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1.
Variation in heat-shock proteins among species of desert fishes (Poeciliidae, Poeciliopsis) 总被引:4,自引:0,他引:4
Analysis of the heat-shock proteins (hsps) of six closely related species
of Poeciliopsis demonstrated the existence of biochemical diversity in the
hsp100, hsp70, hsp60, and hsp30 protein families among species. Each
species expressed five to seven hsp70-related isoforms. Constitutive 70-kD
isoforms were identical among species, but four different patterns of
heat-inducible isoforms were seen in these six species. Members of the
hsp70 family of molecular chaperones are included among the most highly
conserved proteins known, and the possibility of variation in hsp70 among
closely related species has rarely been addressed. The hsp30 family is
known to be less conserved than the hsp70 family, and, as expected, the
Poeciliopsis hsp30 patterns showed more variation. Most of the hsp30
isoforms characteristic of a particular species were unique to that
species. Hsp100 and hsp60 were identical in five of the species, but
alternate isoforms were found in P. monacha. The small size and limited
geographical distribution of the P. monacha population have probably
contributed to the uniqueness of the monacha pattern. Two of the species
were shown to acquire thermotolerance, the ability to withstand normally
lethal temperatures when subjected to a gradual temperature increase.
Rapid-heating protocols commonly used to establish critical thermal maxima
of organisms do not include this inducible component of thermoresistance
and therefore do not adequately assess an organism's capacity to withstand
thermal stress.
相似文献
2.
Many species are shifting their distributions due to climate change and to increasing international trade that allows dispersal of individuals across the globe. In the case of agricultural pests, such range shifts may heavily impact agriculture. Species distribution modelling may help to predict potential changes in pest distributions. However, these modelling strategies are subject to large uncertainties coming from different sources. Here we used the case of the tomato red spider mite (Tetranychus evansi), an invasive pest that affects some of the most important agricultural crops worldwide, to show how uncertainty may affect forecasts of the potential range of the species. We explored three aspects of uncertainty: (1) species prevalence; (2) modelling method; and (3) variability in environmental responses between mites belonging to two invasive clades of T. evansi. Consensus techniques were used to forecast the potential range of the species under current and two different climate change scenarios for 2080, and variance between model projections were mapped to identify regions of high uncertainty. We revealed large predictive variations linked to all factors, although prevalence had a greater influence than the statistical model once the best modelling strategies were selected. The major areas threatened under current conditions include tropical countries in South America and Africa, and temperate regions in North America, the Mediterranean basin and Australia. Under future scenarios, the threat shifts towards northern Europe and some other temperate regions in the Americas, whereas tropical regions in Africa present a reduced risk. Analysis of niche overlap suggests that the current differential distribution of mites of the two clades of T. evansi can be partially attributed to environmental niche differentiation. Overall this study shows how consensus strategies and analysis of niche overlap can be used jointly to draw conclusions on invasive threat considering different sources of uncertainty in species distribution modelling. 相似文献
3.
High throughput T-DNA insertion mutagenesis in rice: a first step towards in silico reverse genetics 总被引:23,自引:0,他引:23
4.
The virtual ecologist approach: simulating data and observers 总被引:3,自引:0,他引:3
Damaris Zurell Uta Berger Juliano S. Cabral Florian Jeltsch Christine N. Meynard Tamara Münkemüller Nana Nehrbass Jörn Pagel Björn Reineking Boris Schröder Volker Grimm 《Oikos》2010,119(4):622-635
Ecologists carry a well‐stocked toolbox with a great variety of sampling methods, statistical analyses and modelling tools, and new methods are constantly appearing. Evaluation and optimisation of these methods is crucial to guide methodological choices. Simulating error‐free data or taking high‐quality data to qualify methods is common practice. Here, we emphasise the methodology of the ‘virtual ecologist’ (VE) approach where simulated data and observer models are used to mimic real species and how they are ‘virtually’ observed. This virtual data is then subjected to statistical analyses and modelling, and the results are evaluated against the ‘true’ simulated data. The VE approach is an intuitive and powerful evaluation framework that allows a quality assessment of sampling protocols, analyses and modelling tools. It works under controlled conditions as well as under consideration of confounding factors such as animal movement and biased observer behaviour. In this review, we promote the approach as a rigorous research tool, and demonstrate its capabilities and practical relevance. We explore past uses of VE in different ecological research fields, where it mainly has been used to test and improve sampling regimes as well as for testing and comparing models, for example species distribution models. We discuss its benefits as well as potential limitations, and provide some practical considerations for designing VE studies. Finally, research fields are identified for which the approach could be useful in the future. We conclude that VE could foster the integration of theoretical and empirical work and stimulate work that goes far beyond sampling methods, leading to new questions, theories, and better mechanistic understanding of ecological systems. 相似文献
5.
In clinical neurology, a comprehensive understanding of consciousness has been regarded as an abstract concept - best left
to philosophers. However, times are changing and the need to clinically assess consciousness is increasingly becoming a real-world,
practical challenge. Current methods for evaluating altered levels of consciousness are highly reliant on either behavioural
measures or anatomical imaging. While these methods have some utility, estimates of misdiagnosis are worrisome (as high as
43%) - clearly this is a major clinical problem. The solution must involve objective, physiologically based measures that
do not rely on behaviour. This paper reviews recent advances in physiologically based measures that enable better evaluation
of consciousness states (coma, vegetative state, minimally conscious state, and locked in syndrome). Based on the evidence
to-date, electroencephalographic and neuroimaging based assessments of consciousness provide valuable information for evaluation
of residual function, formation of differential diagnoses, and estimation of prognosis. 相似文献
6.
Carolina Camus Andrs P. Meynard Sylvain Faugeron Kazuhiro Kogame Juan A. Correa 《Journal of phycology》2005,41(5):931-941
The identity of two phaeophycean taxa that monopolized the middle‐lower rocky intertidal zone of a coastal area chronically exposed to copper mine wastes in northern Chile was unraveled. One of them was preliminarily identified as the gametophytic stage of Scytosiphon lomentaria (Lyngbye) Link. The other, a dark crust, resembled the alternate stage of some Scytosiphon species. Comparative analysis of morphology, life history, and DNA sequences strongly suggests that crusts corresponded to sporophytic S. tenellus Kogame and confirm that erect thalli belonged to S. lomentaria. A clear segregation of erect and crustose thalli was found using internal transcribed spacer region 1 and RUBISCO spacer sequences. Furthermore, whereas crusts always grouped with S. tenellus, erect thalli always grouped with S. lomentaria. Life history studies failed to connect the two entities. First, field‐collected S. tenellus produced progeny that either recycled the crust, which reproduced by unilocular zoidangia, or developed into erect thalli. The latter, unlike typical gametophytic S. lomentaria, developed patchy sori of plurilocular zoidangia. Second, S. lomentaria displayed a direct‐type life cycle, in which progeny from erect individuals only developed into erect thalli and produced only plurilocular zoidangia. This constitutes the first experimental study on Scytosiphon from the Pacific coast of South America and the first report of S. tenellus on this coast. It is also the first report of the crustose stage of Scytosiphon appearing as a perennial and dominant algal species in a temperate rocky intertidal system. 相似文献
7.
Puroindolines form the molecular basis of wheat grain hardness. However, little is known about puroindoline gene regulation.
We previously reported that the Triticum aestivum puroindoline-b gene (PinB) promoter directs β-glucuronidase gene (uidA) seed-specific expression in transgenic rice. In this study, we isolated a puroindoline-a gene (PinA), analyzed PinA promoter activity by 5′ deletions and compared PinA and PinB promoters in transgenic rice. Seeds of PinA-1214 and PinB-1063 transgenic plants strongly expressed uidA in endosperm, in the aleurone layer and in epidermis cells in a developmentally regulated manner. The GUS activity was also
observed in PinA-1214 embryos. Whereas the PinB promoter is seed specific, the PinA promoter also directed, but to a lower level, uidA expression in roots of seedlings and in the vascular tissues of palea and pollen grains of dehiscent anthers during flower
development. In addition, the PinA promoter was induced by wounding and by Magnaporthe grisea. By deletion analysis, we showed that the “390-bp” PinA promoter drives the same expression pattern as the “1214-bp” promoter. Moreover, the “214-bp” PinA promoter drives uidA expression solely in pollen grains of dehiscent anthers. The presence of putative cis-regulatory elements that may be related to PinA expression is discussed from an evolutionary point of view. By electrophoretic mobility shift assay, we showed that putative
cis-elements (WUN-box, TCA motifs and as-1-like binding sites) whose presence in the PinA promoter may be related to wounding and/or the pathogen response form complexes with nuclear extracts isolated from wounded
wheat leaves. 相似文献
8.
Giang Ngan Khong Pratap Kumar Pati Frédérique Richaud Boris Parizot Przemyslaw Bidzinski Chung Duc Mai Martine Bès Isabelle Bourrié Donaldo Meynard Tom Beeckman Michael Gomez Selvaraj Ishitani Manabu Anna-Maria Genga Christophe Brugidou Vinh Nang Do Emmanuel Guiderdoni Jean-Benoit Morel Pascal Gantet 《Plant physiology》2015,169(4):2935-2949
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10.
Meynard JB Flamand C Dupuy C Mahamat A Eltges F Queuche F Renner J Fontanella JM Hommel D Dussart P Grangier C Djossou F Dacheux L Goudal M Berger F Ardillon V Krieger N Bourhy H Spiegel A 《PLoS neglected tropical diseases》2012,6(2):e1537