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91.
Pedro Almeida Raquel Barbosa Polona Zalar Yumi Imanishi Kiminori Shimizu Benedetta Turchetti Jean‐Luc Legras Marta Serra Sylvie Dequin Arnaud Couloux Julie Guy Douda Bensasson Paula Gonçalves José Paulo Sampaio 《Molecular ecology》2015,24(21):5412-5427
The domestication of the wine yeast Saccharomyces cerevisiae is thought to be contemporary with the development and expansion of viticulture along the Mediterranean basin. Until now, the unavailability of wild lineages prevented the identification of the closest wild relatives of wine yeasts. Here, we enlarge the collection of natural lineages and employ whole‐genome data of oak‐associated wild isolates to study a balanced number of anthropic and natural S. cerevisiae strains. We identified industrial variants and new geographically delimited populations, including a novel Mediterranean oak population. This population is the closest relative of the wine lineage as shown by a weak population structure and further supported by genomewide population analyses. A coalescent model considering partial isolation with asymmetrical migration, mostly from the wild group into the Wine group, and population growth, was found to be best supported by the data. Importantly, divergence time estimates between the two populations agree with historical evidence for winemaking. We show that three horizontally transmitted regions, previously described to contain genes relevant to wine fermentation, are present in the Wine group but not in the Mediterranean oak group. This represents a major discontinuity between the two populations and is likely to denote a domestication fingerprint in wine yeasts. Taken together, these results indicate that Mediterranean oaks harbour the wild genetic stock of domesticated wine yeasts. 相似文献
92.
Maupin-Furlow J 《Nature reviews. Microbiology》2012,10(2):100-111
Like other energy-dependent proteases, proteasomes, which are found across the three domains of life, are self-compartmentalized and important in the early steps of proteolysis. Proteasomes degrade improperly synthesized, damaged or misfolded proteins and hydrolyse regulatory proteins that must be specifically removed or cleaved for cell signalling. In eukaryotes, proteins are typically targeted for proteasome-mediated destruction through polyubiquitylation, although ubiquitin-independent pathways also exist. Interestingly, actinobacteria and archaea also covalently attach small proteins (prokaryotic ubiquitin-like protein (Pup) and small archaeal modifier proteins (Samps), respectively) to certain proteins, and this may serve to target the modified proteins for degradation by proteasomes. 相似文献
93.
Th‐17 response and antimicrobial peptide expression are uniformly expressed in gastric mucosa of Helicobacter pylori‐infected patients independently of their clinical outcomes 下载免费PDF全文
94.
95.
Julie M. Grossman Brendan E. O’Neill Siu Mui Tsai Biqing Liang Eduardo Neves Johannes Lehmann Janice E. Thies 《Microbial ecology》2010,60(1):192-205
We compared the microbial community composition in soils from the Brazilian Amazon with two contrasting histories; anthrosols
and their adjacent non-anthrosol soils of the same mineralogy. The anthrosols, also known as the Amazonian Dark Earths or
terra preta, were managed by the indigenous pre-Colombian Indians between 500 and 8,700 years before present and are characterized
by unusually high cation exchange capacity, phosphorus (P), and calcium (Ca) contents, and soil carbon pools that contain
a high proportion of incompletely combusted biomass as biochar or black carbon (BC). We sampled paired anthrosol and unmodified
soils from four locations in the Manaus, Brazil, region that differed in their current land use and soil type. Community DNA
was extracted from sampled soils and characterized by use of denaturing gradient gel electrophoresis (DGGE) and terminal restriction
fragment length polymorphism. DNA bands of interest from Bacteria and Archaea DGGE gels were cloned and sequenced. In cluster
analyses of the DNA fingerprints, microbial communities from the anthrosols grouped together regardless of current land use
or soil type and were distinct from those in their respective, paired adjacent soils. For the Archaea, the anthrosol communities
diverged from the adjacent soils by over 90%. A greater overall richness was observed for Bacteria sequences as compared with
those of the Archaea. Most of the sequences obtained were novel and matched those in databases at less than 98% similarity.
Several sequences obtained only from the anthrosols grouped at 93% similarity with the Verrucomicrobia, a genus commonly found in rice paddies in the tropics. Sequences closely related to Proteobacteria and Cyanobacteria sp. were recovered only from adjacent soil samples. Sequences related to Pseudomonas, Acidobacteria, and Flexibacter sp. were recovered from both anthrosols and adjacent soils. The strong similarities among the microbial communities present
in the anthrosols for both the Bacteria and Archaea suggests that the microbial community composition in these soils is controlled
more strongly by their historical soil management than by soil type or current land use. The anthrosols had consistently higher
concentrations of incompletely combusted organic black carbon material (BC), higher soil pH, and higher concentrations of
P and Ca compared to their respective adjacent soils. Such characteristics may help to explain the longevity and distinctiveness
of the anthrosols in the Amazonian landscape and guide us in recreating soils with sustained high fertility in otherwise nutrient-poor
soils in modern times. 相似文献
96.
Milland J Yuriev E Xing PX McKenzie IF Ramsland PA Sandrin MS 《Immunology and cell biology》2007,85(8):623-632
Carbohydrates are involved in many immunological responses including the rejection of incompatible blood, tissues and organs. Carbohydrate antigens with Galalpha(1,3)Gal epitopes are recognized by natural antibodies in humans and pose a major barrier for pig-to-human xenotransplantation. Genetically modified pigs have been established that have no functional alpha1,3-galactosyltransferase (alpha1,3GT), which transfers alphaGal to N-acetyllactosamine (LacNAc) type oligosaccharides. However, a low level of Galalpha(1,3)Gal is still expressed in alpha1,3GT knockout animals in the form of a lipid, isoglobotrihexosylceramide (iGb3), which is produced by iGb3 synthase on lactose (Lac) type core structures. Here, we define the reactivity of a series of monoclonal antibodies (mAb) generated in alpha1,3GT-/- mice immunized with rabbit red blood cells (RbRBC), as a rich source of lipid-linked antigens. Interestingly, one mAb (15.101) binds weakly to synthetic and cell surface-expressed Galalpha(1,3)Gal on LacNAc, but strongly to versions of the antigen on Lac cores, including iGb3. Three-dimensional models suggest that the terminal alpha-linked Gal binds tightly into the antibody-binding cavity. Furthermore, antibody interactions were predicted with the second and third monosaccharide units. Collectively, our findings suggest that although the terminal carbohydrate residues confer most of the binding affinity, the fine specificity is determined by subsequent residues in the oligosaccharide. 相似文献
97.
Elizabeth H. M. Tyler Paul J. Somerfield Edward Vanden Berghe Julie Bremner Emma Jackson Olivia Langmead Maria Lourdes D. Palomares Thomas J. Webb 《Global Ecology and Biogeography》2012,21(9):922-934
Aim Ecologists seeking to describe patterns at ever larger scales require compilations of data on the global abundance and distribution of species. Comparable compilations of biological data are needed to elucidate the mechanisms behind these patterns, but have received far less attention. We assess the availability of biological data across an entire assemblage: the well‐documented demersal marine fauna of the United Kingdom. We also test whether data availability for a species depends on its taxonomic group, maximum body size, the number of times it has been recorded in a global biogeographic database, or its commercial and conservation importance. Location Seas of the United Kingdom. Methods We defined a demersal marine fauna of 973 species from 15 phyla and 40 classes using five extensive surveys around the British Isles. We then quantified the availability of data on eight key biological traits (termed biological knowledge) for each species from online databases. Relationships between biological knowledge and our predictors were tested with generalized linear models. Results Full data on eight fundamental biological traits exist for only 9% (n= 88) of the UK demersal marine fauna, and 20% of species completely lack data. Clear trends in our knowledge exist: fish (median biological knowledge score = six traits) are much better known than invertebrates (one trait). Biological knowledge increases with biogeographic knowledge and (to a lesser extent) with body size, and is greater in species that are commercially exploited or of conservation concern. Main conclusions Our analysis reveals deep ignorance of the basic biology of a well‐studied fauna, highlighting the need for far greater efforts to compile biological trait data. Clear biases in our knowledge, relating to how well sampled or ‘important’ species are suggests that caution is required in extrapolating small subsets of biologically well‐known species to ecosystem‐level studies. 相似文献
98.
Mouaadh Abdelkarim Sandrine Caron Christian Duhem Janne Prawitt Julie Dumont Anthony Lucas Emmanuel Bouchaert Olivier Briand John Brozek Folkert Kuipers Catherine Fievet Bertrand Cariou Bart Staels 《The Journal of biological chemistry》2010,285(47):36759-36767
The bile acid receptor farnesoid X receptor (FXR) is expressed in adipose tissue, but its function remains poorly defined. Peroxisome proliferator-activated receptor-γ (PPARγ) is a master regulator of adipocyte differentiation and function. The aim of this study was to analyze the role of FXR in adipocyte function and to assess whether it modulates PPARγ action. Therefore, we tested the responsiveness of FXR-deficient mice (FXR−/−) and cells to the PPARγ activator rosiglitazone. Our results show that genetically obese FXR−/−/ob/ob mice displayed a resistance to rosiglitazone treatment. In vitro, rosiglitazone treatment did not induce normal adipocyte differentiation and lipid droplet formation in FXR−/− mouse embryonic fibroblasts (MEFs) and preadipocytes. Moreover, FXR−/− MEFs displayed both an increased lipolysis and a decreased de novo lipogenesis, resulting in reduced intracellular triglyceride content, even upon PPARγ activation. Retroviral-mediated FXR re-expression in FXR−/− MEFs restored the induction of adipogenic marker genes during rosiglitazone-forced adipocyte differentiation. The expression of Wnt/β-catenin pathway and target genes was increased in FXR−/− adipose tissue and MEFs. Moreover, the expression of several endogenous inhibitors of this pathway was decreased early during the adipocyte differentiation of FXR−/− MEFs. These findings demonstrate that FXR regulates adipocyte differentiation and function by regulating two counteracting pathways of adipocyte differentiation, the PPARγ and Wnt/β-catenin pathways. 相似文献
99.
ACCLIMATION TO SPECTRAL IRRADIANCE IN ALGAE 总被引:3,自引:0,他引:3
100.
Julie C. Williamson Ed C. Rowe Paul W. Hill Mark A. Nason David L. Jones John R. Healey 《Restoration Ecology》2011,19(2):194-204
Hard rock quarries are commonly located close to national parks and special areas of conservation and are generally regarded as visually intrusive. Consequently, restoration strategies that effectively accelerate natural plant regeneration processes are required. Slate waste tips present extreme conditions for plant establishment with multiple potential limiting factors (e.g., lack of organic matter, nutrients, and poor water retention). In this study, we investigated ecological strategies to accelerate natural regeneration at the largest slate quarry in Europe. A field experiment was conducted to assess ecosystem restoration using a contrasting set of native woody species. Treatments included amendments of waste tips with: polyacrylamide gel to increase water‐holding capacity; mineral fertilizer to increase nutrient supply; and two treatments that increased both (organic waste or boulder clay addition). Ecosystem recovery was evaluated through above‐ and below‐ground productivity (plant and microbial, respectively) and soil analyses. Neither increasing nutrient supply (with mineral fertilizer) nor water‐holding capacity (with polyacrylamide gel) was sufficient, alone, to improve plant establishment. However, both boulder clay and organic waste amendment significantly enhanced plant growth. There was a marked positive interaction in the effects on tree growth of the amendment with organic waste and boulder clay. Large interactions occurred between tree species and substrate amendments. The growth of N2‐fixing species was strongly favored over non‐fixers where there was no addition of material increasing soil nitrogen supply, whereas the growth advantage of pioneer species over non‐pioneers was greatest with fertilizer, organic waste, or clay additions. Organic waste addition had the greatest positive impact on soil processes. 相似文献