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31.
D. Y. Sumner A. D. Jungblut I. Hawes D. T. Andersen T. J. Mackey K. Wall 《Geobiology》2016,14(6):556-574
Microbial pinnacles in ice‐covered Lake Vanda, McMurdo Dry Valleys, Antarctica, extend from the base of the ice to more than 50 m water depth. The distribution of microbial communities, their photosynthetic potential, and pinnacle morphology affects the local accumulation of biomass, which in turn shapes pinnacle morphology. This feedback, plus environmental stability, promotes the growth of elaborate microbial structures. In Lake Vanda, all mats sampled from greater than 10 m water depth contained pinnacles with a gradation in size from <1‐mm‐tall tufts to pinnacles that were centimeters tall. Small pinnacles were cuspate, whereas larger ones had variable morphology. The largest pinnacles were up to ~30 cm tall and had cylindrical bases and cuspate tops. Pinnacle biomass was dominated by cyanobacteria from the morphological and genomic groups Leptolyngbya, Phormidium, and Tychonema. The photosynthetic potential of these cyanobacterial communities was high to depths of several millimeters into the mat based on PAM fluorometry, and sufficient light for photosynthesis penetrated ~5 mm into pinnacles. The distribution of photosynthetic potential and its correlation to pinnacle morphology suggests a working model for pinnacle growth. First, small tufts initiate from random irregularities in prostrate mat. Some tufts grow into pinnacles over the course of ~3 years. As pinnacles increase in size and age, their interiors become colonized by a more diverse community of cyanobacteria with high photosynthetic potential. Biomass accumulation within this subsurface community causes pinnacles to swell, expanding laminae thickness and creating distinctive cylindrical bases and cuspate tops. This change in shape suggests that pinnacle morphology emerges from a specific distribution of biomass accumulation that depends on multiple microbial communities fixing carbon in different parts of pinnacles. Similarly, complex patterns of biomass accumulation may be reflected in the morphology of elaborate ancient stromatolites. 相似文献
32.
Emily D. Matys Tyler Mackey Christen Grettenberger Elliott Mueller Anne Jungblut Dawn Y. Sumner Ian Hawes Roger E. Summons 《Geobiology》2019,17(5):551-563
Bacteriohopanepolyols (BHPs) are pentacyclic triterpenoid lipids that contribute to the structural integrity and physiology of some bacteria. Because some BHPs originate from specific classes of bacteria, BHPs have potential as taxonomically and environmentally diagnostic biomarkers. For example, a stereoisomer of bacteriohopanetetrol (informally BHT II) has been associated with anaerobic ammonium oxidation (anammox) bacteria and suboxic to anoxic marine environments where anammox is active. As a result, the detection of BHT II in the sedimentary record and fluctuations in the relative abundance of BHT II may inform reconstructions of nitrogen cycling and ocean redox changes through the geological record. However, there are uncertainties concerning the sources of BHT II and whether or not BHT II is produced in abundance in non‐marine environments, both of which are pertinent to interpretations of BHT II signatures in sediments. To address these questions, we investigate the BHP composition of benthic microbial mats from Lake Fryxell, Antarctica. Lake Fryxell is a perennially ice‐covered lake with a sharp oxycline in a density‐stabilized water column. We describe the diversity and abundance of BHPs in benthic microbial mats across a transect from oxic to anoxic conditions. Generally, BHP abundances and diversity vary with the morphologies of microbial mats, which were previously shown to reflect local environmental conditions, such as irradiance and oxygen and sulfide concentrations. BHT II was identified in mats that exist within oxic to anoxic portions of the lake. However, anammox bacteria have yet to be identified in Lake Fryxell. We examine our results in the context of BHPs as biomarkers in modern and ancient environments. 相似文献
33.
Proposed minimum reporting standards for chemical analysis 总被引:4,自引:0,他引:4
Lloyd W. Sumner Alexander Amberg Dave Barrett Michael H. Beale Richard Beger Clare A. Daykin Teresa W.-M. Fan Oliver Fiehn Royston Goodacre Julian L. Griffin Thomas Hankemeier Nigel Hardy James Harnly Richard Higashi Joachim Kopka Andrew N. Lane John C. Lindon Philip Marriott Andrew W. Nicholls Michael D. Reily John J. Thaden Mark R. Viant 《Metabolomics : Official journal of the Metabolomic Society》2007,3(3):211-221
There is a general consensus that supports the need for standardized reporting of metadata or information describing large-scale
metabolomics and other functional genomics data sets. Reporting of standard metadata provides a biological and empirical context
for the data, facilitates experimental replication, and enables the re-interrogation and comparison of data by others. Accordingly,
the Metabolomics Standards Initiative is building a general consensus concerning the minimum reporting standards for metabolomics
experiments of which the Chemical Analysis Working Group (CAWG) is a member of this community effort. This article proposes
the minimum reporting standards related to the chemical analysis aspects of metabolomics experiments including: sample preparation,
experimental analysis, quality control, metabolite identification, and data pre-processing. These minimum standards currently
focus mostly upon mass spectrometry and nuclear magnetic resonance spectroscopy due to the popularity of these techniques
in metabolomics. However, additional input concerning other techniques is welcomed and can be provided via the CAWG on-line
discussion forum at or . Further, community input related to this document can also be provided via this electronic forum.
The contents of this paper do not necessarily reflect any position of the Government or the opinion of the Food and Drug Administration
Sponsor: Metabolomics Society http://www.metabolomicssociety.org/
Reference: http://msi-workgroups.sourceforge.net/bio-metadata/reporting/pbc/
http://msi-workgroups.sourceforge.net/chemical-analysis/
Version: Revision: 5.1
Date: 09 January, 2007 相似文献
34.
Anand A Lei Z Sumner LW Mysore KS Arakane Y Bockus WW Muthukrishnan S 《Molecular plant-microbe interactions : MPMI》2004,17(12):1306-1317
A transgenic wheat line constitutively expressing genes encoding a class IV acidic chitinase and an acidic beta-1,3-glucanase, showed significant delay in spread of Fusarium head blight (scab) disease under greenhouse conditions. In an earlier work, we observed a lesion-mimic phenotype in this transgenic line when homozygous for transgene loci. Apoplastic fluid (AF) extracted from the lesion-mimic plants had pathogenesis-related (PR) proteins belonging to families of beta-1,3-glucanases, chitinases, and thaumatin-like proteins (TLPs). AF had growth inhibitory activity against certain fungal pathogens, including Fusarium graminearum and Gaeumannomyces graminis var. tritici. Through a two-step ion-exchange chromatography protocol, we recovered many PR proteins and a few uncharacterized proteins. Three individual protein bands corresponding to a TLP (molecular mass, 16 kDa) and two beta-1,3-glucanases (molecular mass, 32 kDa each) were purified and identified by tandem mass spectrometry. We measured the in vitro antifungal activity of the three purified enzymes and a barley class II chitinase (purified earlier in our laboratory) in microtiter plate assays with macroconidia or conidiophores of F. graminearum and Pyrenophora tritici-repentis. Mixtures of proteins revealed synergistic or additive inhibitory activity against F. graminearum and P. tritici-repentis hyphae. The concentrations of PR proteins at which these effects were observed are likely to be those reached in AF of cells exhibiting a hypersensitive response. Our results suggest that apoplastic PR proteins are antifungal and their antimicrobial potency is dependent on concentrations and combinations that are effectively reached in plants following microbial attack. 相似文献
35.
36.
Sumner S Nash DR Boomsma JJ 《Proceedings. Biological sciences / The Royal Society》2003,270(1521):1315-1322
Social parasites exploit the socially managed resources of their host's society. Inquiline social parasites are dependent on their host throughout their life cycle, and so many of the traits inherited from their free-living ancestor are removed by natural selection. One trait that is commonly lost is the worker caste, the functions of which are adequately fulfilled by host workers. The few inquiline parasites that have retained a worker caste are thought to be at a transitional stage in the evolution of social parasitism, and their worker castes are considered vestigial and non-adaptive. However, this idea has not been tested. Furthermore, whether inquiline workers have an adaptive role outside the usual worker repertoire of foraging, brood care and colony maintenance has not been examined. In this paper, we present data that suggest that workers of the inquiline ant Acromyrmex insinuator play a vital role in ensuring the parasite's fitness. We show that the presence of these parasite workers has a positive effect on the production of parasite sexuals and a negative effect on the production of host sexuals. This suggests that inquiline workers play a vital role in suppressing host queen reproduction, thus promoting the rearing of parasite sexuals. To our knowledge, these are the first experiments on inquiline workers and the first to provide evidence that inquiline workers have an adaptive role. 相似文献
37.
Phenotypic heterogeneity describes non-genetic variation that exists between individual cells within isogenic populations. The basis for such heterogeneity is not well understood, but it is evident in a wide range of cellular functions and phenotypes and may be fundamental to the fitness of microorganisms. Here we use a suite of novel assays applied to yeast, to provide an explanation for the classic example of heterogeneous resistance to stress (copper). Cell cycle stage and replicative cell age, but not mitochondrial content, were found to be principal parameters underpinning differential Cu resistance: cell cycle-synchronized cells had relatively uniform Cu resistances, and replicative cell-age profiles differed markedly in sorted Cu-resistant and Cu-sensitive subpopulations. From a range of potential Cu-sensitive mutants, cup1Delta cells lacking Cu-metallothionein, and particularly sod1Delta cells lacking Cu, Zn-superoxide dismutase, exhibited diminished heterogeneity. Furthermore, age-dependent Cu resistance was largely abolished in cup1Delta and sod1Delta cells, whereas cell cycle-dependent Cu resistance was suppressed in sod1Delta cells. Sod1p activity oscillated approximately fivefold during the cell cycle, with peak activity coinciding with peak Cu-resistance. Thus, phenotypic heterogeneity in copper resistance is not stochastic but is driven by the progression of individual cells through the cell cycle and ageing, and is primarily dependent on only Sod1p, out of several gene products that can influence the averaged phenotype. We propose that such heterogeneity provides an important insurance mechanism for organisms; creating subpopulations that are pre-equipped for varied activities as needs may arise (e.g. when faced with stress), but without the permanent metabolic costs of constitutive expression. 相似文献
38.
Tamez-Guerra P McGuire MR Behle RW Hamm JJ Sumner HR Shasha BS 《Journal of economic entomology》2000,93(2):210-218
Nuclear polyhedrosis viruses such as the one isolated from the celery looper, Anagrapha falcifera (Kirby) (AfMNPV), have the potential to be successful bioinsecticides if improved formulations can prevent rapid loss of insecticidal activity from environmental conditions such as sunlight and rainfall. We tested 16 spray-dried formulations of AfMNPV to determine the effect of different ingredients (e.g., lignin, corn flour, and so on) on insecticidal activity after simulated rain and simulated sunlight (at Peoria, IL) and natural sunlight exposures (at Tifton, GA). The most effective formulation contained pregelatinized corn flour and potassium lignate, which retained more than half of its original activity after 5 cm of simulated rain, and almost full activity after 8 h of simulated sunlight. In Georgia, formulations made with and without lignin were compared for persistence of insecticidal activity when exposed to natural sunlight. In addition, the effect of fluorescent brighteners as formulation components and spray tank additives was tested. Results showed that the formulations with lignin had more insecticidal activity remaining after sunlight exposure than formulations without lignin. The inclusion of brighteners in the formulation did not improve initial activity or virus persistence. However, a 1% tank mix significantly enhanced activity and improved persistence. Scanning electron micrographs revealed discreet particles, and transmission electron micrographs showed virus embedded within microgranules. Results demonstrated that formulations made with natural ingredients could improve persistence of virus-based biopesticides. 相似文献
39.
Viral Co-Infections in Pediatric Patients Hospitalized with Lower Tract Acute Respiratory Infections
Miriam Cebey-López Jethro Herberg Jacobo Pardo-Seco Alberto Gómez-Carballa Nazareth Martinón-Torres Antonio Salas José María Martinón-Sánchez Stuart Gormley Edward Sumner Colin Fink Federico Martinón-Torres GENDRES network 《PloS one》2015,10(9)
Background
Molecular techniques can often reveal a broader range of pathogens in respiratory infections. We aim to investigate the prevalence and age pattern of viral co-infection in children hospitalized with lower tract acute respiratory infection (LT-ARI), using molecular techniques.Methods
A nested polymerase chain reaction approach was used to detect Influenza (A, B), metapneumovirus, respiratory syncytial virus (RSV), parainfluenza (1–4), rhinovirus, adenovirus (A—F), bocavirus and coronaviruses (NL63, 229E, OC43) in respiratory samples of children with acute respiratory infection prospectively admitted to any of the GENDRES network hospitals between 2011–2013. The results were corroborated in an independent cohort collected in the UK.Results
A total of 204 and 97 nasopharyngeal samples were collected in the GENDRES and UK cohorts, respectively. In both cohorts, RSV was the most frequent pathogen (52.9% and 36.1% of the cohorts, respectively). Co-infection with multiple viruses was found in 92 samples (45.1%) and 29 samples (29.9%), respectively; this was most frequent in the 12–24 months age group. The most frequently observed co-infection patterns were RSV—Rhinovirus (23 patients, 11.3%, GENDRES cohort) and RSV—bocavirus / bocavirus—influenza (5 patients, 5.2%, UK cohort).Conclusion
The presence of more than one virus in pediatric patients admitted to hospital with LT-ARI is very frequent and seems to peak at 12–24 months of age. The clinical significance of these findings is unclear but should warrant further analysis. 相似文献40.
Joanna Sumner Jonathan K. Webb Richard Shine J. Scott Keogh 《Conservation Genetics》2010,11(3):747-758
The Broad-headed snake Hoplocephalus bungaroides is one of Australia’s most endangered vertebrates. Extant populations of H. bungaroides are restricted to several geographically isolated reserves to the north, west, and south of Sydney. We analysed mitochondrial
DNA from 184 specimens drawn from across the geographic range of the Broad-headed snake. Phylogenetic analysis demonstrated
that H. bungaroides comprises two divergent mitochondrial lineages with a “northern” clade comprising populations west and north of Sydney and
a “southern” clade comprising animals in Morton National Park. The two clades differ by an uncorrected genetic distance of
1.7%, which implies a divergence dating to approximately 755,000–850,000 years ago. We complemented our molecular data set
with a detailed analysis of morphological variation both between and within the genetic clades. The two H. bungaroides genetic clades are morphologically indistinguishable and show little sexual dimorphism. Our results demonstrate that the
populations north and south of this biogeographic split function as two distinct populations with no recent gene flow. There
is no reason for separate taxonomic recognition of these two clades, but they do represent distinct evolutionarily significant
units (ESUs) that require separate conservation management. In addition, within the northern ESU, populations from Royal National
Park, Blue Mountains National Park, Wollemi National Park, and the Sydney Water Catchment supply areas should be considered
as separate management units to conserve both evolutionary and ecological processes. 相似文献