Different Levels Of Biological Organization Research Articles

Parental exposure to antidepressants has lasting effects on offspring? A case study with zebrafish

Fish have common neurotransmitter pathways with humans, exhibiting a significant degree of conservation and homology. Thus, exposure to fluoxetine makes fish potentially susceptible to biochemical and physiological changes, similarly to what is observed in humans. Over the years, several studies demonstrated the potential effects of fluoxetine on different fish species and at different levels of biological organization. However, the effects of parental exposure to unexposed offspring remain largely unknown. The consequences of 15-day parental exposure to relevant concentrations of fluoxetine (100 and 1000 ng/L) were assessed on offspring using zebrafish as a model organism. Parental exposure resulted in offspring early hatching, non-inflation of the swimming bladder, increased malformation frequency, decreased heart rate and blood flow, and reduced growth. Additionally, a significant behavioral impairment was also found (reduced startle response, basal locomotor activity, and altered non-associative learning during early stages and a negative geotaxis and scototaxis, reduced thigmotaxis, and anti-social behavior at later life stages). These behavior alterations are consistent with decreased anxiety, a significant increase in the expression of the monoaminergic genes slc6a4a (sert), slc6a3 (dat), slc18a2 (vmat2), mao, tph1a, and th2, and altered levels of monoaminergic neurotransmitters. Alterations in behavior, expression of monoaminergic genes, and neurotransmitter levels persisted until offspring adulthood. Given the high conservation of neuronal pathways between fish and humans, data show the possibility of potential transgenerational and multigenerational effects of pharmaceuticals’ exposure. These results reinforce the need for transgenerational and multigenerational studies in fish, under realistic scenarios, to provide realistic insights into the impact of these pharmaceuticals.

Thermo-priming triggers species-specific physiological and transcriptome responses in Mediterranean seagrasses

Heat priming improves plants tolerance to a recurring heat stress event. The underlying molecular mechanisms of heat priming are largely unknown in seagrasses. Here, ad hoc mesocosm experiments were conducted with two Mediterranean seagrass species, Posidonia oceanica and Cymodocea nodosa. Plants were first exposed to heat-priming, followed by a heat-triggering event. A comprehensive assessment of plant stress response across different levels of biological organization was performed at the end of the triggering event. Morphological and physiological results showed an improved response of heat-primed P. oceanica plants while in C. nodosa both heat- and non-primed plants enhanced their growth rates at the end of the triggering event. As resulting from whole transcriptome sequencing, molecular functions related to several cellular compartments and processes were involved in the response to warming of non-primed plants, while the response of heat-primed plants involved a limited group of processes. Our results suggest that seagrasses acquire a primed state during the priming event, that eventually gives plants the ability to induce a more energy-effective response when the thermal stress event recurs. Different species may differ in their ability to perform an improved heat stress response after priming. This study provides pioneer molecular insights into the emerging topic of seagrass stress priming and may benefit future studies in the field.

Assessing combined effects of long-term exposure to copper and marine heatwaves on the reef-forming serpulid Ficopomatus enigmaticus through a biomarker approach

Sessile benthic organisms can be affected by global changes and local pressures, such as metal pollution, that can lead to damages at different levels of biological organization. Effects of exposure to marine heatwaves (MHWs) alone and in combination with environmentally relevant concentration of copper (Cu) were evaluated in the reef-forming tubeworm Ficopomatus enigmaticus using a multi-biomarker approach. Biomarkers of cell membrane damage, enzymatic antioxidant defences, metabolic activity, neurotoxicity, and DNA integrity were analyzed. The exposure to Cu alone did not produce any significant effect. Exposure to MHWs alone produced effects only on metabolic activity (increase of glutathione S-transferase) and energy reserves (decrease in protein content). MHWs in combination with copper was the condition that most influenced the status of cell homeostasis of exposed F. enigmaticus. The combination of MHWs plus Cu exposure induced increase of protein carbonylation and glutathione S-transferase activity, decrease in protein/carbohydrate content and carboxylesterase activity. This study on a reef-forming organism highlighted the additive effect of a climate change-related stressor to metals pollution of marine and brackish waters.

Investigating students’ meaning-making of multiple visual representations of epigenetics at different levels of biological organisation

ABSTRACT The aim of this study is to investigate students’ meaning–making of multiple visual representations of epigenetics at different levels of biological organisation, and to discern what visual aspects of the multiple visual representations might influence students’ reasoning. Adopting an exploratory approach, we analysed how students made meaning of visually communicated epigenetics phenomena while pointing at and reasoning about the multiple visual representations as part of semi-structured focus groups. We investigated students’ meaning-making of the multiple visual representations by analysing their indications through physical pointing and accompanying verbal utterances. The analysis revealed meaning-making and the nature of linking between levels of organisation in four distinct patterns, namely intra horizontal linking, inter horizontal linking, one level vertical linking and two level vertical linking. In addition, five different visual characteristics of the multiple visual representations emerged as influencing students’ reasoning while linking between different organisation levels: multiple visual representations, salient visual features, analogous visual features, familiar visual elements, and textual adjuncts. The study shows that multiple visual representations at different levels of organisation can support students’ meaning-making of epigenetics, indicating that this way of communicating can be transferable to other biological domains. Potential implications for future research and teaching practice are provided.

Marine protected areas promote stability of reef fish communities under climate warming

Protection from direct human impacts can safeguard marine life, yet ocean warming crosses marine protected area boundaries. Here, we test whether protection offers resilience to marine heatwaves from local to network scales. We examine 71,269 timeseries of population abundances for 2269 reef fish species surveyed in 357 protected versus 747 open sites worldwide. We quantify the stability of reef fish abundance from populations to metacommunities, considering responses of species and functional diversity including thermal affinity of different trophic groups. Overall, protection mitigates adverse effects of marine heatwaves on fish abundance, community stability, asynchronous fluctuations and functional richness. We find that local stability is positively related to distance from centers of high human density only in protected areas. We provide evidence that networks of protected areas have persistent reef fish communities in warming oceans by maintaining large populations and promoting stability at different levels of biological organization.

Eco-evolutionary emergence of macroecological scaling in plankton communities.

Macroecological scaling patterns, such as between prey and predator biomass, are fundamental to our understanding of the rules of biological organization and ecosystem functioning. Although these scaling patterns are ubiquitous, how they arise is poorly understood. To explain these patterns, we used an eco-evolutionary predator-prey model parameterized using data for phytoplankton and zooplankton. We show that allometric scaling relationships at lower levels of biological organization, such as body-size scaling of nutrient uptake and predation, give rise to scaling relationships at the food web and ecosystem levels. Our predicted macroecological scaling exponents agree well with observed values across ecosystems. Our findings explicitly connect scaling relationships at different levels of biological organization to ecological and evolutionary mechanisms, yielding testable hypotheses for how observed macroecological patterns emerge.

The soil-microbe-plant resistome: A focus on the source-pathway-receptor continuum.

The One World, One Health concept implies that antibiotic resistance (AR) in the soil-microbe-plant resistome is intricately linked to the human resistome. However, the literature is mainly confined to sources and types of AR in soils or microbes, but comprehensive reviews tracking AR in the soil-microbe-plant resistome are limited. The present review applies the source-pathway-receptor concept to understand the sources, behaviour, and health hazards of the soil-microbe-plant resistome. The results showed that the soil-microbe-plant system harbours various antibiotic-resistance genes (ARGs), antibiotic-resistant bacteria (ARB), and mobile genetic elements (MGEs). Anthropogenic sources and drivers include soil application of solid waste, wastewater, biosolids, and industrial waste. Water-, wind-, and human-driven processes and horizontal gene transfer circulate AR in the soil-microbe-plant resistome. The AR in bulk soil, soil components that include soil microorganisms, soil meso- and macro-organisms, and possible mechanisms of AR transfer to soil components and ultimately to plants are discussed. The health risks of the soil-microbe-plant resistome are less studied, but potential impacts include (1) the transfer of AR to previously susceptible organisms and other resistomes, including the human resistome. Overall, the study tracks the behaviour and health risks of AR in the soil-plant system. Future research should focus on (1) ecological risks of AR at different levels of biological organization, (2) partitioning of AR among various phases of the soil-plant system, (3) physico-chemical parameters controlling the fate of AR, and (4) increasing research from low-income regions particularly Africa as most of the available literature is from developed countries.

Linking pollen limitation and seed dispersal effectiveness.

Seed production and dispersal are crucial ecological processes impacting plant demography, species distributions and community assembly. Plant-animal interactions commonly mediate both seed production and seed dispersal, but current research often examines pollination and seed dispersal separately, which hinders our understanding of how pollination services affect downstream dispersal services. To fill this gap, we propose a conceptual framework exploring how pollen limitation can impact the effectiveness of seed dispersal for endozoochorous and myrmecochorous plant species. We summarize the quantitative and qualitative effects of pollen limitation on plant reproduction and use Optimal Foraging Theory to predict its impact on the foraging behaviour of seed dispersers. In doing so, we offer a new framework that poses numerous hypotheses and empirical tests to investigate links between pollen limitation and seed dispersal effectiveness and, consequently, post-dispersal ecological processes occurring at different levels of biological organization. Finally, considering the importance of pollination and seed dispersal outcomes to plant eco-evolutionary dynamics, we discussed the implications of our framework for future studies exploring the demographic and evolutionary impacts of pollen limitation for animal-dispersed plants.

Product-inhibition feedbacks, not microbial population level tradeoffs or soil pH, regulate decomposition potential under nutrient eutrophication

Global eutrophication of growth-limiting nutrients for plants and microbes, including nitrogen (N) and phosphorus (P), can cause enzymatic feedbacks at different levels of biological organization that in turn drive soil organic matter (SOM) decomposition. Because land management practices, such as fire in mesic grasslands, also impact nutrient availability, it is important to understand how soil feedbacks may manifest under multifactorial change. Here, using a thirty-year field experiment that crosses N- and P-fertilization (alone and in combination) with contrasting fire treatments (annual burning and fire suppression) in a tallgrass prairie ecosystem, we evaluated evidence for three possible feedbacks (product-inhibition, enrichment of fast-growing copiotrophic taxa, and soil pH shift) by measuring soil extracellular enzyme activities (EEAs) and microbial community composition (16S rRNA genes) monthly for a year. Consistent with product-inhibition feedback predictions, both N-fertilization and fire suppression (which increases soil N availability) decreased N-acquiring relative to C-acquiring EEAs, suggesting reduced N limitation. P-fertilization did not lower acid phosphatase activity, thus the product-inhibition feedback hypothesis was not supported under P eutrophication conditions. Although N- and P-fertilization, alone and in combination, did decrease putatively oligotrophic populations in favor of putatively copiotrophic populations, the hypothesized tradeoff for faster growth, a concomitant decrease in all soil EEAs, was only observed in unburned soils fertilized with N. Finally, observed changes in EEAs were not driven by acidification, in contrast to other fertilization experiments. Overall, results suggest that higher N availability affects enzymatic feedbacks primarily through product-inhibition, but a threshold-like growth tradeoff (copiotrophic) response is possible under the combination of fire suppression and N-fertilization. Inherent soil properties may modulate site-specific responses to fertilization, as evidenced by weak pH and EEA responses to N- and P-fertilization, respectively. Finally, soil microbial community change following chronic fertilization did not reliably predict the “copiotrophic” feedback of reduced SOM decomposition potential.

Ocean acidification impairs seagrass performance under thermal stress in shallow and deep water

Despite the effects of ocean acidification (OA) on seagrasses have been widely investigated, predictions of seagrass performance under future climates need to consider multiple environmental factors. Here, we performed a mesocosm study to assess the effects of OA on shallow and deep Posidonia oceanica plants. The experiment was run in 2021 and repeated in 2022, a year characterized by a prolonged warm water event, to test how the effects of OA on plants are modulated by thermal stress. The response of P. oceanica to experimental conditions was investigated at different levels of biological organization. Under average seawater temperature, there were no effects of OA in both shallow and deep plants, indicating that P. oceanica is not limited by current inorganic carbon concentration, regardless of light availability. In contrast, under thermal stress, exposure of plants to OA increased lipid peroxidation and decreased photosynthetic performance, with deep plants displaying higher levels of heat stress, as indicated by the over-expression of stress-related genes and the activation of antioxidant systems. In addition, warming reduced plant growth, regardless of seawater CO2 and light levels, suggesting that thermal stress may play a fundamental role in the future development of seagrass meadows. Our results suggest that OA may exacerbate the negative effects of future warming on seagrasses.

Sex-specific responses of Ruditapes philippinarum to ocean acidification following gonadal maturation

Ocean acidification (OA) can seriously affect marine bivalves at different levels of biological organization, generating widespread consequences on progeny recruitment and population maintenance. Yet, few effort has been devoted to elucidating whether female and male bivalves respond differentially to OA in their reproductive seasons. Here, we estimated differences in physiological responses of female and male Manila clams (Ruditapes philippinarum) to OA during gonadal maturation. In comparison to OA-stressed male clams, females significantly depressed activities in enzymes related to energy metabolism (NKA, T-ATP), antioxidant defence (SOD and MDA), and non-specific immune function (ACP), and downregulated expression of AMPK that plays a key role in cellular metabolism, indicating that sex did significantly affect responses of R. philippinarum to OA. Such sex-based differences can be likely couched in energetic terms, given the much more energetically expensive cost of egg production than that of sperms. These results indicate that sex-specific responses to OA during reproductive seasons do exist in marine bivalves, and therefore accounting for such sex specificity is of paramount importance when projecting population sustainability and formulating conservation strategies in an acidifying ocean.

Marine heatwaves impact mortality of triploid Pacific oysters.

Studies of heatwave impacts on marine organisms are needed to understand biological tolerance to heat stress. Such studies should include integrative analyses across different levels of biological organization, which often reveal that predictions are non‐linear (e.g., gene–protein–physiology–organism). Further insights into potential evolutionary responses of organisms to rapid environmental change can be gained from formal genetic studies of multigenerational pedigreed families.

Impact of environmentally relevant concentrations of fluoxetine on zebrafish larvae: From gene to behavior

Fluoxetine is widely prescribed for the treatment of depressive states, acting at the level of the central nervous system, consequently affecting non-target organisms. This study aimed to investigate the influence of environmentally relevant fluoxetine concentrations (1–1000 ng/L) on Danio rerio development, assessing both embryotoxicity and behavior, antioxidant defense, gene expression and neurotransmitter levels at larval stage. Exposure to fluoxetine during early development was found to be able to accelerate embryo hatching in embryos exposed to 1, 10 and 100 ng/L, reduce larval size in 1000 ng/L, and increase heart rate in 10, 100 and 1000 ng/L exposed larvae. Behavioral impairments (decreased startle response and increased larvae locomotor activity) were associated with effects on monoaminergic systems, detected through the downregulation of key genes (vmat2, mao, tph1a and th2). In addition, altered levels of neurochemicals belonging to the serotonergic and dopaminergic systems (increased levels of tryptophan and norepinephrine) highlighted the sensitivity of early life stages of zebrafish to low concentrations of fluoxetine, inducing effects that may compromise larval survival. The obtained data support the necessity to test low concentrations of SSRIs in environmental risk assessment and the use of biomarkers at different levels of biological organization for a better understanding of modes of action.

Combined impact of elevated temperature and zinc oxide nanoparticles on physiological stress and recovery responses of Scylla serrata

Global climate change is the major cause behind unexpected fluctuations in temperature. In recent years, application of nanotechnology also has become widespread and nanomaterials are constantly being released into aquatic environments, posing a potential risk to various organisms and ecosystems. The lack of detailed understanding of how multiple stressors work, and how they differ from single stressors, impede to assess their combined effect on aquatic organisms and ecosystems. The prime aim of the current investigation is to decipher the toxicity of ZnO-NP after simultaneous exposure to a global environmental stressor, elevated temperature for 14 days, followed by a 7 days recovery period, on the eco-physiological responses of mud crab Scylla serrata collected from Sundarbans. Physiological energetics such as ingestion, assimilation, absorption, respiration, and excretion rates were measured to determine the Scope for growth (SfG). Additionally, we assessed various biomarkers from different levels of biological organisation (antioxidant, detoxification defence mechanisms, and lipid peroxidation levels) of the species. Combined stress attenuated the SfG in crabs which deteriorated further in the recovery phase. Oxidative stress also exacerbated under coalesced stress condition. Recovery was not observed in crabs with increased lipid peroxidation level under combined stress conditions. Elevated temperature disturbed the energy budget of crabs as mirrored by diminished energy left for compensatory actions under added metal stress, ultimately sensitizing the animals to ZnO NP pollutants. The current results advocate future ocean temperature to aggravate the impact of metal NP pollution and induce oxidative damage in S. serrata.

Multi-level biological responses of Daphnia magna exposed to settleable atmospheric particulate matter from metallurgical industries

Metallurgical industries are a continuous source of air pollution due to the amount of settleable particulate matter (SePM) they release. This SePM is a complex mixture formed by metallic nanoparticles and metals, which reach terrestrial and aquatic ecosystems and can be a significant source of contamination. The aim of this study was to evaluate the adverse effects of SePM at different levels of biological organization in order to estimate its ecological impacts on aquatic ecosystems. For this purpose, the crustacean Daphnia magna was exposed to different concentrations of SePM (0.01, 0.1, 1, 5, 10 g/L) using a multi-level response approach. The endpoints studied were: avoidance throughout 24 h in a non-forced exposure system, reproduction (total number of neonates per female after 21 days of exposure), acetylcholinesterase activity (AChE) after 48 h, and finally, the feeding rates during a short-term exposure (48 h) and a long-term exposure (21 day + 48 h). There was a negative effect of SePM on all responses measured at high concentrations. The avoidance was concentration-dependent and represented 88 % and 100 % at the two highest concentrations. The AChE activity was significantly inhibited at 5 and 10 g/L. The total number of neonates increased from 1 g/L of SePM and the first brood occurred earlier as of 5 g/L compared to control. The post-exposure feeding rates were lower during long-term exposure at the highest concentration. Chemical analyses were performed to characterize the metals present in this SePM, but this study did not report any direct relationship with toxicity, due to the chemical heterogeneity of the particles. The emission of compounds caused by anthropogenic activity may have significant ecological consequences, so it is important to consider these possible effects on aquatic biota generated by the mixture of metals present in SePM originated from metallurgical activities. Environmental and sectorial regulations are needed to prevent contamination and ecological disturbances.

Eco-evolutionary maintenance of diversity in fluctuating environments.

Growing evidence suggests that temporally fluctuating environments are important in maintaining variation both within and between species. To date, however, studies of genetic variation within a population have been largely conducted by evolutionary biologists (particularly population geneticists), while population and community ecologists have concentrated more on diversity at the species level. Despite considerable conceptual overlap, the commonalities and differences of these two alternative paradigms have yet to come under close scrutiny. Here, we review theoretical and empirical studies in population genetics and community ecology focusing on the 'temporal storage effect' and synthesise theories of diversity maintenance across different levels of biological organisation. Drawing on Chesson's coexistence theory, we explain how temporally fluctuating environments promote the maintenance of genetic variation and species diversity. We propose a further synthesis of the two disciplines by comparing models employing traditional frequency-dependent dynamics and those adopting density-dependent dynamics. We then address how temporal fluctuations promote genetic and species diversity simultaneously via rapid evolution and eco-evolutionary dynamics. Comparing and synthesising ecological and evolutionary approaches will accelerate our understanding of diversity maintenance in nature.

Cell type and gene regulatory network approaches in the evolution of spiralian biomineralisation.

Biomineralisation is the process by which living organisms produce hard structures such as shells and bone. There are multiple independent origins of biomineralised skeletons across the tree of life. This review gives a glimpse into the diversity of spiralian biominerals and what they can teach us about the evolution of novelty. It discusses different levels of biological organisation that may be informative to understand the evolution of biomineralisation and considers the relationship between skeletal and non-skeletal biominerals. More specifically, this review explores if cell type and gene regulatory network approaches could enhance our understanding of the evolutionary origins of biomineralisation.

Northern shrimp from multiple origins show similar sensitivity to global change drivers, but different cellular energetic capacity.

Species with a wide distribution can experience significant regional variation in environmental conditions, to which they can acclimatize or adapt. Consequently, the geographic origin of an organism can influence its responses to environmental changes, and therefore its sensitivity to combined global change drivers. This study aimed at determining the physiological responses of the northern shrimp, Pandalus borealis, at different levels of biological organization and from four different geographic origins, exposed to elevated temperature and low pH to define its sensitivity to future ocean warming and acidification. Shrimp sampled within the northwest Atlantic were exposed for 30days to combinations of three temperature (2, 6 or 10°C) and two pH levels (7.75 or 7.40). Survival, metabolic rates, whole-organism aerobic performance and cellular energetic capacity were assessed at the end of the exposure. Our results show that shrimp survival was negatively affected by temperature above 6°C and low pH, regardless of their origin. Additionally, shrimp from different origins show overall similar whole-organism performances: aerobic scope increasing with increasing temperature and decreasing with decreasing pH. Finally, the stability of aerobic metabolism appears to be related to cellular adjustments specific to shrimp origin. Our results show that the level of intraspecific variation differs among levels of biological organization: different cellular capacities lead to similar individual performances. Thus, the sensitivity of the northern shrimp to ocean warming and acidification is overall comparable among origins. Nonetheless, shrimp vulnerability to predicted global change scenarios for 2100 could differ among origins owing to different regional environmental conditions.

The effects of climate change on the ecology of fishes

Ocean warming and acidification are set to reshuffle life on Earth and alter ecological processes that underpin the biodiversity, health, productivity, and resilience of ecosystems. Fishes contribute significantly to marine, estuarine, and freshwater species diversity and the functioning of marine ecosystems, and are not immune to climate change impacts. Whilst considerable effort has been placed on studying the effects of climate change on fishes, much emphasis has been placed on their (eco)physiology and at the organismal level. Fishes are affected by climate change through impacts at various levels of biological organisation and through a large variety of traits, making it difficult to make generalisations regarding fish responses to climate change. Here, we briefly review the current state of knowledge of climate change effects on fishes across a wide range of subfields of fish ecology and evaluate these effects at various scales of biological organisation (from genes to ecosystems). We argue that a more holistic synthesis of the various interconnected subfields of fish ecology and integration of responses at different levels of biological organisation are needed for a better understanding of how fishes and their populations and communities might respond or adapt to the multi-stressor effects of climate change. We postulate that studies using natural analogues of climate change, meta-analyses, advanced integrative modelling approaches, and lessons learned from past extreme climate events could help reveal some general patterns of climate change impacts on fishes that are valuable for management and conservation approaches. Whilst these might not reveal many of the underlying mechanisms responsible for observed biodiversity and community change, their insights are useful to help create better climate adaptation strategies for their preservation in a rapidly changing ocean.

Ecotoxicity of single and mixture of perfluoroalkyl substances (PFOS and PFOA) in soils to the earthworm Aporrectodea caliginosa

Per and polyfluoroalkyl substances (PFAS) are persistent compounds that are massively used in industry, consumer goods and fire-fighting foams. Soil contamination by PFAS is a major environmental concern, and there is a lack of knowledge on both their ecotoxicological mechanisms and the concentrations that induce adverse effects especially to non-target organisms, particularly in the case of PFAS mixtures. This study contributes to filling these gaps by assessing and modelling the effects of PFAS (in single and in mixtures for PFOS and PFOA at different environmental doses) on juvenile endogeic earthworms of a common species in European soils (Aporrectodea caliginosa) at different levels of biological organization (sub-individual and individual). The results showed for the first time combined strong ecotoxicological effects of PFAS on earthworm survival, integumental integrity, growth, sexual maturity and on genomic stability notably with the induction of DNA breaks associated with no abnormal oxidative DNA-lesion levels. Our results demonstrated significant effects at 0.3 mg kg−1 and additive effects in case of mixtures.