if so, how, this process depends on the concentration of cadmium in food (with Cd concentrations from 0 to 352 μg of Cd per g of food (dry weight)-D1 dimension) and the history of selection pressure (160 vs 20 generations of exposure to Cd-D2 dimension). For the study, the 5th instar larvae of a unique strain of the moth Spodoptera exigua that was selected for cadmium tolerance for 160 generations (44 μg of Cd per g of food (dry weight)), as well as 20-generation (11, 22 and 44 μg of Cd per g of food (dry weight)) and control strains, were used. Autophagy intensity was measured by means of flow cytometry and compared with life history parameters: survivability and duration of the 3rd larval stage. The highest values of autophagy markers were found in the groups exposed to the highest Cd concentration and corresponded (with a significant correlation coefficient) to an increased development duration or decreased survivorship in the respective groups. In conclusion, autophagy is probably initiated only if any other defense mechanisms, e.g., antioxidative mechanisms, are not efficient. Moreover, in individuals from pre-exposed populations, the intensity of autophagy is lower.

DNA damage in Spodoptera exigua after multigenerational cadmium exposure - A trade-off between genome stability and adaptation

Human activity is a serious cause of extensive changes in the environment and a constant reason for the emergence of new stress factors. Thus, to survive and reproduce, organisms must constantly implement a program of adaptation to continuously changing conditions. The research presented here is focused on tracking slow changes occurring in Spodoptera exigua (Lepidoptera: Noctuidae) caused by multigenerational exposure to sub-lethal cadmium doses. The insects received food containing cadmium at concentrations of 5, 11, 22 and 44 μg per g of dry mass of food. The level of DNA stability was monitored by a comet assay in subsequent generations up to the 36th generation. In the first three generations, the level of DNA damage was high, especially in the groups receiving higher doses of cadmium in the diet. In the fourth generation, a significant reduction in the level of DNA damage was observed, which could indicate that the desired stability of the genome was achieved. Surprisingly, however, in subsequent generations, an alternating increase and decrease was found in DNA stability. The observed cycles of changing DNA stability were longer lasting in insects consuming food with a lower Cd content. Thus, a transient reduction in genome stability can be perceived as an opportunity to increase the number of genotypes that undergo selection. This phenomenon occurs faster if the severity of the stress factor is high but is low enough to allow the population to survive.

Consequences of rapid development owing to cohort splitting: just how costly is it to hurry?

In cohort splitting, diverging sub-cohorts may show substantial differences in their growth and developmental rates. Although in the past, causes and adaptive value of cohort splitting were studied in detail, individual-level consequences of cohort splitting are still rather overlooked. Life history theory predicts that considerably increased growth and developmental rates should be traded off against other costly life history traits. However, it is not clear whether one should expect such associations in adaptive developmental plasticity scenarios, because natural selection might have promoted genotypes that mitigate those potential costs of rapid development. To address these contrasting propositions, we assessed life history traits in the wolf spider Pardosa agrestis, both collected from natural habitat and reared in laboratory. We found that some traits are negatively associated with developmental rates in spiders collected from the wild, but these associations were relaxed to a considerable extent in laboratory-reared specimens. In general, we observed no consistent trend for the presence of developmental costs, although some results might suggest higher relative fecundity costs in rapidly developing females. Our study provides a detailed approach to the understanding of individual-level consequences of cohort splitting, and to the associations between key life history traits in adaptive developmental plasticity scenarios.

Freshwater alien species Physella acuta (Draparnaud, 1805) - A possible model for bioaccumulation of heavy metals

In this study we focused on Physella acuta, an alien snail species in order to determine their ability of bioaccumulation of heavy metals in their shells, bodies, the difference in accumulation in relation to age classes, and the influence of ecological variables on the community composition and density. On the basis of the results of ecological, toxicological, and experimental analyses we aimed to study the potential invasive features of P. acuta in comparision with the native species Stagnicola palustris. The content of Cu and Zn in the substratum and ammonia in the water was strongly related to the patterns of distribution of P. acuta. The content of Cd, Pb, and Cu in the shell fraction was always significantly lower than in the body fraction. A comparison of accumulation with respect to the size classes of P. acuta indicated that the lowest metal concentration in the body was typical for the largest individuals, except for Zn. Metal content in the bodies of the native species did not differ from the content measured in their analogous group of the largest individuals of P. acuta. The lowest value of bioaccumulation factor (BAF) was found for the large class of specimens of this species for each metal. A distinct decrease in the value of BAF in relation to the size of snails was found for cadmium. A 100% hatching success found in masses collected from pond confirmed the high reproductive potential of P. acuta which can be a factor that promotes its invasive features following its ability to occur in very high densities, but not necessarily the ability of metal accumulation in the body. Physella acuta can be used as a model organism in the studies on the accumulation of heavy metals however, the extend of accumulation can differ among the age classes. Because of the high tolerance of P. acuta to heavy metal pollution, in the future this species can be found in significantly polluted habitats, inhabiting free ecological niches, and occurring in high densities in snail communities.

Protective role of zinc in Spodoptera exigua larvae under 135-generational cadmium exposure

The aim of this study was to investigate whether zinc supplementation modulates cadmium toxicity in the beet armyworm Spodoptera exigua selected for 135 generations towards cadmium tolerance. To achieve this, larvae originating from three laboratory populations of S. exigua (control strain - C; cadmium-intoxicated for 135 generations strain - Cd, and control strain intoxicated with Cd for 1 generation - CCd) were additionally exposed to zinc in three concentrations (Zn1, 400 μg Zn·g^-1 dry mass of food; Zn2; 200 μg Zn·g^-1 dry mass of food; Zn3, 100 μg Zn·g^-1 dry mass of food). As the markers of toxicity, a life history traits (the duration of L4 and L5 stages), cellular (DNA damage indices) and biochemical parameters (ADP/ATP ratio and ATP and HSP70 concentrations) were chosen. The duration of larval stages of Zn supplemented larvae was prolonged, while cellular and biochemical indicators, in general, appeared to be lower in comparison to the insects from respective reference groups in each laboratory populations. Moreover, the range of the differences depended on zinc concentration in food. We can suspect that zinc supplementation contributed to the protection of S. exigua individuals against negative effects of cadmium intoxication, probably at the cost of growth rate. Significant differences in the response pattern between insects from different laboratory populations indicate that the influence of additional stress factors is dependent on the overall condition of animals and their previous adaptation to other stressors.

Microevolution or wide tolerance? Level of stress proteins in the beet armyworm Spodoptera eqigua hübner (Lepidoptera: Noctuidae) exposed to cadmium for over 150 generations

The aim of this study was to investigate whether the cadmium tolerance developed in the beet armyworm Spodoptera exigua selected for over 150 generations may be related to synthesis of the stress proteins metallothioneins (Mts) and 70 kDa heat shock proteins (HSP70). To achieve this, six S. exigua strains (control, k), 150-generation Cd exposure strain (cd), and four 18-generation Cd exposure strains differing in Cd concentration (cd44, cd22, cd11, cd5) were reared. Stress protein level was measured in the midgut of the 5th larval stage after 1-6, 12 and 18 generations. Cd contents was measured in the pupae. Unlike Cd concentration, which depended on metal contents in food but was not generation-dependent, the pattern of Mts and HSP70 concentrations changed in experimental strains from generation to generation. Stress protein levels in the insects exposed to the highest Cd concentration (the same as in the 150-generation Cd exposure strain), initially higher than in the control strain, after the 12th generation did not differ from the level measured in the control strains. It seems therefore that stress proteins play a protective role in insects of lower tolerance to cadmium. The tolerance developed during multigenerational exposure probably relies on mechanisms other than Mt and HSP70 synthesis.

Immune response of juvenile common carp (Cyprinus carpio L.) exposed to a mixture of sewage chemicals

Pharmaceuticals and household chemicals are important components of municipal sewage. Many of them are biologically active, disrupting not only hormonal regulation of aquatic animals but also, indirectly, disturbing their immunological protection. In the environment, chemicals rarely act as individual substances, but as elements of mixtures. Therefore, the aim of this study was to check whether the acute laboratory exposure of common carp juveniles to a mixture of ibuprofen, sodium dodecyl sulphate (SDS), dimethyl sulfoxide (DMSO) and 17 α-ethynylestradiol in increasing concentrations, modifies the levels of innate immunity (lysozyme, C-reactive protein) as well as general stress (metallothioneins, heat shock proteins HSP70) markers in brain, liver, gills, spleen and mucus. The levels of the markers were measured by an immunodetection technique. Not only do the pharmaceuticals and household chemicals impair immunological reactions of young carp in various tissues but also do that in a concentration-dependent manner in the liver, gills, spleen and mucus. This has a very important implication, since it may result in higher sensitivity of young fish to pathogens due to energy allocation to defence processes. The comparisons of the pattern of stress reactions in the studied organ samples indicated that mucus appeared to be a good, non-invasive material for monitoring of environmental state and fish conditions.

Sterile Capsule-Egg Cocoon Covering Constitutes an Antibacterial Barrier for Spider Parasteatoda tepidariorum Embryos

Coexistence of organisms and pathogens has resulted in the evolution of efficient antimicrobial defense, especially at the embryonic stage. This investigation aimed to substantiate the hypothesis that the layers of silk in a spider cocoon play a role in the immunity of the embryos against microorganisms present in the external environment. A two-step interdisciplinary attempt has been made. First, the eggs and empty cocoons of the spider Parasteatoda tepidariorum were incubated on lysogeny broth agar media for 3 d. In the samples of eggs, no growth of bacteria was detected. This indicated that the eggs inside cocoons were sterile. Therefore, in the second step, the cocoons and egg surface were analyzed using SEM, TEM, and LM. The obtained images demonstrated that both inner and outer layers of the silk are built of threads of the same diameter, set in an irregular manner, and randomly clustered into groups. The threads in the outer layer were packed more densely than in the inner one. TEM analysis revealed threads of two types of fibrils and their arrangement. The resultant thread tangle of the cocoon, possibly correlated with the ultrastructure of the fibers, seems to be an example of a structure-function relationship playing a crucial ecoimmunological role in spider embryonic development.

Cross tolerance in beet armyworm: long-term selection by cadmium broadens tolerance to other stressors

Long lasting exposure of animals to stressing factor may lead to the selection of population able to cope with the stressor at lower cost than unexposed individuals. The aim of this study was to assess whether 130-generational selection of a beet armyworm to cadmium in food might have induced tolerance also to other stressors. The potential tolerance was assessed by means of unspecific stress markers: HSP70 concentration, DNA damage level, and energy budget indices in L5 larval instars of beet armyworm. The animals originated from Cd-exposed and control strains exposed additionally in a short-term experiment to high/low temperature or pesticide-spinosad. The application of the additional stressors caused, in general, an increase in the levels of studied parameters, in a strain-dependent manner. The most significant increase was found in HSP70 level in the individuals from the Cd-strain exposed to various spinosad concentration. Therefore, multigenerational contact with cadmium caused several changes that enable the insect to survive under a chronic stress, preparing the organism to the contact with an additional, new stressor. This relationship may be described as a sort of cross tolerance. This may, possibly, increase the probability of population survivorship and, at the same time, decrease the efficiency of pesticide-based plant protection efforts.

Phenotypic Plasticity, Epigenetic or Genetic Modifications in Relation to the Duration of Cd-Exposure within a Microevolution Time Range in the Beet Armyworm

In the case of the pests inhabiting metal polluted or fields where the use of pesticides is common, a natural selection of resistant individuals can occur. This may pose serious problems for humans, agriculture, as well as the economies of many countries. In this study, the hypothesis that multigenerational (120 generations) exposure to cadmium of a beet armyworm population could be a selecting factor toward a more efficient DNA protection was verified. The hemocytes of individuals from two culture strains (control and Cd-exposed) were treated with H2O2 (a DNA-damaging agent) or PBS (reference). The level of DNA damage was assessed using the Comet assay immediately and 5, 15 and 30 min. after the treatment. The immediate result of the contact with H2O2 was that the level of DNA damage in the hemocytes of the insects from both strains increased significantly. However, in the cells of the Cd-exposed individuals, the level of DNA damage decreased over time, while in the cells from the control insects it remained at the same level with no evidence of repair. These results suggest that efficient defense mechanisms may exist in the cells of insects that have prolonged contact with cadmium. Some evolutionary and trade-off aspects of the phenomenon are discussed. In a wider context, comparing the results obtained in the laboratory with field studies may be beneficial for understanding basic mechanisms of the resistance of an organism. To summarize, the high potential for the repair of DNA damage that was observed in the insects from the cadmium strain may confirm the hypothesis that multigenerational exposure to that metal may possibly contribute to the selection of insects that have a wider tolerance to oxidative stress. However, our investigations of polymorphism using AFLP did not reveal differences between the two main insect strains.

Modulation of the response to stress factors of Xerolycosa nemoralis (Lycosidae) spiders living in contaminated environments

The rapid development of industry has caused widespread pollution in the environment, which has a negative impact on living organisms. Spiders belong to the group of animals that can exist in these anthropogenically changed areas. This is probably due to the development of tolerance mechanisms in these organisms. The impact of long-term pollution on the development of the pre-adaptation to various stress factors in spiders is unknown. In this paper, we show that living in polluted areas affects the modulation of the response to other stress factors through changes in the Hsp70 level. We observed a positive reaction to heat shock in all of the experimental groups, which was expressed by an increase in Hsp70 synthesis compared to the control. The analysis of the protein level, which was a manifestation of the pre-adaptation, was dependent on the degree of pollution on the study sites, the sexes and the type of bioassay that was performed. Our results demonstrate the reaction of spiders living in contaminated areas to the presence of additional stressors. We anticipate our results will be another voice in the discussion on the use of Hsp70 as a stress biomarker in environmental biomonitoring.

X-ray microtomography for imaging of developing spiders inside egg cocoons

Embryogenesis is especially sensitive to external factors. The changes in its course are often used as biomarkers of environmental impact. Since spider embryogenesis takes place inside cocoons, it is crucial to find a reliable tool to analyze this developmental phase with no intrusion into the cocoons. The aim of this study was to verify the efficacy of X-ray microtomography for non-invasive analysis of embryonic morphology and egg quantity in the cocoons of Xerolycosa nemoralis and Agelena labyrinthica from polluted and reference sites. X-ray microtomography slice images as well as 3D images and animations obtained from digital visualization of those slides were used to study the morphology of embryos and egg arrangement in the cocoons. Any disorders in embryogenesis or malformation of embryos in relation to site of origin have not been found, but inside an egg cocoon of X. nemoralis from the polluted site embryos differing form each other by one developmental stage were identified. Egg calculation revealed a K- reproductive strategy of X. nemoralis from polluted sites. Finally, future prospects and benefits, and weaknessess of this method for the study of spider cocoons have presented.

Apoptotic and necrotic changes in the midgut glands of the wolf spider Xerolycosa nemoralis (Lycosidae) in response to starvation and dimethoate exposure

In the present study, the intensity of degenerative changes (apoptosis, necrosis) in the cells of the midgut glands of male and female wolf spiders, Xerolycosa nemoralis (Lycosidae), exposed to natural (starvation) and anthropogenic (the organophosphorous pesticide dimethoate) stressors under laboratory conditions were compared. The spiders were collected from two differentially polluted sites, both located in southern Poland: Katowice-Welnowiec, which is heavily polluted with metals, and Pilica, the reference site. Starvation and dimethoate treatment resulted in enhancement of apoptotic and necrotic changes in the midgut glands of the spiders. The frequency of degenerative changes in starving individuals was twice as high as in the specimens intoxicated with dimethoate. The percentage of apoptotic and necrotic cells was higher in starving males than in starving females. A high intensity of necrotic changes, together with increased Cas-3 like activity and a greater percentage of cells with depolarized mitochondria, were typical of starving males from the polluted site. The cell death indices observed in females depended more strongly on the type of stressor than on previous preexposure to pollutants.

Antioxidative responses in females and males of the spider Xerolycosa nemoralis (Lycosidae) exposed to natural and anthropogenic stressors

The aim of this study was to assess the intensity of enzymatic antioxidative parameters [i.e., superoxide dismutase (SOD), catalase (CAT), and the glutathione peroxidases each selene dependent, GPOX or selene independent, including GSTPx, glutathione S-transferase, and GST] and non-enzymatic antioxidative parameters [i.e., glutathione total (GSH-t), the heat shock proteins of Hsp70, and metallothioneins (Mt)] in the midgut glands of female and male wolf spiders Xerolycosa nemoralis (Lycosidae) exposed to natural stressors (i.e., heat shock and starvation) and anthropogenic stressors (i.e., the organophosphorous pesticide dimethoate) under laboratory conditions. The spiders were collected from two differentially polluted sites both localized in southern Poland: Olkusz, which is heavily polluted with metals, and Pilica, the reference site. In response to the stressing factors, increases in Hsp70 levels, in the concentrations of total glutathione and in the activity levels of glutathione-dependent enzymes (GPOX, GSTPx, and GST) were found in the midgut glands of males. In the females, high levels of activity of CAT and SOD were revealed, as well as an increased percentage of Mt-positive cells. Preexposed females, in comparison to the individuals from the reference site, responded with increased SOD activity, irrespective of the stressing factor. In contrast, the changes in the antioxidative parameters in the midgut glands of male X. nemoralis seem to reflect a short-term reaction to the applied stressors and do not confirm the effects of long-term selection in a polluted environment.

The reproductive potential of the spiders Agelena labyrinthica and Xerolycosa nemoralis from areas contaminated with metals

Spiders successfully colonize industrially contaminated environments and maintain relatively stable populations. The aim of this study was to explain the reproductive strategies of two spider species, Xerolycosa nemoralis (an actively hunting, sit-and-pursue predator) and Agelena labyrinthica (a web-building, sit-and-wait predator), between contaminated and uncontaminated sites. Spiders were collected from a reference site (Pilica) and two contaminated sites (Olkusz and Welnowiec). The amount of energy allocated to the eggs and the number of eggs and hatchlings as well as the hatching success were compared. Wolf spiders from the contaminated sites produced fewer but relatively energy-rich eggs, whereas web-building spiders invested their energy in the production of a higher number of less energy-rich eggs. The comparisons of the hatching percentages suggested that in the contaminated habitats, X. nemoralis achieve a hatching success similar to or higher than that of the reference population at Pilica. A. labyrinthica in the contaminated sites invested a larger amount of energy in eggs than at the reference site, but the hatching success found for this species in the contaminated areas was lower than that found at the reference site.

Quantitative immunodetection of metallothioneins in relation to metals concentration in spiders from variously polluted areas

Spiders inhabiting post industrial environments, such as waste heaps or ore-bearing areas, are exposed to high concentrations of metals, accumulated in the body of their prey and transferred along food chains. Therefore spiders are pressed to develop metal-neutralization strategies. Low-molecular, multifunction proteins: metallothioneins (MTs), often postulated as biomarkers of metal exposure, are known to bind metals and thus protect organisms against their toxic effects. Yet the proteins are still not well recognized in spiders. The aim of this study was to assess, by immunodetection method, ELISA, the concentration of metallothioneins in adult females of three web building spider species: Araneus diadematus (Araneidae), Agelena labyrinthica (Agelenidae) and Linyphia triangularis (Linyphiidae) from three variously polluted areas in southern Poland: Olkusz, ore-bearing post industrial site; Katowice-WeŁnowiec: post metallurgic waste heap, Pilica: the reference, rural, area. The concentration of metallothioneins has been analyzed in relation to the metal concentration in spiders body. The study gives the evidence that metallothioneins are reliably detectable by means of ELISA technique. The analysis of results obtained shows a strong species-dependence of the MTs level. Positive correlations between MTs concentration and metal body burden (mainly Zn and Pb) were found. This suggests that the proteins play an important role in the neutralization and regulation of metal ions in spiders. The same correlation indicate the possibility to consider MTs in spiders as biomarkers of metal exposure and effects. However, the species specificity as well as metal characteristics should be taken under account.

Metallothioneins and energy budget indices in cadmium and copper exposed spiders Agelena labyrinthica in relation to their developmental stage, gender and origin

The aim of our studies was to explain the role of metallothioneins (MTs) in the neutralization of excessive amounts of metals (essential: copper (Cu) and toxic: cadmium (Cd)) and to describe the energy status in metal-exposed spiders Agelena labyrinthica in relation to its developmental stage, gender and origin. Juvenile, female and male spiders were collected from three variously polluted habitats, transferred to the laboratory and exposed to the metals in their diet. Cu and Cd accumulation in the body and exuviae, bioaccumulation factor, percentage of metallothionein positive cells, MT concentration, percentage of cells with depolarized mitochondria, ATP concentration and ADP/ATP ratio were measured and calculated. Cu appeared to be regulated and its excess is eliminated via, among others, the molting process, while Cd was rather accumulated by the spiders. The level of MTs increased significantly mainly in females exposed to both metals, irrespectively of the pollution degree of their site of origin, indicating a defensive role of the proteins. In general, even if both the MT level and the energy status indices were positively correlated with Cd and Cu concentrations in the spider body, the energy status of A. labyrinthica did not seem disturbed.

Oxidative stress in newly-hatched Chorthippus brunneus--the effects of zinc treatment during diapause, depending on the female's age and its origins

The responses of glutathione, glutathione S-transferases (GSTs), and catalase (CAT) were determined in 1-day-old larvae of Chorthippus brunneus Thunberg, 1815, a grasshopper exposed to zinc during diapause, from unpolluted (Pilica) or polluted (Olkusz, Szopienice) sites. The aim of the work was to search for differences among populations of the insects as a result of various multistress pressures in their habitats. The question of zinc toxicity in the context of energy allocation was also considered. Zinc caused a decrease in glutathione concentration in the body of zinc-treated larvae. Significant differences between control and zinc-treated groups were confirmed for young females' progeny from Pilica and Olkusz as well as old females' progeny from Olkusz. GSTs activity was generally not influenced by zinc. It is possible that GSTs were not the most important target of zinc action. On the contrary, the influence of zinc on CAT activity was found. The increase in CAT activity after zinc treatment was similar for all studied populations. An increase in CAT activity after zinc exposure seems to be the most universal reaction. CAT activity in zinc-treated grasshoppers may explain the mechanism of zinc toxicity based on reactive oxygen forms generation.

The effects of Aphis fabae infestation on the antioxidant response and heavy metal content in field grown Philadelphus coronarius plants

The purpose of this study was to explore a possible relationship between the soil availability of metals and their concentrations in various parts of Philadelphuscoronarius plants. Moreover, the possible impact of an aphid infestation on the contamination and antioxidant response of plants from the urban environment of Kraków and the reference rural area of Zagaje Stradowskie (southern Poland) was analyzed. The contents of the glutathione, proline, non-protein -SH groups, antioxidants, and phosphorous and the levels of guaiacol peroxidase and catalase activity in leaves and shoots either infested or not by the aphid Aphis fabae Scop., were measured. The potential bioavailability of metals (Cd; Cu; Ni; Pb; Zn) in the soil and their concentrations in P. coronarius plants originating from both sites were compared. The antioxidant responses were generally elevated in the plants in the polluted area. Such reactions were additionally changed by aphid infestation. Generally, the concentrations of metals in the HNO(3) and CaCl(2) extractants of the soils from two layers at the 0-20 and 20-40 cm depths from the polluted area were higher than in those from the reference area. Such differences were found for nickel and lead (in all examined extractants), zinc (in soil extractants from the layer at 20-40 cm) and cadmium (in HNO(3) extractants). Significant positive relationships between the lead concentrations in the soil and in the plants were found. In the parts of plants from the polluted area, higher concentrations of Pb and Zn (leaves and shoots) and Cd (shoots) were recorded. The shoots and leaves of plants infested with aphids had higher concentrations of Zn but lower Pb. Moreover, their leaves had higher contaminations of Cu and Ni. In conclusion, aphids affected not only the antioxidant response of the plants but also their contamination with metals, especially contamination of the leaves.

Hsp70 level in progeny of aging grasshoppers from variously polluted habitats and additionally exposed to zinc during diapause

The hsp70 level in the bodies of 1st instars of grasshoppers Chorthippus brunneus from unpolluted (Pilica) and polluted (Olkusz, Szopienice) sites and additionally exposed to various doses of zinc during diapause and embryonic development prior to hatching were measured by Western blotting. The main aim of our work was to assess the relationship between the age of female grasshoppers originating from variously polluted habitat and the hsp70 level in their progeny. Possible reasons for population variation in hsp70 levels were discussed. The hsp70 level in the offspring's body depended on the place of origin. The strongest expression of hsp70 was found in the bodies of larvae hatching from the eggs laid by young females from Pilica (reference site). In contrast, a low initial level of hsp70 in larvae from polluted sites, especially in young females' progeny, was observed. The application of zinc during diapause influenced the hsp70 level in grasshopper larvae; however, the direction of the changes depended on the insects' place of origin. In larvae from the reference site, and also (but to a lesser degree) from Olkusz, the increase in the hsp70 level after zinc treatment was most pronounced. Whereas in grasshoppers from Szopienice, zinc (in 100microg g(-1) dry weight of sand) did not change the hsp70 level, or (in 500microg g(-1) dry weight of sand) caused a reduction in hsp70. The differences may result from maternal effects; however, possible adaptation also cannot be excluded. To confirm this statement further studies are needed.

Cellular stress reactions assessed by gender and species in spiders from areas variously polluted with heavy metals

In the funnel web spider Agelena labyrinthica (Agelenidae; A. l.), sheet web spider Linyphia triangularis (Linyphiidae; L. t.) and wolf spider Xerolycosa nemoralis (Lycosidae; X. n.) from two differently polluted meadow sites in southern Poland, we studied the relations between antioxidant parameters (glutathione, GSH; glutathione peroxidases, GPOX, GSTPx; catalase, CAT; stress proteins-Hsp70, metallothioneins Mts), the intensity of apoptosis and necrosis, and heavy metal burdens of the midgut gland. Cellular reactions against stress caused by pollutants seemed to be sex-dependent. The concentrations of Zn and Cu in the midgut glands of male A. l. and X. n. were more than double that of the females, from both study sites. In male spiders from the heavily polluted site, both negative correlations (activity of caspase-3-like proteins vs Cu, Zn concentration; number of depolarized mitochondria vs Cu concentration) and positive correlations (number of necrotic cells vs Cu concentrations; activity of CAT vs Zn ) were noted. The defense of males against high metal content and its prooxidative effects is based mainly on GSH and CAT. In females the antioxidative reactions are species-specific and depend mainly on high peroxidase activity and on stress protein level. The increase in the number of apoptotic cells in the midgut gland of female spiders from the heavily polluted site suggests the defensive role of this process in maintaining the proper functioning of this organ.

Effects of zinc and female aging on nymphal life history in a grasshopper from polluted sites

Insect reproduction is influenced by various factors, including food quality and quantity, temperature, population density and female age. Contamination, including heavy metals, may disturb reproductive processes. The aim of this work was to assess interactions between effects of aging in female Chorthippus brunneus and environmental pollution on their reproduction measured in number of laid eggs. We also compared basic developmental parameters (number of hatchlings, body mass, embryonic developmental rate) in grasshopper nymphs additionally exposed to zinc during diapause. Aging grasshoppers from heavily polluted areas (Olkusz and Szopienice) lay significantly fewer eggs than insects from the reference site (Pilica). Zinc application caused the decrease in hatching success and duration of embryogenesis in insects from each site. This suggests a cumulative effect of female age, pollutants and additional stressing factors. The intensity of this process differed between populations. In insects from the reference site, it was shown in a moderate degree. In insects from Szopienice, an additional stressor exerted a weaker effect than in insects from Pilica. In grasshoppers from Olkusz, we found the strongest decrease of hatching percentage and increase in duration of embryogenesis after zinc intoxication. This may indicate that the population from Olkusz exists at the limit of its energetic abilities.

Short-term effects of dimethoate on metabolic responses in Chrysolina pardalina (Chrysomelidae) feeding on Berkheya coddii (Asteraceae), a hyper-accumulator of nickel

Berkheya coddii Roessler (Asteraceae) is a hyper-accumulator of nickel, which can be used in phytomining and phytoremediation. Chrysolina pardalina Fabricius (Chrysomelidae) is a phytophagous leaf beetle, which may be useful in controlling population levels of B. coddii after it has been introduced into a new habitat. The aim of this study was to investigate the response of C. pardalina to topical application of dimethoate. Data recorded included the activity of acetylcholinesterase (AChE), the concentration of glutathione (GSH), and the activity of selected enzymes connected with GSH metabolism. Assays were carried out several times during the first 24h after exposure to dimethoate. At the dosages used in this study, dimethoate was not as toxic as expected. AChE activity was significantly decreased 14 and 24h after application. GST activity was significantly decreased 24h after application. GSTPx activity was significantly decreased 2, 14 and 24h after application. GR activity was significantly increased 4h after application. GSH concentration was significantly increased 24h after application. Long-term exposure to high levels of nickel may have caused adaptive changes in the enzymes that enable C. pardalina to deal with other stressors, including organophosphate pesticides.

Zinc-induced DNA damage and the distribution of metals in the brain of grasshoppers by the comet assay and micro-PIXE

The distribution and concentration of selected elements by PIXE method and DNA damage using comet assay in brains of 1st instars of grasshoppers Chorthippus brunneus from unpolluted (Pilica) and polluted (Olkusz) site, additionally exposed to various doses of zinc during diapause or after hatching, were measured. We tried to assess the degree of possible pre-adaptation of the insects to heavy metals and evaluate the utility of these parameters in estimation of insect exposure to industrial pollutants. Additionally, the mechanism of zinc toxicity for grasshopper brains was discussed. We observed the correlation between experimental zinc dose, zinc contents in the brain and DNA damage in neuroblasts, but only in groups exposed to lower zinc concentration. For higher zinc concentration the amount of the metal in brain and DNA damage remained at the control level. Some site-related differences in DNA damage between grasshoppers from Pilica and Olkusz were observed during short-term exposure (after hatching). Significant increase in the calcium contents in the brain, proportional to zinc concentration in sand, was also observed, especially in the offsprings from Olkusz. The results may be the basis for further searching for molecular mechanisms of defense against heavy metals in insects living in polluted habitats.

Effects of dimethoate on spiders from metal pollution gradient

In this study, an attempt has been made to assess whether a chronic exposure to metals in habitats under a strong industrial pressure might have equipped spiders with biochemical defensive mechanisms enabling them to survive an additional chemical stress. To check this, non-web-building wolf spiders Pardosa lugubris (Lycosidae) and funnel web Agelena labyrinthica (Agelenidae) were collected at five variously polluted meadows and, under laboratory conditions, intoxicated with either single or multiple dose of dimethoate (OP pesticide). Then the activities of detoxifying (carboxylesterase: CarE, glutathione S-transferase: GST), antioxidative (selene-dependent and selene-independent glutathione peroxidases: GPOX and GSTPx) enzymes as well as acetylcholinesterase as a biomarker of exposure to OP pesticides were measured. In web-building A. labyrinthica, even a single application of the pesticide caused the inhibition of CarE, GSTPx and GPOX in individuals from less polluted sites and AChE and GST in specimens pre-exposed to high metal concentrations. Multiple intoxication, irrespectively of the site, caused significant, in comparison to controls, decrease in CarE, AChE and GSTPx activities. Actively hunting P. lugubris seem more resistant to acute pesticide intoxication, since the spiders from each site had a constant level of GST and AChE. In individuals of this species from heavily polluted sites, the inhibition caused by multiple intoxication with dimethoate was stated only for glutathione peroxidases.

Joint effects of dimethoate and heavy metals on metabolic responses in a grasshopper (Chorthippus brunneus) from a heavy metals pollution gradient

We studied how an exposure to an additional stressing factor-dimethoate, might affect detoxifying ability of grasshoppers collected at 5 meadow sites located along a heavy metal pollution gradient. Activities of esterases and enzymes linked with glutathione (GSH) metabolism were assayed 24 h after topical treatment with 0.32 microg dimethoate per insect. Inhibition of acetylcholinesterase (AChE) reaches nearly 50% of the value stated in untreated insects, without significant site-dependent differences. The pesticide also caused a significant decrease in activities of glutathione peroxidase (GPx) followed by a decrease in GSH levels in grasshoppers from all assayed groups, demonstrating high sensitivity of glutathione-dependent metabolism to the additional stressing factor. In the case of glutathione reductase (GR) and carboxylesterases (CarE) the fall of activity was shown especially in insects from less polluted meadows and the reference site. Glutathione reductase (GR) activity in individuals treated with dimethoate did not decrease only in insects from the most contaminated site I. This might suggest the trade-off mechanisms adapting grasshoppers to life in seriously polluted environments.

Relations between metals (Zn, Pb, Cd and Cu) and glutathione-dependent detoxifying enzymes in spiders from a heavy metal pollution gradient

We studied the relations between glutathione-dependent detoxifying enzymes and heavy metal burdens in the web-building spider Agelena labyrinthica (Agelenidae) and the wolf spider Pardosa lugubris (Lycosidae) from five meadow sites along a heavy metal pollution gradient. We assayed the activity of glutathione-S-transferase (GST) and glutathione peroxidases (GPOX, GSTPx), and glutathione (GSH) levels in both sexes. Except for GSH vs Pb content, we found significant correlations between GPOX and GSTPx activity and metal concentrations in females of A. labyrinthica. The highest activity of these enzymes measured in the web-building spiders was found in the individuals from the most polluted sites. In P. lugubris males significant correlations were found between GST and Pb and Zn concentrations, and between GPOX and GSTPx and the concentration of Cu. GST activity was higher in males collected from less polluted areas. Thus, detoxifying strategies against pollutants seemed to be sex-dependent. Actively hunting spiders had higher metal concentrations, maintaining lower activity of detoxifying enzymes and a lower glutathione level.

Profiles of enzymatic activity in earthworms from zinc, lead and cadmium polluted areas near Olkusz (Poland)

The aim of the study was to determine whether there are signs of adaptation of soil fauna to a gradient of heavy metal contamination. Earthworms Aporrectodea caliginosa, Lumbricus terrestris and Eisenia fetida were collected during the spring and summer of 2000 and 2001 from meadow sites situated between 2 and 32 km from the Bukowno-Olkusz complex of zinc-lead ore mines and smelters. The heavy metal content in the soil near smelters reaches 10,500 mg/kg (d.w.) for Zn, 2600 mg/kg for Pb and 81.9 mg/kg for Cd. The sites differ with respect to species composition of earthworm community, with A. caliginosa being dominant. Complete data was obtained only for A. caliginosa, since other species were not abundant at all investigated sites during the whole period of investigation. The body burdens of Zn, Pb, Cd and Cu in A. caliginosa reached 1500, 100, 220 and 10 microg/g, respectively, in the vicinity of the smelter (2-4 km), and decreased to 400, 2, 36 and 6 microg/g at the most distant site (32 km). Cadmium and lead content was significantly elevated in the whole body of L. terrestris collected at the site 2.5 km distant from the smelters when compared to more distant sites, while in E. fetida only the body burden of cadmium was elevated at the nearest site compared to the next site of transect. Activities of glutathione peroxidase (GPX; EC 1.11.1.9) against hydrogen peroxide (H2O2) or cumene hydroperoxide (cumOOH), glutathione reductase (GR; EC 1.6.4.2), glutathione S-transferase (GST; EC 2.5.1.18) and catalase (CAT; EC 1.11.1.6) were assayed in postmitochondrial supernatant obtained from whole body homogenates. Seasonal and annual variations of enzyme activity were reflected by higher GPX activity in the late summer of 2001 in comparison with the spring and summer of 2000. This may reflect severe drought in the spring and summer of 2000. The activity of both GPX isozymes, GR and GST in A. caliginosa and L. terrestris increased with increasing distance from the smelters and reached maximum at sites III and IV (4 and 8 km from the smelters, respectively) and then it decreased in the animals from site V (32 km). These may be the effects of antagonism between the enzyme inducing and enzyme inhibiting action of smelter emissions, a phenomenon known as a hormetic effect. It is postulated here that this effect is of diagnostic value for metal pollution biomonitoring.

Activity of carboxylesterase and glutathione S-transferase in different life-stages of carabid beetle (Poecilus cupreus) exposed to toxic metal concentrations

Among the cytoplasmatic enzymes responsible for neutralization of organic xenobiotics, carboxylesterases (CarE) and glutathione S-transferases (GST) play important roles. Our study tested to what extent dietary Zn or Cd could modify the activity of CarE and GST at different life-stages of the carabid beetle Poecilus cupreus. Treatment and stage effects generally were statistically significant. For CarE activity in the beetles exposed to cadmium, only treatment was a significant factor. In all cases, the interaction between studied factors was statistically significant, implying that the physiological condition of the animals may enhance or reduce enzyme activity. We also observed differences between animals treated with cadmium and zinc in the pattern of enzyme activity, and a difference in GST activity measured with two different substrates. Our results confirmed that in studying enzyme activity under metal stress one should consider the animal's life-stage and sex.