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221.
Sergios-Orestis Kolokotronis Ross DE MacPhee Alex D Greenwood 《BMC evolutionary biology》2007,7(1):67
Background
Nuclear insertions of mitochondrial sequences (NuMts) have been identified in a wide variety of organisms. Trafficking of genetic material from the mitochondria to the nucleus has occurred frequently during mammalian evolution and can lead to the production of a large pool of sequences with varying degrees of homology to organellar mitochondrial DNA (mtDNA) sequences. This presents both opportunities and challenges for forensics, population genetics, evolutionary genetics, conservation biology and the study of DNA from ancient samples. Here we present a case in which difficulties in ascertaining the organellar mtDNA sequence from modern samples hindered their comparison to ancient DNA sequences. 相似文献222.
1. Interactions between species can vary from mutually beneficial to evolutionarily neutral to antagonistic, even when the same two species are involved. Similarly, social interactions between members of the same species can lie on a spectrum from conflict to cooperation. 2. The aim of the present study was to investigate whether variation in the two types of social behaviour are interconnected. Is the fitness of the various classes of social partner within species (such as parent and offspring, or male and female) differently affected by interactions with a second species? Moreover, can inter‐specific interactions influence the outcome of social interactions within species? 3. The present experiments focus on the interactions between the burying beetle Nicrophorus vespilloides Herbst and the phoretic mite Poecilochirus carabi G. Canestrini & R. Canestrini. The approach was to measure the fitness of burying beetle mothers, fathers, and offspring after reproduction, which took place either in the presence or absence of mites. 4. We found that male, female, and larval burying beetles derive contrasting fitness costs and benefits from their interactions with the mite, despite sharing a common family environment. From the mite's perspective, its relationship with the burying beetle can, therefore, be simultaneously antagonistic, neutral, and possibly even mutualistic, depending on the particular family member involved. We also found that mites can potentially change the outcome of evolutionary conflicts within the family. 5. We conclude that inter‐specific interactions can explain some of the variation in social interactions seen within species. It is further suggested that intra‐specific interactions might contribute to variation in the outcome of interactions between species. 相似文献
223.
The auxin response factor,OsARF19, controls rice leaf angles through positively regulating OsGH3‐5 and OsBRI1 下载免费PDF全文
SAINA ZHANG SUIKANG WANG YANXIA XU CHENLIANG YU CHENJIA SHEN QIAN QIAN MARKUS GEISLER DE AN JIANG YANHUA QI 《Plant, cell & environment》2015,38(4):638-654
Auxin and brassinosteroid (BR) are important phytohormones for controlling lamina inclination implicated in plant architecture and grain yield. But the molecular mechanism of auxin and BR crosstalk for regulating lamina inclination remains unknown. Auxin response factors (ARFs) control various aspects of plant growth and development. We here report that OsARF19‐overexpression rice lines show an enlarged lamina inclination due to increase of its adaxial cell division. OsARF19 is expressed in various organs including lamina joint and strongly induced by auxin and BR. Chromatin immunoprecipitation (ChIP) and yeast one‐hybrid assays demonstrate that OsARF19 binds to the promoter of OsGH3‐5 and brassinosteroid insensitive 1 (OsBRI1) directing their expression. OsGH3‐5‐overexpression lines show a similar phenotype as OsARF19‐O1. Free auxin contents in the lamina joint of OsGH3‐5‐O1 or OsARF19‐O1 are reduced. OsGH3‐5 is localized at the endoplasmic retieulum (ER) matching reduction of the free auxin contents in OsGH3‐5‐O1. osarf19‐TDNA and osgh3‐5‐Tos17 mutants without erected leaves show a function redundancy with other members of their gene family. OsARF19‐overexpression lines are sensitive to exogenous BR treatment and alter the expressions of genes related to BR signalling. These findings provide novel insights into auxin and BR signalling, and might have significant implications for improving plant architecture of monocot crops. 相似文献
224.
Quantitative trait loci and candidate genes underlying genotype by environment interaction in the response of Arabidopsis thaliana to drought 下载免费PDF全文
MOHAMED EL‐SODA WILLEM KRUIJER MARCOS MALOSETTI MAARTEN KOORNNEEF MARK G. M. AARTS 《Plant, cell & environment》2015,38(3):585-599
Drought stress was imposed on two sets of Arabidopsis thaliana genotypes grown in sand under short‐day conditions and analysed for several shoot and root growth traits. The response to drought was assessed for quantitative trait locus (QTL) mapping in a genetically diverse set of Arabidopsis accessions using genome‐wide association (GWA) mapping, and conventional linkage analysis of a recombinant inbred line (RIL) population. Results showed significant genotype by environment interaction (G×E) for all traits in response to different watering regimes. For the RIL population, the observed G×E was reflected in 17 QTL by environment interactions (Q×E), while 17 additional QTLs were mapped not showing Q×E. GWA mapping identified 58 single nucleotide polymorphism (SNPs) associated with loci displaying Q×E and an additional 16 SNPs associated with loci not showing Q×E. Many candidate genes potentially underlying these loci were suggested. The genes for RPS3C and YLS7 were found to contain conserved amino acid differences when comparing Arabidopsis accessions with strongly contrasting drought response phenotypes, further supporting their candidacy. One of these candidate genes co‐located with a QTL mapped in the RIL population. 相似文献
225.
Predators marked with chemical cues from one prey have increased attack success on another prey species 下载免费PDF全文
GEORGE BROUFAS PAULIEN DE JONG ERNESTINA AGUILAR‐FENOLLOSA ALEXANDRA REVYNTHI MAURICE W. SABELIS ARNE JANSSEN 《Ecological Entomology》2015,40(1):62-68
1. To reduce the risk of being eaten by predators, prey alter their morphology or behaviour. This response can be tuned to the current danger if chemical or other cues associated with predators inform the prey about the risks involved. 2. It is well known that various prey species discriminate between chemical cues from predators that fed on conspecific prey and those that fed on heterospecific prey, and react stronger to the first. It is therefore expected that generalist predators are more successful in capturing a given prey species when they are contaminated with chemical cues from another prey species instead of cues from the same prey species. 3. Here, a generalist predatory mite was studied that feeds on thrips larvae as well as on whitefly eggs and crawlers. Mites were marked with cues (i.e. body fluids) of one of these two prey species and were subsequently offered thrips larva. 4. Predators marked with thrips cues killed significantly fewer thrips than predators marked with whitefly cues, even though the predator's tendency to attack was the same. In addition, more thrips larvae sought refuge in the presence of a predatory mite marked with thrips cues instead of whitefly cues. 5. This suggests that generalist predators may experience improved attack success when switching prey species. 相似文献
226.
线叶嵩草草地群落构成及种间关联分析 总被引:1,自引:0,他引:1
以线叶嵩草群落和退化的线叶嵩草群落为对象,采用方差比率法分析群落总体关联性;基于2×2列联表及植物种重要值,运用χ2检验和Jaccard指数及Spearman秩相关分析,探讨了群落构成、植物种间关系及群落演替的阶段。结果表明:(1)2个群落物种组成差异小;(2)群落总体关联性均为显著负相关,群落种间关系整体上比较紧密;(3)群落内多数物种间联结性较弱,独立性较强,呈正相关和负相关的种对数约各占一半。研究认为,2个线叶嵩草群落均处于不稳定阶段。 相似文献
227.
228.
BELINDA E. MEDLYN REMKO A. DUURSMA DEREK EAMUS DAVID S. ELLSWORTH I. COLIN PRENTICE CRAIG V. M. BARTON KRISTINE Y. CROUS PAOLO DE ANGELIS MICHAEL FREEMAN LISA WINGATE 《Global Change Biology》2011,17(6):2134-2144
Models of vegetation function are widely used to predict the effects of climate change on carbon, water and nutrient cycles of terrestrial ecosystems, and their feedbacks to climate. Stomatal conductance, the process that governs plant water use and carbon uptake, is fundamental to such models. In this paper, we reconcile two long‐standing theories of stomatal conductance. The empirical approach, which is most commonly used in vegetation models, is phenomenological, based on experimental observations of stomatal behaviour in response to environmental conditions. The optimal approach is based on the theoretical argument that stomata should act to minimize the amount of water used per unit carbon gained. We reconcile these two approaches by showing that the theory of optimal stomatal conductance can be used to derive a model of stomatal conductance that is closely analogous to the empirical models. Consequently, we obtain a unified stomatal model which has a similar form to existing empirical models, but which now provides a theoretical interpretation for model parameter values. The key model parameter, g1, is predicted to increase with growth temperature and with the marginal water cost of carbon gain. The new model is fitted to a range of datasets ranging from tropical to boreal trees. The parameter g1 is shown to vary with growth temperature, as predicted, and also with plant functional type. The model is shown to correctly capture responses of stomatal conductance to changing atmospheric CO2, and thus can be used to test for stomatal acclimation to elevated CO2. The reconciliation of the optimal and empirical approaches to modelling stomatal conductance is important for global change biology because it provides a simple theoretical framework for analyzing, and simulating, the coupling between carbon and water cycles under environmental change. 相似文献
229.
The simultaneous study of the temporal dynamics of foraging behaviour, diet and seed abundance is essential to assess the way in which resources affect the behaviour and ecology of harvester ants. Here, we evaluate how fluctuations in grass seed abundance during three consecutive growing seasons influenced the foraging behaviour and diet of the harvester ants Pogonomyrmex rastratus, P. mendozanus and P. inermis in the central Monte desert, Argentina. Seed abundance of the most consumed grasses varied greatly through ant activity season, and ants altered their foraging behaviour in response to those changes. Foragers spent more time travelling and searching for food, and their foraging trips took longer during the low seed availability season. Foraging distance was very similar among species and, contrary to our expectations, did not vary between seasons. Foraging success of P. rastratus and P. inermis increased during the high availability season. This matched the seasonal pattern of foraging activity, suggesting that colonies may detect seed abundance and regulate their foraging effort with the rate of forager success. Although grass seeds were the main item in the diet of the three species, P. mendozanus, and to a lesser extent P. rastratus, turned more generalist when grass seeds were scarce. In contrast, P. inermis showed a very narrow diet breadth, only harvesting grass seeds in both seasons. Our results indicate the relevance of seed availability on foraging behaviour of harvester ants, which should be taken into account when predicting and evaluating the effect of ants on seed resources as well as numerical responses of harvester ant populations to the temporal and spatial variations in grass seed abundance. 相似文献