WingAnalogy: a computer vision-based tool for automated insect wing asymmetry and morphometry analysis

WingAnalogy is a computer tool for automated insect wing morphology and asymmetry analysis. It facilitates project management, enabling users to import pairs of wing images obtained from individual insects, such as left and right, fore- and hindwings. WingAnalogy employs image processing and computer vision to segment wing structures and extract cell boundaries, and junctions. It quantifies essential metrics encompassing cell and wing characteristics, including area, length, width, circularity, and centroid positions. It enables users to scale and superimpose wing images utilizing Particle Swarm Optimization (PSO). WingAnalogy computes regression, Normalized Root Mean Square Error (NRMSE), various cell-based parameters, and distances between cell centroids and junctions. The software generates informative visualizations, aiding researchers in comprehending and interpreting asymmetry patterns. WingAnalogy allows for dividing wings into up to five distinct wing cell sets, facilitating localized comparisons. The software excels in report generation, providing detailed asymmetry measurements in PDF, CSV, and TXT formats.

Biological impact of Chornobyl radiation: a review of recent progress

The incident of Chernobyl Nuclear Power Plant (CNPP) explosion has pioneered a plethora of studies unfolding various biological effects of radiation stress on several living systems. Determining radiation dose rates at which both acute and chronic biological effects occur in different biological systems will aid in the ex-situ generation of radiation-tolerant organisms. So far, the accumulation of data on different radiation doses from Chernobyl area demonstrating various biological impacts has not been documented altogether vastly. Therefore, this review aims to document the recorded doses in CNPP over the years at which different biological changes have been observed in plants, soil, aquatic organisms, birds, and animals. A total of 72 peer-reviewed papers obtained from PubMed, Google Scholar, Scopus, and Research4life were included in this review. A few factors have come under attention in this review. Firstly, plant and soil systems combinedly showed the most published studies after the catastrophe where plants showed a higher frequency of DNA methylation in their genome to resist radiation stress. Secondly, reduced species abundance, chromosomal aberrations, increased sterility, and mortality were mostly observed in the aftermath of Chernobyl catastrophe among plants, soil, aquatic organisms, birds, and small mammals. Furthermore, major scares of data after 2018 were prominently observed. Very few studies on radiation dose levels after 2018 are available. Hence, a major research area has emerged for radiation biologists to study present radiation levels and any genetic changes in the recent generation of the original victim species. This will help provide a standard dataset that can act as a reference resource for radiation biologists and future research on the impact of both acute and chronic radiation on the different biological systems.

Evolutionary approach for pollution study: The case of ionizing radiation

Estimating the consequences of environmental changes, specifically in a global change context, is essential for conservation issues. In the case of pollutants, the interest in using an evolutionary approach to investigate their consequences has been emphasized since the 2000s, but these studies remain rare compared to the characterization of direct effects on individual features. We focused on the study case of anthropogenic ionizing radiation because, despite its potential strong impact on evolution, the scarcity of evolutionary approaches to study the biological consequences of this stressor is particularly true. In this study, by investigating some particular features of the biological effects of this stressor, and by reviewing existing studies on evolution under ionizing radiation, we suggest that evolutionary approach may help provide an integrative view on the biological consequences of ionizing radiation. We focused on three topics: (i) the mutagenic properties of ionizing radiation and its disruption of evolutionary processes, (ii) exposures at different time scales, leading to an interaction between past and contemporary evolution, and (iii) the special features of contaminated areas called exclusion zones and how evolution could match field and laboratory observed effects. This approach can contribute to answering several key issues in radioecology: to explain species differences in the sensitivity to ionizing radiation, to improve our estimation of the impacts of ionizing radiation on populations, and to help identify the environmental features impacting organisms (e.g., interaction with other pollution, migration of populations, anthropogenic environmental changes). Evolutionary approach would benefit from being integrated to the ecological risk assessment process.

Exposure to ionizing radiation and liver histopathology in the tree frogs of Chornobyl (Ukraine)

Ionizing radiation has the potential to damage organic molecules and decrease the health and survival of wildlife. The accident at the Chornobyl Nuclear Plant (Ukraine, 1986) led to the largest release of radioactive material to the environment. Among the different organs of a vertebrate, the liver plays a crucial role in detoxification processes, and has been used as a biomarker to investigate cellular damage in ecotoxicological research. Here, we examined the impact of the exposure to the current levels of ionizing radiation present in the Chornobyl Exclusion Zone on the liver of Eastern tree frogs (Hyla orientalis). We quantified the area of melanomacrophage cells and morphological variables of hepatocytes, two cell types often used to estimate damage caused by pollutants in vertebrates. First, we investigated whether these hepatic parameters were indicative of frog (individual) condition. Then, we analyzed the effect of individual absorbed dose rates and ambient radiation levels on frog livers. Most of the studied parameters were correlated with individual body condition (a good predictor of amphibian fitness and survival). We did not detect marked morphological lesions in the liver of frogs captured in medium-high radiation environments. The area occupied by melanomacrophages and the morphology of hepatocytes did not change across a gradient of radiocontamination covering two orders of magnitude. Once accounting for body condition and sampling locality, the area of melanomacrophages was lower in areas with high radiation levels. Finally, the area occupied by melanomacrophages was not linked to dorsal skin coloration. Our results indicate that current levels of radiation experienced by tree frogs in Chornobyl do not cause histopathological damage in their liver. These results agree with previous physiological work in the species in the Chornobyl area, and encourage further molecular and physiological research to fully disentangle the current impact of the Chornobyl accident on wildlife.

Ionizing radiation affects the demography and the evolution of Caenorhabditis elegans populations

Ionizing radiation can reduce survival, reproduction and affect development, and lead to the extinction of populations if their evolutionary response is insufficient. However, demographic and evolutionary studies on the effects of ionizing radiation are still scarce. Using an experimental evolution approach, we analyzed population growth rate and associated change in life history traits across generations in Caenorhabditis elegans populations exposed to 0, 1.4, and 50.0 mGy.h^-1 of ionizing radiation (gamma external irradiation). We found a higher population growth rate in the 1.4 mGy.h^-1 treatment and a lower in the 50.0 mGy.h^-1 treatment compared to the control. Realized fecundity was lower in both 1.4 and 50.0 mGy.h^-1 than control treatment. High irradiation levels decreased brood size from self-fertilized hermaphrodites, specifically early brood size. Finally, high irradiation levels decreased hatching success compared to the control condition. In reciprocal-transplant experiments, we found that life in low irradiation conditions led to the evolution of higher hatching success and late brood size. These changes could provide better tolerance against ionizing radiation, investing more in self-maintenance than in reproduction. These evolutionary changes were with some costs of adaptation. This study shows that ionizing radiation has both demographic and evolutionary consequences on populations.

Contribution of transposable elements to transgenerational effects of chronic radioactive exposure of natural populations of Drosophila melanogaster living for a long time in the zone of the Chernobyl nuclear disaster

The accident at the Chernobyl Nuclear Power Plant (ChNPP) led to the negative impact of chronic radioactive contamination on populations of organisms associated with the transgenerational transmission of genome instability. When the destabilization of genome, different genetic damages occur, the accumulation of which leads to the formation of mutations, morphological anomalies, and mortality in the offspring. The mechanisms underlying the manifestation of transgenerational events in the offspring of irradiated parents are not well understood. In this study, for the first time, the features of the influence of transposable elements (TEs) on the long-term biological consequences of the ChNPP are considered. In this work, specimens of D. melanogaster obtained from natural populations in 2007 in the areas of the ChNPP with heterogeneous radioactive contamination were studied. The descendants from these populations were maintained in laboratory (inbred) conditions for 160 generations. A stable transgenerational transmission of dominant lethal mutations (DLMs) to the offspring of all studied populations was shown. The DLM frequencies strongly were correlated with the level of survival of offspring. The mean frequencies of recessive sex-linked lethal mutations varied at the level of spontaneous point mutations. The simultaneous presence of P, hobo and I elements indicates that the studied populations do not have a definite cytotype, their phenotypic status is unstable. The behavior of TEs in the genomes of offspring depends not only on parental exposure, but also on origin of population, distance to the ChNPP, and inbred conditions. The obtained results confirm the hypothesis that TEs are involved in transgenerational transmission and accumulation of mutations by the offspring of irradiated parents. The TEs pattern present in the Chernobyl genomes of D. melanogaster is a peculiar of epigenetic mechanism for the regulation of plasticity and adaptation of populations living for many generations under conditions of a technogenically caused radiation background.

Lack of impact of radiation on blood physiology biomarkers of Chernobyl tree frogs

BACKGROUND

Human actions have altered natural ecosystems worldwide. Among the many pollutants released to the environment, ionizing radiation can cause severe damage at different molecular and functional levels. The accident in the Chernobyl Nuclear Power Plant (1986) caused the largest release of ionizing radiation to the environment in human history. Here, we examined the impact of the current exposure to ionizing radiation on blood physiology biomarkers of adult males of the Eastern tree frog (Hyla orientalis) inhabiting within and outside the Chernobyl Exclusion Zone. We measured the levels of eight blood parameters (sodium, potassium, chloride, ionized calcium, total carbon dioxide, glucose, urea nitrogen, and anion gap), physiological markers of homeostasis, as well as of liver and kidney function.

RESULTS

Levels of blood physiology biomarkers did not vary in function of the current exposure of tree frogs to ionizing radiation within the Chernobyl Exclusion Zone. Physiological blood levels were similar in frogs inhabiting Chernobyl (both in areas with medium-high or low radiation) than in tree frogs living outside Chernobyl exposed only to background radiation levels.

CONCLUSIONS

The observed lack of effects of current radiation levels on blood biomarkers can be a consequence of the low levels of radiation currently experienced by Chernobyl tree frogs, but also to the fact that our sampling was restricted to active breeding males, i.e. potentially healthy adult individuals. Despite the clear absence of effects of current radiation levels on physiological blood parameters in tree frogs, more research covering different life stages and ecological scenarios is still needed to clarify the impact of ionizing radiation on the physiology, ecology, and dynamics of wildlife inhabiting radioactive-contaminated areas.

Transgenerational effects in offspring of chronically irradiated populations of Drosophila melanogaster after the Chernobyl accident

The zone of the Chernobyl nuclear disaster represents the largest area of chronic low-intensity radioactive impact on the natural ecosystems. The effects of chronic low-dose irradiation for natural populations of organisms and their offspring are unknown. The natural populations of Drosophila melanogaster sampled in 2007 in Chernobyl sites with different levels of radiation contamination were investigated. The offspring of specimens from these populations were studied under laboratory conditions to assess the effects of parental irradiation on the mutation process and survival of the offspring. Transgenerational effects of radioactive contamination were observed at the level of gross chromosomal rearrangements (dominant lethal mutations). The frequency of point/gene mutations (recessive sex-linked lethal mutations) of the offspring of the irradiated parents corresponded to the actual level of spontaneous mutations. The survival rate of offspring decreased over 160 generations and significantly correlated with the dominant lethal mutation levels. Our results provide a compelling evidence that other factors (distance from the Chernobyl Nuclear Power Plant, time after the initial exposure, selection site and origin of population) can affect the changes in the levels of the studied parameters along with the parental radiation exposure. They can also make a significant contribution to the health of the offspring of animals exposed to radioactive contamination. These data should be useful for future radioecological studies which will clarify the true mechanisms of transgenerational inheritance and generation of mutations to the offspring of chronically irradiated animals and their reactions to the interaction of various environmental factors.

A review of the impact on the ecosystem after ionizing irradiation: wildlife population

PURPOSE

On 26 April 1986, reactor 4 at the Chernobyl power plant underwent a catastrophic failure leading to core explosions and open-air fires. On 11 March 2011, a combination of earthquake and tsunami led to a similar disaster at the Fukushima Daiichi power plant. In both cases, radioactive isotopes were released and contaminated the air, soil and water in a substantial area around the power plants. Humans were evacuated from the immediate regions but the wildlife stayed and continued to be affected by the ongoing high radiation exposure initially and later decayed amounts of fallout dusts with time. In this review, we will examine the significant effects of the increased radiation on vegetation, insects, fish, birds and mammals.

CONCLUSIONS

The initial intense radiation in these areas has gradually begun to decrease but still remains high. Adaptation to radiation is evident and the ecosystems have dynamically changed from the periods immediately after the accidents to the present day. Understanding the molecular mechanisms that allow the adaptation and recovery of wildlife to chronic radiation challenges would aid in future attempts at ecosystem remediation in the wake of such incidents.

Genetic mechanisms of formation of radiation-induced instability of the genome and its transgenerational effects in the descendants of chronically irradiated individuals of Drosophila melanogaster

The article is devoted to the study of the role of intracellular mechanisms in the formation of radiation-induced genetic instability and its transgenerational effect in cells of different tissues of the descendants of Drosophila melanogaster mutant strains whose parents were exposed to chronic radiation (0.42 and 3.5 mGy/h). The level of DNA damage (alkali-labile sites (ALS), single-strand (SSB) and double-strand (DSB) breaks) in cells of somatic (nerve ganglia, imaginal discs) and generative (testis) tissues from directly irradiated animals and their unirradiated offspring was evaluated. Confident transgenerational instability (on the level of ALSs and SSBs), observed only in somatic tissues and only at the higher dose rate, is characteristic for mus209 mutant strains defective in excision repair and, less often, for mus205 and mus210 mutant strains. The greatest manifestation of radiation-induced genetic instability was found in evaluating the DSBs. Dysfunction of the genes mus205, mus304, mei-9 and mei-41, which are responsible for postreplicative repair, excision repair, recombination and control of the cell cycle, affects transgenerational changes in the somatic tissues of the offspring of parents irradiated in both low and high dose rates. In germ cells, the key role in maintaining genetic stability under chronic irradiation is played by the non-recombination postreplication repair mus101 gene. We revealed the tissue specificity of the radiation-induced effects, transgenerational transmission and accumulation of DNA damage to descendants of chronically irradiated animals.

The relative strengths of rapid and delayed density dependence acting on a terrestrial herbivore change along a pollution gradient

Animal populations vary in response to a combination of density-dependent and density-independent forces, which interact to drive their population dynamics. Understanding how abiotic forces mediate the form and strength of density-dependent processes remains a central goal of ecology, and is of increasing urgency in a rapidly changing world. Here, we report for the first time that industrial pollution determines the relative strength of rapid and delayed density dependence operating on an animal population. We explored the impacts of pollution and climate on the population dynamics of an eruptive leafmining moth, Phyllonorycter strigulatella, around a coal-fired power plant near Apatity, north-western Russia. Populations were monitored at 14 sites over 26 years. The relative strengths of rapid and delayed density dependence varied with distance from the power plant. Specifically, the strength of rapid density dependence increased while the strength of delayed density dependence decreased with increasing distance from the pollution source. Paralleling the increasing strength of rapid density dependence, we observed declines in the densities of P. strigulatella, increases in predation pressure from birds and ants, and declines in an unknown source of mortality (perhaps plant antibiosis) with increasing distance from the power plant. In contrast to the associations with pollution, associations between climate change and leafminer population densities were negligible. Our results may help to explain the outbreaks of insect herbivores that are frequently observed in polluted environments. We show that they can result from the weakening of rapid (stabilizing) density dependence relative to the effects of destabilizing delayed density dependence. Moreover, our results may explain some of the variation reported in published studies of animal populations in polluted habitats. Variable results may emerge in part because of the location of the study sites on different parts of pollution gradients. Finally, in a rapidly changing world, effects of anthropogenic pollution may be as, or more, important than are effects of climate change on the future dynamics of animal populations.