Adaptive reactions of algal populations to exposure to toxic substances

The adaptative reactions of alga populations to the toxic effect have been investigated by the functional triad method. The role of phenotypic and genotypic adaptation and the dynamics of their correlation during the alga adaptation to the toxic media has been revealed.     

Transgenerational health effects of in utero exposure to economic hardship: Evidence from preindustrial Southern Norway

We studied whether in utero exposure to economic hardship during a grandmother’s pregnancy has a transgenerational effect on her grandchildren's health condition. We used an individual-level three-generation data set covering people born between 1734 and 1840 in the municipality of Rendalen in Norway. We found a culling effect in which grandchildren whose grandmothers gave birth in years of economic hardship lived approximately ten years longer than grandchildren whose mothers were born in years of economic well-being. This impact was only observed among the grandmothers who belong to the lowest social classes. Our results also showed that in higher social classes, economic hardship during a grandmother’s pregnancy deteriorated her grandchildren’s health by “scarring” the mother’s health.     

Transgenerational effects of stress exposure on offspring phenotypes in apomictic dandelion

Heritable epigenetic modulation of gene expression is a candidate mechanism to explain parental environmental effects on offspring phenotypes, but current evidence for environment-induced epigenetic changes that persist in offspring generations is scarce. In apomictic dandelions, exposure to various stresses was previously shown to heritably alter DNA methylation patterns. In this study we explore whether these induced changes are accompanied by heritable effects on offspring phenotypes. We observed effects of parental jasmonic acid treatment on offspring specific leaf area and on offspring interaction with a generalist herbivore; and of parental nutrient stress on offspring root-shoot biomass ratio, tissue P-content and leaf morphology. Some of the effects appeared to enhance offspring ability to cope with the same stresses that their parents experienced. Effects differed between apomictic genotypes and were not always consistently observed between different experiments, especially in the case of parental nutrient stress. While this context-dependency of the effects remains to be further clarified, the total set of results provides evidence for the existence of transgenerational effects in apomictic dandelions. Zebularine treatment affected the within-generation response to nutrient stress, pointing at a role of DNA methylation in phenotypic plasticity to nutrient environments. This study shows that stress exposure in apomictic dandelions can cause transgenerational phenotypic effects, in addition to previously demonstrated transgenerational DNA methylation effects.     

Linking exposure to environmental pollutants with biological effects

Exposure to ambient air pollution has been associated with cancer. Ambient air contains a complex mixture of toxics, including particulate matter (PM) and benzene. Carcinogenic effects of PM may relate both to the content of PAH and to oxidative DNA damage generated by transition metals, benzene, metabolism and inflammation. By means of personal monitoring and biomarkers of internal dose, biologically effective dose and susceptibility, it should be possible to characterize individual exposure and identify air pollution sources with relevant biological effects. In a series of studies, individual exposure to PM(2.5), nitrogen dioxide (NO(2)) and benzene has been measured in groups of 40-50 subjects. Measured biomarkers included 1-hydroxypyrene, benzene metabolites (phenylmercapturic acid (PMA) and trans-trans-muconic acid (ttMA)), 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) in urine, DNA strand breaks, base oxidation, 8-oxodG and PAH bulky adducts in lymphocytes, markers of oxidative stress in plasma and genotypes of glutathione transferases (GSTs) and NADPH:quinone reductase (NQO1). With respect to benzene, the main result indicates that DNA base oxidation is correlated with PMA excretion. With respect to exposure to PM, biomarkers of oxidative damage showed significant positive association with the individual exposure. Thus, 8-oxodG in lymphocyte DNA and markers of oxidative damage to lipids and protein in plasma associated with PM(2.5) exposure. Several types of DNA damage showed seasonal variation. PAH adduct levels, DNA strand breaks and 8-oxodG in lymphocytes increased significantly in the summer period, requiring control of confounders. Similar seasonal effects on strand breaks and expression of the relevant DNA repair genes ERCC1 and OGG1 have been reported.In the present setting, biological effects of air pollutants appear mainly related to oxidative stress via personal exposure and not to urban background levels. Future developments include personal time-resolved monitors for exposure to ultrafine PM and PM(2.5,) use of GPS, as well as genomics and proteomics based biomarkers.     

Adverse reproductive outcomes from exposure to environmental mutagens.

The effect of environmental pollution on reproductive outcomes has been studied in the research project 'Teplice Program' analyzing the impact of air pollution on human health. Genotoxicity of urban air particles <10 microm (PM10) in in vitro system was determined by the analysis of DNA adducts. The highest DNA binding activity was observed in aromatic fraction, identifying DNA adducts of carcinogenic polycyclic aromatic hydrocarbons (PAHs) presumably diolepoxide-derived from: 9-hydroxybenzo[a]pyrene (9-OH-B[a]P), benzo[a]pyrene-r-7,-dihydrodiol-t-9,10-epoxide[+] (anti-BPDE), benzo[b]fluoranthene (B[b]F), chrysene (CHRY), benz[a]antracene (B[a]A), indeno[1,2,3-cd]pyrene (I[cd]P). Reproductive studies were conducted in both females and males. A study of the effects of PM10 exposure on pregnancy outcomes found the relationship between the intrauterine growth retardation (IUGR) and PM10 levels over 40 microg/m(3) in the first gestational month (Odds Ratio for 40-50 microg/m(3)50 microg/m(3)=1.9). Selected biomarkers were analyzed in venous blood, cord blood (chromosomal aberrations, comet assay) and placenta (DNA adducts, genetic polymorphisms of GSTM1 and NAT2 genotypes) of women enrolled in a nested case-control study. DNA adduct levels were higher in polluted vs. control districts, in smoking vs. nonsmoking mothers, and in GSTM1 null genotype, which was more pronounced in polluted district. No effect of air pollution was observed by cytogenetic analysis of chromosomal aberrations or by comet assay. The reproductive development of young men was followed by measures of semen quality, adjusted for ambient SO(2) exposure. The analysis identified significant associations with air pollution for <13% morphologically normal sperm, <29% sperm with normal head shape, <24% motile sperm. Analysis of aneuploidy in human sperm by FISH showed, aneuploidy YY8 was associated with season of heaviest air pollution. These findings are suggestive for an influence of air pollution on YY8 disomy. All these results indicate that air pollution may increase DNA damage in human population, which may be even higher for susceptible groups. Biomarkers of exposure (DNA adducts) and susceptibility (GSTM1 and NAT2) may indicate the risk of presumable low environmental exposure. Pregnancy outcome and semen studies imply that relatively low air pollution (higher than 40 microg PM10/m(3)) can significantly increase the adverse reproductive outcomes affecting both genders.     

Production of extracellular polymeric substances from Rhodopseudomonas acidophila in the presence of toxic substances

A hydrogen-producing photosynthetic bacteria strain, Rhodopseudomonas acidophila, was used to investigate the production of extracellular polymeric substances (EPS) in the presence of toxic substances and the effect of toxicants on bacterial surface characteristics. Addition of the toxic substances including Cu(II), Cr(VI), Cd(II) and 2,4-dichlorophenol (2,4-DCP) stimulated the production of EPS but reduced the cell dry weight. At concentrations of 30 mg l⁻¹ Cu(II), 40 mg l⁻¹ Cr(VI), 5 mg l⁻¹ Cd(II) and 100 mg l⁻¹ 2,4-DCP, the EPS content increased by 5.5, 2.5, 4.0 and 1.4 times, respectively, than the control. These toxic substances also greatly influenced the proteins/carbohydrates ratio of EPS. The ratios in the presence of toxic substances were always higher than that of control. Furthermore, under toxic conditions, the increase in the protein content far exceeded than that of others in EPS, suggesting that extracellular proteins could protect cells against toxic substances. The toxic substances significantly changed the surface characteristics and flocculation ability of R. acidophila, such as surface energy, relative hydrophobicity and free energy of adhesion.     

Transgenerational effects of global environmental change: long-term CO2 and nitrogen treatments influence offspring growth response to elevated CO2

Global environmental changes can have immediate impacts on plant growth, physiology, and phenology. Long-term effects that are only observable after one or more generations are also likely to occur. These transgenerational effects can result either from maternal environmental effects or from evolutionary responses to novel selection pressures and are important because they may alter the ultimate ecological impact of the environmental change. Here, we show that transgenerational effects of atmospheric carbon dioxide (CO₂) and soil nitrogen (N) treatments influence the magnitude of plant growth responses to elevated CO₂ (eCO₂). We collected seeds from Lupinus perennis, Poa pratensis, and Schizachyrium scoparium populations that had experienced five growing seasons of ambient CO₂ (aCO₂) or eCO₂ treatments and ambient or increased N deposition and planted these seeds into aCO₂ or eCO₂ environments. We found that the offspring eCO₂ treatments stimulated immediate increases in L. perennis and P. pratensis growth and that the maternal CO₂ environment influenced the magnitude of this growth response for L. perennis: biomass responses of offspring from the eCO₂ maternal treatments were only 54% that of the offspring from the aCO₂ maternal treatments. Similar trends were observed for P. pratensis and S. scoparium. We detected some evidence that long-term N treatments also altered growth responses to eCO₂; offspring reared from seed from maternal N-addition treatments tended to show greater positive growth responses to eCO₂ than offspring from ambient N maternal treatments. However, the effects of long-term N treatments on offspring survival showed the opposite pattern. Combined, our results suggest that transgenerational effects of eCO₂ and N-addition may influence the growth stimulation effects of eCO₂, potentially altering the long-term impacts of eCO₂ on plant populations.     

Recovery of cowpea seedling roots from exposure to toxic concentrations of trace metals

Rhizotoxic effects of many trace metals are known, but there is little information on recovery after exposure. Roots of 3-d-old cowpea (Vigna unguiculata (L.) Walp. cv. Caloona) seedlings were grown for 4 or 12 h in solutions of 960 μM Ca and 5 μM B at two concentrations (which reduce growth by 50 or 85%) of nine trace metals that rupture the outer layers of roots. Measured concentrations were 34 or 160 μM Al, 0.6 or 1.6 μM Cu, 2.2 or 8.5 μM ?Ga, 2.3 or 12 μM Gd, 0.8 or 1.9 μM Hg, 1.0 or 26 μM In, 2.4 or 7.3 μM La, 1.8 or 3.8 μM Ru, and 1.3 or 8.6 μM Sc. Roots were rinsed, transferred to solutions free of trace metals, and regrowth monitored for up to 48 h. Recovery from exposure to Hg occurred within 4 h, but regrowth was delayed for ≥?12 h with Al, Ga, or Ru. There was poor regrowth after 4 or 12 h exposure to Cu, Gd, In, La, or Sc. Roots recovered after being grown for 12 to 48 h in 170 μM Al, 5.1 μM? Ga, 2.0 μM Hg, or 1.4 μM Ru, but the extent of recovery was reduced with longer exposure time. Microscopy showed marked differences in symptoms on roots recovering from exposure to the various trace metals. Differences in (i) concentrations that are toxic, (ii) ability of roots to recover, (iii) time for recovery to occur, and (iv) symptoms that develop, suggest that each trace metal has a unique combination of rhizotoxic effects.     

The effects of nonvolatile toxic substances on the yeast growth during ethyl alcohol fermentations

Summary Nonvolatile toxins accumulated during alcohol fermentation reduce the yeast growth rate, but not the maximum cell concentration. Specific growth rates decline exponentially according to the increase in toxins. The accumulation of salts and proteins seem to be responsible for the inhibition.To whom all correspondence should be addressed.     

Transgenerational priming of immunity: maternal exposure to a bacterial antigen enhances offspring humoral immunity

Young vertebrates have limited capacity to synthesize antibodies and are dependent on the protection of maternally transmitted antibodies for humoral disease resistance early in life. However, mothers may enhance fitness by priming their offspring's immune systems to elevate disease resistance. Transgenerational induced defences have been documented in plants and invertebrates, but maternal priming of offspring immunity in vertebrates has been essentially neglected. To test the ability of mothers to stimulate the immune systems of offspring, we manipulated maternal and offspring antigen exposure in a wild population of birds, pied flycatchers (Ficedula hypoleuca). We show that immunization of the mother before egg laying apparently stimulates a transgenerational defence against pathogens by elevating endogenous offspring antibody production. If the disease environments encountered by mothers and offspring are similar, this transgenerational immune priming may allow young to better cope with the local pathogen fauna.     

Transgenerational effects of prenatal stress of different etiology

This paper considers the transgenerational effects of prenatal stress of different etiology. The impacts of stress factors on the biochemical and morphofunctional parameters of life of the mother, fetus, and offspring in the first and subsequent generations (F1?CF4) are estimated. Particular attention is paid to assessing changes in the parameters of physical development, the state of the hypothalamic-pituitary-adrenal axis, proinflammatory status, behavioral indicators, cognitive performance, and vegetative balance in the poststress period. Contemporary concepts of possible mechanisms of transgenerational transmission of the effects of prenatal stress are considered.     

Management of toxic substances and hazardous wastes

This paper describes the extent of the hazardous and toxic chemical waste problems in Canada and discusses the management, treatment, and disposal methods commonly used in North America and Europe. The treatment and disposal techniques covered are biological, physical-chemical, incineration technologies, and secure land disposal. Some of the available and emerging technologies for destruction of polychlorinated biphenyls are also described.