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1.
The Mediterranean fruit fly (medfly) (Ceratitis capitata) lays eggs in fruits, where larvae subsequently develop, causing large-scale agricultural damage. Within its digestive tract, the fly supports an extended bacterial community that is composed of multiple strains of a variety of enterobacterial species. Most of these bacteria appear to be functionally redundant, with most strains sustaining diazotrophy and/or pectinolysis. At least some of these bacteria were shown to be vertically inherited, but colonization, structural, and metabolic aspects of the community''s dynamics have not been investigated. We used fluorescent in situ hybridization, metabolic profiling, plate cultures, and pyrosequencing to show that an initial, egg-borne, diverse community expands throughout the fly''s life cycle. While keeping “core” diazotrophic and pectinolytic functions, it also harbors diverse and fluctuating populations that express varied metabolic capabilities. We suggest that the metabolic and compositional plasticity of the fly''s microbiota provides potential adaptive advantages to the medfly host and that its acquisition and dynamics are affected by mixed processes that include stochastic effects, host behavior, and molecular barriers.  相似文献   

2.

Background

Phylogenetic trees are complex data forms that need to be graphically displayed to be human-readable. Traditional techniques of plotting phylogenetic trees focus on rendering a single static image, but increases in the production of biological data and large-scale analyses demand scalable, browsable, and interactive trees.

Methodology/Principal Findings

We introduce TreeVector, a Scalable Vector Graphics–and Java-based method that allows trees to be integrated and viewed seamlessly in standard web browsers with no extra software required, and can be modified and linked using standard web technologies. There are now many bioinformatics servers and databases with a range of dynamic processes and updates to cope with the increasing volume of data. TreeVector is designed as a framework to integrate with these processes and produce user-customized phylogenies automatically. We also address the strengths of phylogenetic trees as part of a linked-in browsing process rather than an end graphic for print.

Conclusions/Significance

TreeVector is fast and easy to use and is available to download precompiled, but is also open source. It can also be run from the web server listed below or the user''s own web server. It has already been deployed on two recognized and widely used database Web sites.  相似文献   

3.
The degradation of natural forests to modified forests threatens subtropical and tropical biodiversity worldwide. Yet, species responses to forest modification vary considerably. Furthermore, effects of forest modification can differ, whether with respect to diversity components (taxonomic or phylogenetic) or to local (α-diversity) and regional (β-diversity) spatial scales. This real-world complexity has so far hampered our understanding of subtropical and tropical biodiversity patterns in human-modified forest landscapes. In a subtropical South African forest landscape, we studied the responses of three successive plant life stages (adult trees, saplings, seedlings) and of birds to five different types of forest modification distinguished by the degree of within-forest disturbance and forest loss. Responses of the two taxa differed markedly. Thus, the taxonomic α-diversity of birds was negatively correlated with the diversity of all plant life stages and, contrary to plant diversity, increased with forest disturbance. Conversely, forest disturbance reduced the phylogenetic α-diversity of all plant life stages but not that of birds. Forest loss neither affected taxonomic nor phylogenetic diversity of any taxon. On the regional scale, taxonomic but not phylogenetic β-diversity of both taxa was well predicted by variation in forest disturbance and forest loss. In contrast to adult trees, the phylogenetic diversity of saplings and seedlings showed signs of contemporary environmental filtering. In conclusion, forest modification in this subtropical landscape strongly shaped both local and regional biodiversity but with contrasting outcomes. Phylogenetic diversity of plants may be more threatened than that of mobile species such as birds. The reduced phylogenetic diversity of saplings and seedlings suggests losses in biodiversity that are not visible in adult trees, potentially indicating time-lags and contemporary shifts in forest regeneration. The different responses of taxonomic and phylogenetic diversity to forest modifications imply that biodiversity conservation in this subtropical landscape requires the preservation of natural and modified forests.  相似文献   

4.
Understanding the relationships between species,communities,and biodiversity are important challenges in conservation ecology.Current biodiversity conservation activities usually focus on species that are rare,endemic,distinctive,or at risk of extinction.However,empirical studies of whether such species contribute more to aspects of biodiversity than common species are still relatively rare.The aim of the present study was to assess the contribution of individual amphibian species to different facets of biodiversity,and to test whether species of conservation interest contribute more to taxonomic,functional,and phylogenetic diversity than do species without special conservation status.To answer these questions,19 000 simulated random communities with a gradient of species richness were created by shuffling the regional pool of species inhabiting Emei Mountain.Differences of diversity values were then computed before and after removing individual species in these random communities.Our results indicated that although individual species contributed similarly to taxonomic diversity,their contribution to functional and phylogenetic diversity was more idiosyncratic.This was primarily driven by the diverse functional attributes of species and the differences in phylogenetic relationships among species.Additionally,species of conservation interest did not show a significantly higher contribution to any facet of biodiversity.Our results support the claims that the usefulness of metrics based only on species richness is limited.Instead,assemblages that include species with functional and phylogenetic diversity should be protected to maintain biodiversity.  相似文献   

5.
Structural, Functional and Phylogenetic Aspects of the Colleter   总被引:1,自引:1,他引:0  
THOMAS  VINOTH 《Annals of botany》1991,68(4):287-305
This article surveys the structural, functional and phylogeneticsignificance of colleters in different dicotyledonous families.Colleters are multicellular secretory structures attached tothe stipule, petiole, lamina, bract, bracteole, calyx and corolla.Colleters are grouped into standard (S), dendroid (D) and brush-like(B) types on the basis of their morphology and structure. Dand B-type colleters occur in certain members of Rubiaceae thatalso have bacterial leaf nodules. Besides the normal structure,epithelial hairs, thin-walled subepidermal cells, laticifersand vasculature are present in many colleters of Apocynaceae.It is probable that the colleter functions to protect the developingmeristem by secreting a viscous fluid. Exudate of D-type colletersare mucilaginous, providing the substrate necessary for thenutrition of endophytic bacteria. Colleter, structure, phylogeny  相似文献   

6.
7.
Throughout the Amazon region, the age of forests regenerating on previously deforested land is determined, in part, by the periods of active land use prior to abandonment and the frequency of reclearance of regrowth, both of which can be quantified by comparing time-series of Landsat sensor data. Using these time-series of near annual data from 1973–2011 for an area north of Manaus (in Amazonas state), from 1984–2010 for south of Santarém (Pará state) and 1984–2011 near Machadinho d’Oeste (Rondônia state), the changes in the area of primary forest, non-forest and secondary forest were documented from which the age of regenerating forests, periods of active land use and the frequency of forest reclearance were derived. At Manaus, and at the end of the time-series, over 50% of regenerating forests were older than 16 years, whilst at Santarém and Machadinho d’Oeste, 57% and 41% of forests respectively were aged 6–15 years, with the remainder being mostly younger forests. These differences were attributed to the time since deforestation commenced but also the greater frequencies of reclearance of forests at the latter two sites with short periods of use in the intervening periods. The majority of clearance for agriculture was also found outside of protected areas. The study suggested that a) the history of clearance and land use should be taken into account when protecting deforested land for the purpose of restoring both tree species diversity and biomass through natural regeneration and b) a greater proportion of the forested landscape should be placed under protection, including areas of regrowth.  相似文献   

8.
Summary Bumetanide-sensitive Na-K-Cl cotransporters and thiazide-sensitive Na-Cl cotransporters comprise a family of integral membrane transport proteins, the Na-K-Cl cotransporter (NKCC) family. Each of the members of this family is over 1,000 amino acids in length. We have multiply aligned the ten currently sequenced members of this family from human, rabbit, rodent, shark, flounder, moth, worm and yeast sources. Phylogenetic analyses suggest the presence of at least six isoforms of these full length proteins in eukaryotes. Average hydropathy and average similarity plots have been derived revealing that each of these proteins possesses a central, well conserved, hydrophobic domain of almost invariant length, possibly consisting of twelve transmembrane α-helical spanners, an N-terminal, poorly conserved, hydrophilic domain of variable length, and a C-terminal, moderately conserved, hydrophilic domain of moderately constant length. A functionally uncharacterized homologue of this family occurs in the cyanobacterium Synechococcus sp. Limited sequence similarity of these proteins with members of a family of basic amino acid transporters suggests that the NKCC family may be distantly related to the previously characterized, ubiquitous, amino acid-polyamine-choline (APC) family of facilitators. These observations suggest that the NKCC family is an old family that has its roots in the prokaryotic kingdom. Received: 27 July 1995/Revised: 8 November 1995  相似文献   

9.
We evaluated the effect of environmental factors on the abundance and genera richness of aquatic insects colonizing artificial substrates. We also assessed the relative effects of environmental factors on assemblage variation (beta diversity), and contrasted its magnitude with the variation associated with the spatial position of reaches in a Neotropical stream. Homogeneous and heterogeneous bricks were installed in seven stream reaches and removed after 60d. Substrate type and organic matter showed significant effects on abundance. For observed richness, substrate type was the only important variable. For rarefied richness, no explanatory variable was important. A NMDS ordination of bricks revealed the effect of spatial position and substrate type. A partial Redundancy Analysis (pRDA) indicated that the environmental matrix explained 12.44% of the total variation, while reach position explained 7.41%. We conclude that at local scale (reaches 430–920 m apart), environmental factors, especially substrate heterogeneity, were important in determining the alpha and beta diversities of the insect assemblage in the stream (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

10.
11.
Abstract Empirical estimates of the function and resilience of communities under different management regimes can provide valuable information for sustainable natural resource management, but such estimates are scarce to date. We quantified the functional richness and relative resilience of bird communities inhabiting five regions in southeastern Australia that represented different management regimes. First, we show that functional richness and relative resilience were reduced at species-poor sites in all regions. Second, we show that bird communities in agricultural regions had fewer body mass groups and fewer functional groups than expected by chance. This suggests that both the function and the resilience of bird communities in agricultural regions were reduced. The likely mechanisms for the observed loss of function and relative resilience are: (1) the simplification of landscape texture resulting in selective extinction of certain body mass groups; and (2) the selective extinction of certain functional groups that are particularly sensitive to intensive land use. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   

12.
Haa Aani, Our Land: Tlingit and Haida Land Rights and Use. Walter R. Goldschmidt and Theodore H. Haas. edited with an introduction by Thomas F. Thornton. Seattle: University of Washington Press, 1998. 219 pp.  相似文献   

13.
Catchment land uses, particularly agriculture and urban uses, have long been recognized as major drivers of nutrient concentrations in surface waters. However, few simple models have been developed that relate the amount of catchment land use to downstream freshwater nutrients. Nor are existing models applicable to large numbers of freshwaters across broad spatial extents such as regions or continents. This research aims to increase model performance by exploring three factors that affect the relationship between land use and downstream nutrients in freshwater: the spatial extent for measuring land use, hydrologic connectivity, and the regional differences in both the amount of nutrients and effects of land use on them. We quantified the effects of these three factors that relate land use to lake total phosphorus (TP) and total nitrogen (TN) in 346 north temperate lakes in 7 regions in Michigan, USA. We used a linear mixed modeling framework to examine the importance of spatial extent, lake hydrologic class, and region on models with individual lake nutrients as the response variable, and individual land use types as the predictor variables. Our modeling approach was chosen to avoid problems of multi-collinearity among predictor variables and a lack of independence of lakes within regions, both of which are common problems in broad-scale analyses of freshwaters. We found that all three factors influence land use-lake nutrient relationships. The strongest evidence was for the effect of lake hydrologic connectivity, followed by region, and finally, the spatial extent of land use measurements. Incorporating these three factors into relatively simple models of land use effects on lake nutrients should help to improve predictions and understanding of land use-lake nutrient interactions at broad scales.  相似文献   

14.
15.
The present study is the first describing the sequencing of a fragment of the copper-oxidase domain of a laccase gene in the family Botryosphaeriaceae. The aim of this work was to assess the degree of genetic and evolutionary relationships of a laccase gene from Botryosphaeria rhodina MAMB-05 with other ascomycete and basidiomycete laccase genes. The 193-amino acid sequences of the copper-oxidase domain from several different fungi, insects, a plant, and a bacterial species were retrieved from GenBank and aligned. Phylogenetic analyses were performed using neighbor-joining, maximum parsimony, and Bayesian inference methods. The organisms studied clustered into five gene clades: fungi (ascomycetes and basidiomycetes), insects, plants, and bacteria. Also, the topologies showed that fungal laccases of the ascomycetes and basidiomycetes are clearly separated into two distinct clusters. This evidence indicated that B. rhodina MAMB-05 and other closely related ascomycetes are a new biological resource given the biotechnological potential of their laccase genes.  相似文献   

16.
The taxonomy and nomenclature of New World monkeys is becoming precariously unstable and impractical, plagued by revisions aimed at conforming to approaches that reject the Biological Species Concept for narrowly construed reasons and resulting in a hyperinflated taxonomy at species (often) and genus (sometimes) levels. This undermines a major goal of classification at the most basic taxonomic levels to ease communication and facilitate research. Since it is difficult to justify extensive changes in terminology without a deeply justified theoretical purpose or without showing what scientific benefits these alterations can bring, working primatologists need not accept this doctrinaire trend. Knowing as little as we do about what a species actually is, does not justify contorting the value of a species nomenclature so that it reflects nothing more than coat color, a node, or endpoint of a dendrogram. Am. J. Primatol. 74:692‐695, 2012. © 2012 Wiley Periodicals, Inc.  相似文献   

17.
Subsurface sediments of the Sonora Margin (Guaymas Basin), located in proximity of active cold seep sites were explored. The taxonomic and functional diversity of bacterial and archaeal communities were investigated from 1 to 10 meters below the seafloor. Microbial community structure and abundance and distribution of dominant populations were assessed using complementary molecular approaches (Ribosomal Intergenic Spacer Analysis, 16S rRNA libraries and quantitative PCR with an extensive primers set) and correlated to comprehensive geochemical data. Moreover the metabolic potentials and functional traits of the microbial community were also identified using the GeoChip functional gene microarray and metabolic rates. The active microbial community structure in the Sonora Margin sediments was related to deep subsurface ecosystems (Marine Benthic Groups B and D, Miscellaneous Crenarchaeotal Group, Chloroflexi and Candidate divisions) and remained relatively similar throughout the sediment section, despite defined biogeochemical gradients. However, relative abundances of bacterial and archaeal dominant lineages were significantly correlated with organic carbon quantity and origin. Consistently, metabolic pathways for the degradation and assimilation of this organic carbon as well as genetic potentials for the transformation of detrital organic matters, hydrocarbons and recalcitrant substrates were detected, suggesting that chemoorganotrophic microorganisms may dominate the microbial community of the Sonora Margin subsurface sediments.  相似文献   

18.
The population parameters (morphometrics, population size and biomass) were determined for leopard and angulate tortoises in the Thicket Biome, Eastern Cape, South Africa. Leopard tortoises had a mean total length of 306.47mm (SD = 94.65mm, range 59–496mm, n = 89). Males were smaller (mean total length 277.31mm, SD = 71.85mm, range 73–377mm, n = 36) than females (mean total length = 332.33mm, SD = 97.64mm, range 59–496mm, n = 53). Angulate tortoises had a mean total length of 155.17mm (SD = 33.89mm, range 59–194mm, n = 18). Males were larger (mean total length = 186mm, SD = 8.40mm, range 174–194mm, n = 5) than females (mean total length = 143.31mm, SD = 32.48mm, range 59–178mm, n = 13). The estimated population density for leopard tortoises was 0.85 tortoises ha−1 with an estimated biomass of 6.02kg −1. Angulate tortoise population density was estimated at 0.12 tortoises ha−1 with a mean biomass of 0.06kg ha−1. The possible consequences of this high density and biomass are discussed.  相似文献   

19.
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Highlights
  • •The gut mucosal-luminal interface is a spatiotemporal heterogeneous ecosystem.
  • •Proteomics and metaproteomics are tools to study the host and microbiome functionality.
  • •Insights into functional diversity, biomass, and matter flow can be obtained.
  • •Such data can be complementary inputs for building ecology models of the microbiome.
  相似文献   

20.
In general, community similarity is thought to decay with distance; however, this view may be complicated by the relative roles of different ecological processes at different geographical scales, and by the compositional perspective (e.g. species, functional group and phylogenetic lineage) used. Coastal salt marshes are widely distributed worldwide, but no studies have explicitly examined variation in salt marsh plant community composition across geographical scales, and from species, functional and phylogenetic perspectives. Based on studies in other ecosystems, we hypothesized that, in coastal salt marshes, community turnover would be more rapid at local versus larger geographical scales; and that community turnover patterns would diverge among compositional perspectives, with a greater distance decay at the species level than at the functional or phylogenetic levels. We tested these hypotheses in salt marshes of two regions: The southern Atlantic and Gulf Coasts of the United States. We examined the characteristics of plant community composition at each salt marsh site, how community similarity decayed with distance within individual salt marshes versus among sites in each region, and how community similarity differed among regions, using species, functional and phylogenetic perspectives. We found that results from the three compositional perspectives generally showed similar patterns: there was strong variation in community composition within individual salt marsh sites across elevation; in contrast, community similarity decayed with distance four to five orders of magnitude more slowly across sites within each region. Overall, community dissimilarity of salt marshes was lowest on the southern Atlantic Coast, intermediate on the Gulf Coast, and highest between the two regions. Our results indicated that local gradients are relatively more important than regional processes in structuring coastal salt marsh communities. Our results also suggested that in ecosystems with low species diversity, functional and phylogenetic approaches may not provide additional insight over a species-based approach.  相似文献   

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