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51.
Effects of the Epichloë fungal endophyte symbiosis with Schedonorus pratensis on host grass invasiveness 下载免费PDF全文
Kruti Shukla Heather A. Hager Kathryn A. Yurkonis Jonathan A. Newman 《Ecology and evolution》2015,5(13):2596-2607
Initial studies of grass–endophyte mutualisms using Schedonorus arundinaceus cultivar Kentucky‐31 infected with the vertically transmitted endophyte Epichloë coenophiala found strong, positive endophyte effects on host‐grass invasion success. However, more recent work using different cultivars of S. arundinaceus has cast doubt on the ubiquity of this effect, at least as it pertains to S. arundinaceus–E. coenophiala. We investigated the generality of previous work on vertically transmitted Epichloë‐associated grass invasiveness by studying a pair of very closely related species: S. pratensis and E. uncinata. Seven cultivars of S. pratensis and two cultivars of S. arundinaceus that were developed with high‐ or low‐endophyte infection rate were broadcast seeded into 2 × 2‐m plots in a tilled, old‐field grassland community in a completely randomized block design. Schedonorus abundance, endophyte infection rate, and co‐occurring vegetation were sampled 3, 4, 5, and 6 years after establishment, and the aboveground invertebrate community was sampled in S. pratensis plots 3 and 4 years after establishment. Endophyte infection did not enable the host grass to achieve high abundance in the plant community. Contrary to expectations, high‐endophyte S. pratensis increased plant richness relative to low‐endophyte cultivars. However, as expected, high‐endophyte S. pratensis marginally decreased invertebrate taxon richness. Endophyte effects on vegetation and invertebrate community composition were inconsistent among cultivars and were weaker than temporal effects. The effect of the grass–Epichloë symbiosis on diversity is not generalizable, but rather specific to species, cultivar, infection, and potentially site. Examining grass–endophyte systems using multiple cultivars and species replicated among sites will be important to determine the range of conditions in which endophyte associations benefit host grass performance and have subsequent effects on co‐occurring biotic communities. 相似文献
52.
Structural Changes of Cell Wall and Lignifying Enzymes Modulations in Bean Roots in Response to Copper Stress 总被引:3,自引:0,他引:3
Houda Bouazizi Hager Jouili Anja Geitmann Ezzeddine El Ferjani 《Biological trace element research》2010,136(2):232-240
Fourteen-day-old bean seedlings were cultured in nutrient solution containing Cu2+ ions at various concentrations (50 and 75 μM of CuSO4) for 3 days. This excess of copper induced a reduction in the water volume absorbed by the plants. Moreover, this reduction
was accompanied by an increase of the amount of copper taken up by the roots. Analysis by native gel electrophoresis of cell
wall peroxidase activities in the roots revealed a stimulation of two anionic isoforms (A2 and A3) under cupric stress conditions. Moreover, the activity of phenylalanine ammonia lyase (EC. 4.3.1.5), which plays an important
role in plant defense, was enhanced. Copper-treated bean roots showed modifications in the cell walls of various tissues.
Label for lignin, callose, and suberin with berberine-aniline blue revealed abnormal cell wall thickenings in the endodermis,
the phloem, and the xylem, especially in plants treated with 75 μM CuSO4. 相似文献
53.
54.
Jacques Décombaz Alexandre Bury Corinne Hager 《Journal of applied physiology》2003,95(5):2180-2; author reply 2182
55.
Formalin fixation has been the standard method for conservation of clinical specimens for decades. However, a major drawback is the high degradation of nucleic acids, which complicates its use in genome-wide analyses. Unbiased identification of biomarkers, however, requires genome-wide studies, precluding the use of the valuable archives of specimens with long-term follow-up data. Therefore, restoration protocols for DNA from formalin-fixed and paraffin-embedded (FFPE) samples have been developed, although they are cost-intensive and time-consuming. An alternative to FFPE and snap-freezing is the PAXgene Tissue System, developed for simultaneous preservation of morphology, proteins, and nucleic acids. In the current study, we compared the performance of DNA from either PAXgene or formalin-fixed tissues to snap-frozen material for genome-wide DNA methylation analysis using the Illumina 450K BeadChip. Quantitative DNA methylation analysis demonstrated that the methylation profile in PAXgene-fixed tissues showed, in comparison with restored FFPE samples, a higher concordance with the profile detected in frozen samples. We demonstrate, for the first time, that DNA from PAXgene conserved tissue performs better compared with restored FFPE DNA in genome-wide DNA methylation analysis. In addition, DNA from PAXgene tissue can be directly used on the array without prior restoration, rendering the analytical process significantly more time- and cost-effective. 相似文献
56.
New Face for Chromatin‐Related Mesenchymal Modulator: n‐CHD9 Localizes to Nucleoli and Interacts With Ribosomal Genes 下载免费PDF全文
57.
58.
Fairfield H Gilbert GJ Barter M Corrigan RR Curtain M Ding Y D'Ascenzo M Gerhardt DJ He C Huang W Richmond T Rowe L Probst FJ Bergstrom DE Murray SA Bult C Richardson J Kile BT Gut I Hager J Sigurdsson S Mauceli E Di Palma F Lindblad-Toh K Cunningham ML Cox TC Justice MJ Spector MS Lowe SW Albert T Donahue LR Jeddeloh J Shendure J Reinholdt LG 《Genome biology》2011,12(9):R86-12
We report the development and optimization of reagents for in-solution, hybridization-based capture of the mouse exome. By validating this approach in a multiple inbred strains and in novel mutant strains, we show that whole exome sequencing is a robust approach for discovery of putative mutations, irrespective of strain background. We found strong candidate mutations for the majority of mutant exomes sequenced, including new models of orofacial clefting, urogenital dysmorphology, kyphosis and autoimmune hepatitis. 相似文献
59.
Lavinia Paternoster David M. Evans Ellen Aagaard Nohr Claus Holst Valerie Gaborieau Paul Brennan Anette Prior Gjesing Niels Grarup Daniel R. Witte Torben J?rgensen Allan Linneberg Torsten Lauritzen Anelli Sandbaek Torben Hansen Oluf Pedersen Katherine S. Elliott John P. Kemp Beate St. Pourcain George McMahon Diana Zelenika J?rg Hager Mark Lathrop Nicholas J. Timpson George Davey Smith Thorkild I. A. S?rensen 《PloS one》2011,6(9)
60.
Differential in vivo binding dynamics of somatic and oocyte-specific linker histones in oocytes and during ES cell nuclear transfer 总被引:2,自引:0,他引:2 下载免费PDF全文
Becker M Becker A Miyara F Han Z Kihara M Brown DT Hager GL Latham K Adashi EY Misteli T 《Molecular biology of the cell》2005,16(8):3887-3895
The embryonic genome is formed by fusion of a maternal and a paternal genome. To accommodate the resulting diploid genome in the fertilized oocyte dramatic global genome reorganizations must occur. The higher order structure of chromatin in vivo is critically dependent on architectural chromatin proteins, with the family of linker histone proteins among the most critical structural determinants. Although somatic cells contain numerous linker histone variants, only one, H1FOO, is present in mouse oocytes. Upon fertilization H1FOO rapidly populates the introduced paternal genome and replaces sperm-specific histone-like proteins. The same dynamic replacement occurs upon introduction of a nucleus during somatic cell nuclear transfer. To understand the molecular basis of this dynamic histone replacement process, we compared the localization and binding dynamics of somatic H1 and oocyte-specific H1FOO and identified the molecular determinants of binding to either oocyte or somatic chromatin in living cells. We find that although both histones associate readily with chromatin in nuclei of somatic cells, only H1FOO is capable of correct chromatin association in the germinal vesicle stage oocyte nuclei. This specificity is generated by the N-terminal and globular domains of H1FOO. Measurement of in vivo binding properties of the H1 variants suggest that H1FOO binds chromatin more tightly than somatic linker histones. We provide evidence that both the binding properties of linker histones as well as additional, active processes contribute to the replacement of somatic histones with H1FOO during nuclear transfer. These results provide the first mechanistic insights into the crucial step of linker histone replacement as it occurs during fertilization and somatic cell nuclear transfer. 相似文献