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71.
Marc W. Schmid Terhi Hahl Sofia J. van Moorsel Cameron Wagg Gerlinde B. De Deyn Bernhard Schmid 《Molecular ecology》2019,28(4):863-878
Soil microbes are known to be key drivers of several essential ecosystem processes such as nutrient cycling, plant productivity and the maintenance of plant species diversity. However, how plant species diversity and identity affect soil microbial diversity and community composition in the rhizosphere is largely unknown. We tested whether, over the course of 11 years, distinct soil bacterial communities developed under plant monocultures and mixtures, and if over this time frame plants with a monoculture or mixture history changed in the bacterial communities they associated with. For eight species, we grew offspring of plants that had been grown for 11 years in the same field monocultures or mixtures (plant history in monoculture vs. mixture) in pots inoculated with microbes extracted from the field monoculture and mixture soils attached to the roots of the host plants (soil legacy). After 5 months of growth in the glasshouse, we collected rhizosphere soil from each plant and used 16S rRNA gene sequencing to determine the community composition and diversity of the bacterial communities. Bacterial community structure in the plant rhizosphere was primarily determined by soil legacy and by plant species identity, but not by plant history. In seven of the eight plant species the number of individual operational taxonomic units with increased abundance was larger when inoculated with microbes from mixture soil. We conclude that plant species richness can affect below‐ground community composition and diversity, feeding back to the assemblage of rhizosphere bacterial communities in newly establishing plants via the legacy in soil. 相似文献
72.
Hildén K Hakala TK Maijala P Lundell TK Hatakka A 《Applied microbiology and biotechnology》2007,77(2):301-309
The white-rot basidiomycete Physisporinus rivulosus strain T241i is highly selective for degradation of softwood lignin, which makes this fungus suitable for biopulping. In
order to promote laccase production, P. rivulosus was cultivated in nutrient-nitrogen sufficient liquid media containing either charcoal or spruce sawdust as supplements.
Two laccases with distinct pI values, Lac-3.5 and Lac-4.8, were purified from peptone-spruce sawdust-charcoal cultures of P. rivulosus. Both laccases showed thermal stability at up to 60°C. Lac-4.8 was thermally activated at 50°C. Surprisingly, both laccases
displayed atypically low pH optima (pH 3.0–3.5) in oxidation of the commonly used laccase substrates syringaldazine (4-hydroxy-3,5-dimethoxybenzaldehyde
azine), 2,6-dimethoxyphenol and guaiacol (2-methoxyphenol). Steady-state kinetic measurements pointed to unusually low affinity
to guaiacol at low pH, whereas the kinetic constants for the methoxyphenols and ABTS were within the ranges reported for other
fungal laccases. The combination of thermotolerance with low pH optima for methoxylated phenol substrates suggests that the
two P. rivulosus T241i laccases possess potential for use in biotechnological applications. 相似文献
73.
Terhi Iso-Touru Juha Kantanen Meng-Hua Li Zygmunt Gizejewski Johanna Vilkki 《BMC evolutionary biology》2009,9(1):172-11
Background
Prolactin receptor (PRLR) and growth hormone receptor (GHR) belong to the large superfamily of class 1 cytokine receptors. Both of them have been identified as candidate genes affecting key quantitative traits, like growth and reproduction in livestock. We have previously studied the molecular anatomy of the cytoplasmic domain of GHR in different cattle breeds and artiodactyl species. In this study we have analysed the corresponding cytoplasmic signalling region of PRLR. 相似文献74.
Population structure of a threatened plant, Pulsatilla patens, in boreal forests: modelling relationships to overgrowth and site closure 总被引:2,自引:0,他引:2
Mika Kalliovirta Terhi Ryttäri Risto K. Heikkinen 《Biodiversity and Conservation》2006,15(9):3095-3108
Pulsatilla patens (L.) Mill. (Ranunculaceae) is a threatened plant which in Fennoscandia favours south-facing, warm slopes of pine-dominated
esker forests. The cessation of cattle grazing, modern forestry practices, and especially efficient fire prevention have resulted
in closure of undergrowth vegetation in these forests. Using generalized linear models (GLM), we studied the relationships
between habitat factors (covers of field and ground layer and amount of litter) and the population structure of P. patens in 48 populations in Finland in order to identify favourable conditions for regeneration. The largest populations occurred
at sites with intermediate values of both ground and field layer. The number of juvenile plants was also highest at intermediate
values of ground layer. Dense moss layer and abundant litter had a negative effect on the flowering of P. patens. In conclusion, creation and maintenance of habitat heterogeneity to prevent the closure of undergrowth vegetation is of
paramount importance for the successful reproduction of P. patens. 相似文献
75.
Rilla K Pasonen-Seppänen S Kärnä R Karjalainen HM Törrönen K Koistinen V Tammi MI Tammi RH Teräväinen T Manninen A 《Histochemistry and cell biology》2012,137(2):153-164
The amount of hyaluronan (HA) is low in simple epithelia under normal conditions, but during tumorigenesis, trauma or inflammation
HA is increased on the epithelial cells and surrounding stroma. Excessive HA in epithelia is suggested to interfere with cell–cell
adhesions, resulting in disruption of the epithelial barrier function. In addition, stimulated HA synthesis has been correlated
with epithelial-to-mesenchymal transition and invasion of cancer cells. However, the effects of HA overload on normal epithelial
morphogenesis have not been characterized in detail. Madin-Darby canine kidney (MDCK) cells form polarized epithelial cysts,
when grown in a 3-dimensional (3D) matrix. These cells were used to investigate whether stimulated HA synthesis, induced by
stable overexpression of GFP-HAS3, influences cell polarization and epithelial morphogenesis. GFP-HAS3 expression in polarized
MDCK cells resulted in active HA secretion at apical and basolateral membrane domains. HA-deposits interfered with the formation
of cell–cell junctions, resulting in impaired barrier function. In 3D cyst cultures, HA accumulated into apical lumina and
was also secreted from the basal side. The HAS3-expressing cysts failed to form a single lumen and instead displayed multiple
small lumina. This phenotype was correlated with aberrant mitotic spindle orientation in dividing cells. The results of this
study indicate that excess pericellular HA disturbs the normal cell–cell and cell–ECM interactions in simple epithelia, leading
to aberrant epithelial morphogenesis. The morphological abnormalities observed in 3D epithelial cultures upon stimulated HAS3
expression may be related to premalignant changes, including intraluminal invasion and deregulated epithelialization, probably
mediated by the mitotic spindle orientation defects. 相似文献
76.
Background
Formation of apical compartments underlies the morphogenesis of most epithelial organs during development. The extracellular matrix (ECM), particularly the basement membrane (BM), plays an important role in orienting the apico-basal polarity and thereby the positioning of apical lumens. Integrins have been recognized as essential mediators of matrix-derived polarity signals. The importance of β1-integrins in epithelial polarization is well established but the significance of the accompanying α-subunits have not been analyzed in detail.Principal Findings
Here we demonstrate that two distinct integrin-dependent pathways regulate formation of apical lumens to ensure robust apical membrane biogenesis under different microenvironmental conditions; 1) α2β1- and α6β4-integrins were required to establish a basal cue that depends on Rac1-activity and guides apico-basal cell polarization. 2) α3β1-integrins were implicated in positioning of mitotic spindles in cysts, a process that is essential for Cdc42-driven epithelial hollowing.Significance
Identification of the separate processes driven by particular integrin receptors clarifies the functional hierarchies between the different integrins co-expressed in epithelial cells and provides valuable insight into the complexity of cell-ECM interactions thereby guiding future studies addressing the molecular basis of epithelial morphogenesis during development and disease. 相似文献77.
Silvana Romio Daniel Weibel Jeanne P. Dieleman Henning K. Olberg Corinne S. de Vries Cormac Sammon Nick Andrews Henrik Svanstr?m Ditte M?lgaard-Nielsen Anders Hviid Maryse Lapeyre-Mestre Agnès Sommet Christel Saussier Anne Castot Harald Heijbel Lisen Arnheim-Dahlstr?m Par Sparen Mees Mosseveld Martijn Schuemie Nicoline van der Maas Bart C. Jacobs Tuija Leino Terhi Kilpi Jann Storsaeter Kari Johansen Piotr Kramarz Jan Bonhoeffer Miriam C. J. M. Sturkenboom 《PloS one》2014,9(1)
Background
The risk of Guillain-Barré syndrome (GBS) following the United States'' 1976 swine flu vaccination campaign in the USA led to enhanced active surveillance during the pandemic influenza (A(H1N1)pdm09) immunization campaign. This study aimed to estimate the risk of GBS following influenza A(H1N1)pdm09 vaccination.Methods
A self-controlled case series (SCCS) analysis was performed in Denmark, Finland, France, Netherlands, Norway, Sweden, and the United Kingdom. Information was collected according to a common protocol and standardised procedures. Cases classified at levels 1–4a of the Brighton Collaboration case definition were included. The risk window was 42 days starting the day after vaccination. Conditional Poisson regression and pooled random effects models estimated adjusted relative incidences (RI). Pseudo likelihood and vaccinated-only methods addressed the potential contraindication for vaccination following GBS.Results
Three hundred and three (303) GBS and Miller Fisher syndrome cases were included. Ninety-nine (99) were exposed to A(H1N1)pdm09 vaccination, which was most frequently adjuvanted (Pandemrix and Focetria). The unadjusted pooled RI for A(H1N1)pdm09 vaccination and GBS was 3.5 (95% Confidence Interval (CI): 2.2–5.5), based on all countries. This lowered to 2.0 (95% CI: 1.2–3.1) after adjustment for calendartime and to 1.9 (95% CI: 1.1–3.2) when we accounted for contra-indications. In a subset (Netherlands, Norway, and United Kingdom) we further adjusted for other confounders and there the RI decreased from 1.7 (adjusted for calendar month) to 1.4 (95% CI: 0.7–2.8), which is the main finding.Conclusion
This study illustrates the potential of conducting European collaborative vaccine safety studies. The main, fully adjusted analysis, showed that the RI of GBS was not significantly elevated after influenza A(H1N1)pdm09 vaccination (RI = 1.4 (95% CI: 0.7–2.8). Based on the upper limits of the pooled estimate we can rule out with 95% certainty that the number of excess GBS cases after influenza A(H1N1)pdm09 vaccination would be more than 3 per million vaccinated. 相似文献78.
M. Nadeem Asghar Jonas S. G. Silvander Terhi O. Helenius Iris A. K. L?hdeniemi Catharina Alam Lina E. Fortelius Rickard O. Holmsten Diana M. Toivola 《PloS one》2015,10(5)
Keratins (K) are important for epithelial stress protection as evidenced by keratin mutations predisposing to human liver diseases and possibly inflammatory bowel diseases. A role for K8 in the colon is supported by the ulcerative colitis-phenotype with epithelial hyperproliferation and abnormal ion transport in K8-knockout (K8−/−) mice. The heterozygote knockout (K8+/−) colon appears normal but displays a partial ion transport-defect. Characterizing the colonic phenotype we show that K8+/− colon expresses ~50% less keratins compared to K8 wild type (K8+/+) but de novo K7 expression is observed in the top-most cells of the K8+/− and K8−/− crypts. The K8+/− colonic crypts are significantly longer due to increased epithelial hyperproliferation, but display no defects in apoptosis or inflammation in contrast to K8−/−. When exposed to colitis using the dextran sulphate sodium-model, K8+/− mice showed higher disease sensitivity and delayed recovery compared to K8+/+ littermates. Therefore, the K8+/− mild colonic phenotype correlates with decreased keratin levels and increased sensitivity to experimental colitis, suggesting that a sufficient amount of keratin is needed for efficient stress protection in the colonic epithelia. 相似文献
79.
Marianna Niemi Auli Bl?uer Terhi Iso-Touru Janne Harjula Veronica Nystr?m Edmark Eve Rannam?e Lembi L?ugas Antti Sajantila Kerstin Lidén Jussi-Pekka Taavitsainen 《PloS one》2015,10(5)
BackgroundAncient DNA analysis offers a way to detect changes in populations over time. To date, most studies of ancient cattle have focused on their domestication in prehistory, while only a limited number of studies have analysed later periods. Conversely, the genetic structure of modern cattle populations is well known given the undertaking of several molecular and population genetic studies.ResultsBones and teeth from ancient cattle populations from the North-East Baltic Sea region dated to the Prehistoric (Late Bronze and Iron Age, 5 samples), Medieval (14), and Post-Medieval (26) periods were investigated by sequencing 667 base pairs (bp) from the mitochondrial DNA (mtDNA) and 155 bp of intron 19 in the Y-chromosomal UTY gene. Comparison of maternal (mtDNA haplotypes) genetic diversity in ancient cattle (45 samples) with modern cattle populations in Europe and Asia (2094 samples) revealed 30 ancient mtDNA haplotypes, 24 of which were shared with modern breeds, while 6 were unique to the ancient samples. Of seven Y-chromosomal sequences determined from ancient samples, six were Y2 and one Y1 haplotype. Combined data including Swedish samples from the same periods (64 samples) was compared with the occurrence of Y-chromosomal haplotypes in modern cattle (1614 samples).ConclusionsThe diversity of haplogroups was highest in the Prehistoric samples, where many haplotypes were unique. The Medieval and Post-Medieval samples also show a high diversity with new haplotypes. Some of these haplotypes have become frequent in modern breeds in the Nordic Countries and North-Western Russia while other haplotypes have remained in only a few local breeds or seem to have been lost. A temporal shift in Y-chromosomal haplotypes from Y2 to Y1 was detected that corresponds with the appearance of new mtDNA haplotypes in the Medieval and Post-Medieval period. This suggests a replacement of the Prehistoric mtDNA and Y chromosomal haplotypes by new types of cattle. 相似文献
80.
Iso-Touru Terhi Huitu Otso Tapio Miika Kučinskienė Jūratė Ulevičius Alius Bukelskis Egidijus Tirronen Konstantin Fyodorov Fyodor Panchenko Danila Saarma Urmas Valdmann Harri Kauhala Kaarina 《Acta theriologica》2020,65(2):331-338
Mammal Research - Reduction of genetic diversity can lead to reduced fitness of species, such as the loss of adaptability to changing environments. The native Eurasian beaver (Castor fiber) was... 相似文献