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1.
Anthropogenic factors can have simultaneous positive and negative effects on parasite transmission, and thus it is important to quantify their net effects on disease risk. Net effects will be a product of changes in the survival and traits (e.g., susceptibility, infectivity) of both hosts and parasites. In separate laboratory experiments, we exposed cercariae of the trematode Echinostoma trivolvis, and its first and second intermediate hosts, snails (Planorbella trivolvis) and green frog tadpoles (Rana clamitans), respectively, to one of four common pesticides (atrazine, glyphosate, carbaryl, and malathion) at standardized, ecologically relevant concentrations (201.0, 3700.0, 33.5, and 9.6 microg/L, respectively). We measured effects of pesticide exposure on six mechanisms important to this host-parasite interaction: (1) survival of E. trivolvis cercariae over 26 hours, (2) tadpole survival over two weeks, (3) snail survival over four weeks, (4) snail growth and fecundity, (5) cercarial infectivity, and (6) tadpole susceptibility to a fixed number of cercariae. Pesticides, in general, caused significantly greater mortality of E. trivolvis cercariae than did control treatments, but atrazine was the lone chemical to significantly reduce cercarial survival (LC50 value = 267 mg/L) and then only at concentrations greater than commonly found in aquatic ecosystems (> or =200 microg/L). None of the pesticides significantly enhanced E. trivolvis virulence, decreased tadpole survival, or reduced snail survival, growth, or fecundity. Sublethal exposure of the cercariae to the pesticides (4 h) did not significantly affect trematode encystment in R. clamitans. In contrast, sublethal exposure of R. clamitans to each of the four pesticides increased their susceptibility as measured by the percentage of cercariae that encysted. The reduction in exposure to trematodes due to pesticide-induced cercarial mortality (a density-mediated effect) was smaller than the pesticide-induced increase in amphibian susceptibility (a trait-mediated effect), suggesting that the net effect of exposure to environmentally realistic levels of pesticides will be to elevate amphibian trematode infections. These findings highlight the importance of elucidating the lethal and sublethal effects of anthropogenic factors on both hosts and parasites to understand the mechanisms underlying changes in parasite transmission and virulence, an approach that is especially needed for amphibians, a taxon experiencing global disease-related declines.  相似文献   

2.
Anthropogenic-derived stressors in the environment, such as contaminants, are increasingly considered important cofactors that may decrease the immune response of amphibians to pathogens. Few studies, however, have integrated amphibian disease and contaminants to test this multiple-stressor hypothesis for amphibian declines. We examined whether exposure to sublethal concentrations of a glyphosate-based herbicide and two strains of the pathogenic chytrid fungus, Batrachochrytrium dendrobatidis (Bd) could: (1) sublethally affect wood frogs (Lithobates sylvaticus) by altering the time to and size at metamorphosis, and (2) directly affect survivability of wood frogs after metamorphosis. Neither Bd strain nor herbicide exposure alone significantly altered growth or time to metamorphosis. The two Bd strains did not differ in their pathogenicity, and both caused mortality in post-metamorphic wood frogs. There was no evidence of an interaction between treatments, indicating a lack of herbicide-induced susceptibility to Bd. However, the trends in our data suggest that exposure of wood frogs to a high concentration of glyphosate-based herbicide may reduce Bd-caused mortality compared to animals exposed to Bd alone. These results exemplify the complexities inherent when populations are coping with multiple stressors. In this case, the perceived stressor, glyphosate-based herbicide, appeared to affect the pathogen more than the host's immune system, relieving the host from disease-caused effects. This suggests caution when invoking multiple stressors as a cause for increased disease susceptibility and indicates that the effects of multiple stressors on disease outcome depend on the interrelationships of stressors to both the pathogen and the host.  相似文献   

3.
A leading hypothesis of amphibian population declines is that combinations of multiple stressors contribute to declines. We examined the role that chemical contamination, competition, and predation play singly and in combination in aquatic amphibian communities. We exposed larvae of American toads (Bufo americanus), southern leopard frogs (Rana sphenocephala), and spotted salamanders (Ambystoma maculatum) to overwintered bullfrog tadpoles (R. catesbeiana), bluegill sunfish (Lepomis macrochirus), the insecticide carbaryl, and ammonium nitrate fertilizer in 1000-L mesocosms. Most significantly, our study demonstrated that the presence of multiple factors reduced survival of B. americanus and A. maculatum and lengthened larval periods of R. sphenocephala. The presence of bluegill had the largest impact on the community; it eliminated B. americanus and A. maculatum and reduced the abundance of R. sphenocephala. Chemical contaminants had the second strongest effect on the community with the insecticide, reducing A. maculatum abundance by 50% and increasing the mass of anurans (frogs and toads) at metamorphosis; the fertilizer positively influenced time and mass at metamorphosis for both anurans and A. maculatum. Presence of overwintered bullfrogs reduced mass and increased time to metamorphosis of anurans. While both bluegill and overwintered bullfrog tadpoles had negative effects on the amphibian community, they performed better in the presence of one another and in contaminated habitats. Our results indicate that predicting deleterious combinations from single-factor effects may not be straightforward. Our research supports the hypothesis that combinations of factors can negatively impact some amphibian species and could contribute to population declines.  相似文献   

4.
Outbreaks of disease in herbivorous sea urchins have led to ecosystem phase shifts from urchin barrens to kelp beds (forests) on temperate rocky reefs, and from coral to macroalgal-dominated reefs in the tropics. We analyzed temporal patterns in epizootics that cause mass mortality of sea urchins, and consequent phase shifts, based on published records over a 42-year period (1970–2012). We found no evidence for a general increase in disease outbreaks among seven species of ecologically important and intensively studied sea urchins. Periodic waves of recurrent amoebic disease of Strongylocentrotus droebachiensis in Nova Scotia coincide with periods when the system was in a barrens state and appear to have increased in frequency. In contrast, following a major epizootic that decimated Diadema antillarum throughout the Caribbean in 1983, subsequent outbreaks of disease were highly localized and none have been reported since 1991. Epizootics of Strongylocentrotus in the NW Atlantic and NE Pacific, and Paracentrotus and Diadema in the eastern Atlantic, have been linked to climate change and overfishing of sea urchin predators. The spatial extent of recurrent disease outbreaks in these species, and the frequency of phase shifts associated with these epizootics, has decreased over time due to the expansion of the macroalgal state and its stabilization through positive feedback mechanisms. Longitudinal studies to monitor disease outbreaks in sea urchin populations and improved techniques to identify causative agents are needed to assess changes in the frequency and extent of epizootics, which can profoundly affect the structure and functioning of coastal marine ecosystems.  相似文献   

5.
There is increasing concern for the disruptive effects seen in aquatic species exposed to environmental contaminants. However, few studies have investigated the impact of such contaminants on the behavior of individuals living in exposed waters. Contaminant exposure can affect animal populations by disrupting behaviors including feeding, locomotion, and mating. In this study, we examined how living in an ecosystem polluted by combinations of polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and heavy metals (arsenic, cadmium, iron, lead, zinc) impacts contest behavior in the round goby (Neogobius melanostomus). Fish collected from heavily contaminated and cleaner sites in Lake Ontario were subjected to a resource contest to determine the effect of these contaminants on aggression and the establishment of dominance hierarchies, which in turn influence access to food, shelter, and mating opportunities. Dominance establishment (a clear resource winner) was less obvious among fish from the contaminated site compared to the more stable hierarchies that formed between pairs of fish from the clean site. Pairs of fish from the contaminated site performed more assessment displays compared to fish from clean sites. These results suggest that the costs of living in an environment under exposure can shape behavioral repertoires. The altered conflict resolution strategies of contaminated fish may reflect impaired cognitive function, sensory perception, and/or higher metabolic load associated with aggression. This study provides support for the utilization of quantifiable behavioral differences as ecologically relevant measures of contaminant exposure.  相似文献   

6.
Among the environmental contaminants recognised for their toxicity and their global presence, heavy metals are certainly a major concern. They can elicit a number of immunomodulatory effects leading ultimately to an enhanced susceptibility (sensitivity) of immune cells to microbial agents and the appearance of neoplastic diseases and autoimmune phenomena. Heavy metals also provoke changes in the function(s) of immune cells. A striking biological effect of heavy metals is the induction of intracellular thiols (cysteine, glutathione, metallothioneins). Thiols are involved in many physiological processes, including protection from free radical damage and detoxification of chemicals. The purpose of this study was to assess the differences of susceptibility (sensitivity) in both pre-activated (concanavalin A was used) and non-pre-activated cells in the presence of heavy metals. Five were evaluated on murine splenocytes. The lymphoblastic proliferation test was performed for lymphocytes and a phagocytosis test for macrophages. Data showed that the levels of thiols in the pre-activated cells are greater than non-pre-activated cells following exposure to various heavy metals; macrophages were more resistant than lymphocytes to the toxic effects of heavy metals, and pre-activated cells were more resistant than cells at rest. One possible explanation is that macrophages produce more thiols than lymphocytes and this provides an increased protection from the deleterious effects of heavy metals.  相似文献   

7.
阿特拉津可对雄性脊椎动物生殖系统造成不良影响,但其中分子机制尚不明了。本文作者将非洲爪蟾(Xenopus laevis)暴露于100 ppb的阿特拉津120 d,利用同位素标记相对和绝对定量(iTRAQ)技术检测了非洲爪蟾睾丸和卵巢中蛋白图谱的变化,结果显示100 ppb阿特拉津可影响爪蟾发育,延迟和阻碍雄性细精管的形成。组学分析显示,睾丸中143种以及卵巢中121种蛋白均表达异常,这些蛋白与细胞凋亡、细胞间紧密连接以及代谢途径相关。
精选自Xiuping Chen, Jiamei Wang, Haojun Zhu, Jiatong Ding and Yufa Peng. Proteomics analysis of Xenopus laevis gonad tissue following chronic exposure to atrazine. Environmental Toxicology and Chemistry: Volume 34, Issue 8, pages 1744–1750, August 2015. DOI: 10.1002/etc.2980
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.2980/full  相似文献   

8.
阿特拉津可对雄性脊椎动物生殖系统造成不良影响,但其中分子机制尚不明了。本文作者将非洲爪蟾(Xenopus laevis)暴露于100 ppb的阿特拉津120 d,利用同位素标记相对和绝对定量(iTRAQ)技术检测了非洲爪蟾睾丸和卵巢中蛋白图谱的变化,结果显示100 ppb阿特拉津可影响爪蟾发育,延迟和阻碍雄性细精管的形成。组学分析显示,睾丸中143种以及卵巢中121种蛋白均表达异常,这些蛋白与细胞凋亡、细胞间紧密连接以及代谢途径相关。
精选自Xiuping Chen, Jiamei Wang, Haojun Zhu, Jiatong Ding and Yufa Peng. Proteomics analysis of Xenopus laevis gonad tissue following chronic exposure to atrazine. Environmental Toxicology and Chemistry: Volume 34, Issue 8, pages 1744–1750, August 2015. DOI: 10.1002/etc.2980
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.2980/full  相似文献   

9.
阿特拉津可对雄性脊椎动物生殖系统造成不良影响,但其中分子机制尚不明了。本文作者将非洲爪蟾(Xenopus laevis)暴露于100 ppb的阿特拉津120 d,利用同位素标记相对和绝对定量(iTRAQ)技术检测了非洲爪蟾睾丸和卵巢中蛋白图谱的变化,结果显示100 ppb阿特拉津可影响爪蟾发育,延迟和阻碍雄性细精管的形成。组学分析显示,睾丸中143种以及卵巢中121种蛋白均表达异常,这些蛋白与细胞凋亡、细胞间紧密连接以及代谢途径相关。
精选自Xiuping Chen, Jiamei Wang, Haojun Zhu, Jiatong Ding and Yufa Peng. Proteomics analysis of Xenopus laevis gonad tissue following chronic exposure to atrazine. Environmental Toxicology and Chemistry: Volume 34, Issue 8, pages 1744–1750, August 2015. DOI: 10.1002/etc.2980
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.2980/full  相似文献   

10.
陈建军  张坤  祖艳群  李元 《生态环境》2011,20(11):1753-1757
通过盆栽试验探讨了种植皇竹草(Pennisetum hydridum)对阿特拉津污染土壤的修复效果,阿特拉津对皇竹草生长的影响,以及皇竹草对土壤微生物数量的影响,以期为阿特拉津污染土壤的植物修复提供参考。结果表明:在≤200 mg.kg-1质量分数范围以内,种植皇竹草对土壤阿特拉津的初期降解效率比对照明显提高,最大提高了29.64%,达到显著或极显著差异;阿特拉津质量分数在≤200 mg.kg-1范围内对皇竹草株高没有影响,≤50 mg.kg-1质量分数范围内对生物量没有影响,根冠比变化不明显;随阿特拉津质量分数的增加皇竹草根际和非根际土壤中的细菌、真菌、放线菌数量均呈先增加后减少的趋势,在质量分数为100 mg.kg-1时达到最大,根际土壤中细菌和放线菌数量明显高于非根际土壤,真菌数量在根际与非根际土壤中变化不明显。说明种植皇竹草有助于阿特拉津降解效率的提高,且与种植皇竹草后改变了土壤微生物数量及皇竹草的生长状况有关。  相似文献   

11.
通过盆栽试验 ,研究了B、K、Mn、Mg、Zn、Co对青菜中硝酸盐含量的影响。结果表明 :增施硼酸钠后第 2 0天 ,青菜硝酸盐含量比对照降低 1 4 84%~ 1 9 56 % ;增施K、Mn、Mg、Zn、Co也能降低青菜硝酸盐含量。每盆增施0 1gZnSO4 后第 1 0天 ,青菜中硝酸盐含量比对照减少 1 8 96 % ,每盆增施 0 1gK2 SO4 后第 2 0天 ,青菜中硝酸盐含量比对照减少 2 1 42 % ;矿质元素的施用量对青菜硝酸盐含量影响较大。  相似文献   

12.
空气污染是一个全球性的问题,并且具有深远的环境影响。暴露于空气污染会对人体健康产生许多不同的影响,理解空气污染的健康效应又是一个复杂命题,既要考虑不同类型的污染物同时也要考虑相关疾病的复杂性。然而越来越多的研究表明,表观遗传学在空气污染相关疾病的发生、发展中发挥着重要的作用。空气污染物可引起DNA甲基化、组蛋白修饰和miRNA表达等表观遗传学改变,这种改变往往发生在疾病产生的早期,因此相关研究不仅可以了解疾病的发病机制,而且还为疾病早期诊断和预防筛选可能的标志物。本文综述了表观遗传学的几种修饰方式和空气污染物造成不良健康损伤机制的一些研究进展。  相似文献   

13.
Frost PC  Ebert D  Smith VH 《Ecology》2008,89(2):313-318
Host nutrition is thought to affect the establishment, persistence, and severity of pathogenic infections. Nutrient-deficient foods possibly benefit pathogens by constraining host immune function or benefit hosts by limiting parasite growth and reproduction. However, the effects of poor elemental food quality on a host's susceptibility to infection and disease have received little study. Here we show that the bacterial microparasite Pasteuria ramosa is affected by the elemental nutrition of its aquatic invertebrate host, Daphnia magna. We found that high food carbon:phosphorus (C:P) ratios significantly reduced infection rates of Pasteuria in Daphnia and led to lower within-host pathogen multiplication. In addition, greater virulent effects of bacterial infection on host reproduction were found in Daphnia-consuming P-deficient food. Poor Daphnia elemental nutrition thus reduced the growth and reproduction of its bacterial parasite, Pasteuria. The effects of poor host nutrition on the pathogen were further evidenced by Pasteuria's greater inhibition of reproduction in P-limited Daphnia. Our results provide strong evidence that elemental food quality can significantly influence the incidence and intensity of infectious disease in invertebrate hosts.  相似文献   

14.
Abstract:  In the wet tropics of Queensland, Australia, eight species of stream-dwelling frogs have experienced population declines. Some declines were associated with an emerging infectious disease of amphibians (chytridiomycosis) caused by the fungus Batrachochytrium dendrobatidis. We examined the spatial and temporal pattern of infection prevalence in a sample of frog populations. Infected adults and tadpoles of all species were found, and infections occurred at every site. Infection prevalence varied among species and was always < 10.0% in adults but ranged from 0.75 to 76.0% in tadpoles. In this system tadpoles and adults of some species may act as disease reservoirs, experiencing avirulent infections, whereas other hosts (declining species) experience virulent infections. Infection prevalence was higher during the cool, dry winter season (May to September) and at high elevations (600–800 m), suggesting regulation by environmental conditions, including temperature and precipitation. We found no relationships between infection prevalence and mean body condition, fluctuating asymmetry of hind limbs, population density, or the presence of metamorphosing tadpoles and juvenile frogs. Although it is not certain whether chytridiomycosis was responsible for past frog population declines in the wet tropics of Queensland, the pathogen is now endemic. Our data indicate that at the landscape level, environmental conditions have strong effects on host-pathogen dynamics. These effects interact with species-specific behavior or immune function and may be important underlying determinants of chytridiomycosis epizootics and emergence.  相似文献   

15.
阿特拉津对家蚕生殖发育的影响   总被引:4,自引:0,他引:4  
为探讨环境激素(EH)对鳞翅目昆虫的性激素作用,用添加阿特拉津(AT)的人工饲料饲养家蚕,调查AT对家蚕生殖发育的影响.结果显示:1)染毒72、96、120h的半数致死浓度LC50分别为0.348、0.326、0.234mmol·kg-1(即75.1、70.3、50.5mg·kg-1),属中等毒性.2)AT染毒可导致雄性家蚕5龄幼虫生殖腺指数显著升高,成虫(蛾)生殖腺指数显著降低.从整个世代看,0.05mmol·kg-1的AT对家蚕精巢的生长即表现出不良影响.AT染毒对雄蚕5龄幼虫、蛹前期精细胞的形成有促进作用,而对蛹后期和成虫(蛾)的精子形成有限制作用,可能AT染毒阻碍了精细胞向精子的发育.3)雌性家蚕幼虫期AT染毒后,5龄幼虫和蛹的卵细胞数量显著少于对照组(p<0.05).从不同发育时期的影响程度看,AT对卵细胞发育的抑制作用具有显著的时间效应(p<0.05).实验浓度下,AT对雌蚕造卵数和产卵数影响不显著,然而随着AT浓度的增加,不受精卵越来越多,AT染毒对雌蚕受精率具有显著抑制作用.AT通过抑制家蚕生殖腺的生长和生殖细胞的发育表现出雌激素效应.  相似文献   

16.
新型污染物及其生态和环境健康效应   总被引:4,自引:0,他引:4  
近年来,随着现代分析手段的改进和发展,各种污染物检测能力的提高,以及新的毒作用模式的发现、新合成化合物的制造和使用等,一些物质成为广受国内外关注的新型污染物.新型污染物已在世界范围内对环境和生态系统造成了污染,对生态系统中包括人类在内的各种生物均构成了潜在的危害.目前,人们关注较多的新型污染物主要有全氟有机化合物、人用与兽用药物、饮用水消毒副产物、遮光剂/滤紫外线剂、人造纳米材料、汽油添加剂、溴化阻燃剂等.论文在总结国内外相关研究基础上,对一些重点新型污染物的生态效应及其潜在健康影响进行了简要综述,为我国开展这方面的研究提供了一定的参考.  相似文献   

17.
Widespread use of the herbicide atrazine has incited much research on its toxicity in aquatic systems, where it is routinely detected due to runoff from cultivated fields. Moreover, the determination of the genotoxic effect of such pollutants in the marine environment has become a major requirement for ecosystem protection. In the Pacific oyster, Crassostrea gigas, hypodiploid aneuploid cells have regularly been reported. There is a negative correlation between this phenomenon and growth, as well as evidence for a genetic basis. A positive relationship between atrazine and aneuploidy has previously been demonstrated in C. gigas adults and juveniles. To evaluate the persistence of this impact, our study examined the offspring of the same adult population previously treated with different atrazine doses (10 µg l–1, representing a peak value found in a polluted environment and 100 µg l–1), and a seawater control. We observed that these offspring exhibited significantly higher aneuploidy levels when their parents had been exposed to atrazine (14.9–16.9% in comparison with the control where the levels ranged from 11.4% to 12.8%). In addition, the present study examined the aneuploidy level of a sample of juveniles, previously exposed for 3.5 months to the same doses of atrazine, then transferred to non-polluted conditions for an additional period of 2.5 months; this aneuploidy level remained significantly different between the treatments applied. These results demonstrate the persistence of an atrazine impact on Pacific oyster aneuploidy in time, within and between generations, indicating that this widely used compound may represent an important factor causing at least medium-term damage to genetic material.Communicated by S.A. Poulet, Roscoff  相似文献   

18.
内分泌干扰物莠去津对鲫鱼血清激素的影响   总被引:3,自引:1,他引:3  
为了研究低剂量条件下,内分泌干扰物莠去津对鲫鱼血清激素的影响,探讨其作用机理和剂量-效应关系,同时筛选出敏感的生物标志物,实验以除草剂莠去津对鲫鱼进行低剂量染毒(染毒浓度0~3mg·L-1),采用放射免疫法测定莠去津长期暴露下(60d)幼年雄性鲫鱼血清中性激素(17β-雌二醇(E2)、睾酮(T))及甲状腺激素(促甲状腺激素(TSH)、三碘甲状腺原氨酸(T3))的浓度,并将测定结果与空白对照及溶剂对照进行比较.结果发现:1)莠去津长期暴露下,各处理组鲫鱼血清E2浓度普遍升高,0.023、0.094、1.500、3.000mg·L-1组与空白对照相比,升高显著(p<0.05);2)各处理组鲫鱼血清T浓度与空白对照相比均无显著性差异(p>0.05);3)莠去津长期暴露下,低浓度莠去津组(0.006、0.023mg·L-1组)鲫鱼血清TSH浓度与空白对照相比差异不显著(p>0.05),而高浓度莠去津组(0.094、1.500、3.000mg·L-1组)则显著降低(p<0.05);4)类似地,莠去津长期暴露下,低浓度莠去津组(0.006、0.023、0.094、0.375、1.500mg·L-1组)鲫鱼血清T3浓度与空白对照相比差异不显著(p>0.05),只有高浓度莠去津组(3.000mg·L-1组)显著升高(p<0.05).实验结果表明,低剂量长期暴露下,莠去津对鲫鱼体内性激素及甲状腺激素具有一定的干扰作用,尤其是对17β-雌二醇影响更为显著,因此,17β-雌二醇可作为评价农药内分泌干扰效应的生物标志物.  相似文献   

19.
Groundwater is the only source of water in the Gaza Strip. The results of a 10-year monitoring program revealed that more than 90% of the available water is not suitable for drinking purposes as a result of elevated chemical contaminants as well as microbiological organisms. The archives of the local hospitals showed catastrophic records on diseases caused by water directly and indirectly. Methemoglobinemia and dental fluorosis are well-known diseases caused by elevated nitrate and fluoride, respectively. Water-borne diseases are currently high and will increase if water, sanitation, and food-control services are not restored, or are allowed to deteriorate further. Heavy use and misuse of banned and prohibited pesticides may show other hard diseases in the near future. Geography, politics, and war combine to make the Gaza Strip a worst-case scenario for water-resource planners. Urgent alternative water resources should be secured and the human health should be given the highest priority.  相似文献   

20.
Infectious diseases are increasingly recognized as an important force driving population dynamics, conservation biology, and natural selection in wildlife populations. Infectious agents have been implicated in the decline of small or endangered populations and may act to constrain population size, distribution, growth rates, or migration patterns. Further, diseases may provide selective pressures that shape the genetic diversity of populations or species. Thus, understanding disease dynamics and selective pressures from pathogens is crucial to understanding population processes, managing wildlife diseases, and conserving biological diversity. There is ample evidence that variation in the prion protein gene (PRNP) impacts host susceptibility to prion diseases. Still, little is known about how genetic differences might influence natural selection within wildlife populations. Here we link genetic variation with differential susceptibility of white-tailed deer to chronic wasting disease (CWD), with implications for fitness and disease-driven genetic selection. We developed a single nucleotide polymorphism (SNP) assay to efficiently genotype deer at the locus of interest (in the 96th codon of the PRNP gene). Then, using a Bayesian modeling approach, we found that the more susceptible genotype had over four times greater risk of CWD infection; and, once infected, deer with the resistant genotype survived 49% longer (8.25 more months). We used these epidemiological parameters in a multi-stage population matrix model to evaluate relative fitness based on genotype-specific population growth rates. The differences in disease infection and mortality rates allowed genetically resistant deer to achieve higher population growth and obtain a long-term fitness advantage, which translated into a selection coefficient of over 1% favoring the CWD-resistant genotype. This selective pressure suggests that the resistant allele could become dominant in the population within an evolutionarily short time frame. Our work provides a rare example of a quantifiable disease-driven selection process in a wildlife population, demonstrating the potential for infectious diseases to alter host populations. This will have direct bearing on the epidemiology, dynamics, and future trends in CWD transmission and spread. Understanding genotype-specific epidemiology will improve predictive models and inform management strategies for CWD-affected cervid populations.  相似文献   

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