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Joseph R. Hoyt Kate E. Langwig Keping Sun Guanjun Lu Katy L. Parise Tinglei Jiang Winifred F. Frick Jeffrey T. Foster Jiang Feng A. Marm Kilpatrick 《Proceedings. Biological sciences / The Royal Society》2016,283(1826)
Predicting species'' fates following the introduction of a novel pathogen is a significant and growing problem in conservation. Comparing disease dynamics between introduced and endemic regions can offer insight into which naive hosts will persist or go extinct, with disease acting as a filter on host communities. We examined four hypothesized mechanisms for host–pathogen persistence by comparing host infection patterns and environmental reservoirs for Pseudogymnoascus destructans (the causative agent of white-nose syndrome) in Asia, an endemic region, and North America, where the pathogen has recently invaded. Although colony sizes of bats and hibernacula temperatures were very similar, both infection prevalence and fungal loads were much lower on bats and in the environment in Asia than North America. These results indicate that transmission intensity and pathogen growth are lower in Asia, likely due to higher host resistance to pathogen growth in this endemic region, and not due to host tolerance, lower transmission due to smaller populations, or lower environmentally driven pathogen growth rate. Disease filtering also appears to be favouring initially resistant species in North America. More broadly, determining the mechanisms allowing species persistence in endemic regions can help identify species at greater risk of extinction in introduced regions, and determine the consequences for disease dynamics and host–pathogen coevolution. 相似文献
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三七根腐病原菌毁坏柱孢霉分子定量检测方法及其应用 总被引:1,自引:0,他引:1
【目的】建立一种快速准确的三七根腐病病原真菌毁坏柱孢霉(Cylindrocarpon destructans)的分子定量检测方法,探讨毁坏柱孢霉与植株生长和AM真菌侵染之间的数量效应关系。【方法】根据GenBank登录的毁坏柱孢霉rDNA基因IGS序列片段,设计特异性引物对CDU2和CDL2b,利用含有SYBR Green I的实时荧光定量PCR建立毁坏柱孢霉定量检测方法,检测三七根际土壤毁坏柱孢霉rDNA基因IGS片段拷贝数,并分析其与植株生物量和AM真菌侵染之间的关系。【结果】发病植株根际土壤毁坏柱孢霉rDNA基因IGS片段拷贝数显著高于健康植株。三七根际土壤中毁坏柱孢霉数量与植株地上部生物量以及菌根侵染强度呈显著负相关(P<0.05),与根系生物量以及根内丛枝丰度相关性不显著。【结论】基于实时定量PCR技术建立的毁坏柱孢霉的分子定量方法能够有效反映三七根际土壤中毁坏柱孢霉的数量及其与植株生长和AM真菌侵染的关系。 相似文献
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Y. DALPÉ 《The New phytologist》1989,113(4):523-527
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Catherine G. Haase Nathan W. Fuller Yvonne A. Dzal C. Reed Hranac David T. S. Hayman Cori L. Lausen Kirk A. Silas Sarah H. Olson Raina K. Plowright 《Ecology and evolution》2021,11(1):506-515
In multihost disease systems, differences in mortality between species may reflect variation in host physiology, morphology, and behavior. In systems where the pathogen can persist in the environment, microclimate conditions, and the adaptation of the host to these conditions, may also impact mortality. White‐nose syndrome (WNS) is an emerging disease of hibernating bats caused by an environmentally persistent fungus, Pseudogymnoascus destructans. We assessed the effects of body mass, torpid metabolic rate, evaporative water loss, and hibernaculum temperature and water vapor deficit on predicted overwinter survival of bats infected by P. destructans. We used a hibernation energetics model in an individual‐based model framework to predict the probability of survival of nine bat species at eight sampling sites across North America. The model predicts time until fat exhaustion as a function of species‐specific host characteristics, hibernaculum microclimate, and fungal growth. We fit a linear model to determine relationships with each variable and predicted survival and semipartial correlation coefficients to determine the major drivers in variation in bat survival. We found host body mass and hibernaculum water vapor deficit explained over half of the variation in survival with WNS across species. As previous work on the interplay between host and pathogen physiology and the environment has focused on species with narrow microclimate preferences, our view on this relationship is limited. Our results highlight some key predictors of interspecific survival among western bat species and provide a framework to assess impacts of WNS as the fungus continues to spread into western North America. 相似文献
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[目的]以纤维素为唯一碳源,从四川省阿坝自治州黄龙沟的高山低温环境中分离筛选产纤维素酶的耐冷菌,并研究菌株的产酶特征.[方法]根据菌株的ITS序列分析及形态特征,对菌株进行鉴定.利用DNS法测定纤维素酶酶活性.[结果]从四川省阿坝自治州黄龙沟的高山腐殖土中筛选出一株产纤维素酶的耐冷菌HD1031,经鉴定该菌为玫红假裸囊菌(Pseudogymnoascus roseus).该菌可在4℃-25℃生长,最适生长温度为16℃-17℃.该菌在以微晶纤维素和玉米芯粉为碳源、硫酸铵和Tryptone为氮源的培养基中,17℃、160 r/min摇瓶发酵8d后产生纤维素酶,其中内切葡聚糖酶酶活为366.67 U/mL,滤纸酶酶活87.6 U/mL,β-葡萄糖苷酶酶活90.8 U/mL,酶最适反应pH为6.0,最适反应温度为50℃.[结论]筛选获得一株产纤维素酶的耐冷菌HD1031,此菌株所产纤维素酶在20℃-40℃下活性较高,对热敏感,具有低温纤维素酶的特点. 相似文献
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We document white‐nose syndrome (WNS), a lethal disease of bats caused by the fungus Pseudogymnoascus destructans (Pd), and hibernacula microclimate in New Brunswick, Canada. Our study area represents a more northern region than is common for hibernacula microclimate investigations, providing insight as to how WNS may impact bats at higher latitudes. To determine the impact of the March 2011 arrival of Pd in New Brunswick and the role of hibernacula microclimate on overwintering bat mortality, we surveyed bat numbers at hibernacula twice a year from 2009 to 2015. We also collected data from iButton temperature loggers deployed at all sites and data from HOBO temperature and humidity loggers at three sites. Bat species found in New Brunswick hibernacula include Myotis lucifugus (Little Brown Bat) and M. septentrionalis (Northern Long‐eared Bat), with small numbers of Perimyotis subflavus (Tricolored Bat). All known hibernacula in the province were Pd‐positive with WNS‐positive bats by winter 2013. A 99% decrease in the overwintering bat population in New Brunswick was observed between 2011 and 2015. We did not observe P. subflavus during surveys 2013–2015 and the species appears to be extirpated from these sites. Bats did not appear to choose hibernacula based on winter temperatures, but dark zone (zone where no light penetrates) winter temperatures did not differ among our study sites. Winter dark zone temperatures were warmer and less variable than entrance or above ground temperatures. We observed visible Pd growth on hibernating bats in New Brunswick during early winter surveys (November), even though hibernacula temperatures were colder than optimum for in vitro Pd growth. This suggests that cold hibernacula temperatures encountered near the apparent northern range limit for Pd do not sufficiently slow fungal growth to prevent the onset of WNS and associated bat mortality over the winter. 相似文献
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Winifred F. Frick Sébastien J. Puechmaille Joseph R. Hoyt Barry A. Nickel Kate E. Langwig Jeffrey T. Foster Kate E. Barlow Tomáš Bartonička Dan Feller Anne‐Jifke Haarsma Carl Herzog Ivan Horáček Jeroen van der Kooij Bart Mulkens Boyan Petrov Rick Reynolds Luísa Rodrigues Craig W. Stihler Gregory G. Turner A. Marm Kilpatrick 《Global Ecology and Biogeography》2015,24(7):741-749
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Xueling Yi Deahn M. Donner Paula E. Marquardt Jonathan M. Palmer Michelle A. Jusino Jacqueline Frair Daniel L. Lindner Emily K. Latch 《Ecology and evolution》2020,10(18):10031-10043
White‐nose syndrome (WNS), caused by the fungal pathogen Pseudogymnoascus destructans (Pd), has driven alarming declines in North American hibernating bats, such as little brown bat (Myotis lucifugus). During hibernation, infected little brown bats are able to initiate anti‐Pd immune responses, indicating pathogen‐mediated selection on the major histocompatibility complex (MHC) genes. However, such immune responses may not be protective as they interrupt torpor, elevate energy costs, and potentially lead to higher mortality rates. To assess whether WNS drives selection on MHC genes, we compared the MHC DRB gene in little brown bats pre‐ (Wisconsin) and post‐ (Michigan, New York, Vermont, and Pennsylvania) WNS (detection spanning 2014–2015). We genotyped 131 individuals and found 45 nucleotide alleles (27 amino acid alleles) indicating a maximum of 3 loci (1–5 alleles per individual). We observed high allelic admixture and a lack of genetic differentiation both among sampling sites and between pre‐ and post‐WNS populations, indicating no signal of selection on MHC genes. However, post‐WNS populations exhibited decreased allelic richness, reflecting effects from bottleneck and drift following rapid population declines. We propose that mechanisms other than adaptive immunity are more likely driving current persistence of little brown bats in affected regions. 相似文献