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311.
Louis Trevisan Lawrence W. Fitzgerald Nils Brose Gregory P. Gasic Stephen F. Heinemann Ronald S. Duman Eric J. Nestler 《Journal of neurochemistry》1994,62(4):1635-1638
We examined the effects of chronic ethanol exposure on the levels of N -methyl-D-aspartate receptor subunit 1 (NMDAR1) protein, an essential component of N -methyl-D-aspar- tate glutamate receptors, in rat brain. By immunoblotting procedures using a specific antibody for the NMDAR1 subunit, we found that ethanol dramatically up-regulated (by 65%) NMDAR1 immunoreactivity in the hippocampus but not in the nucleus accumbens, cerebral cortex, or striatum. In contrast, ethanol did not alter the levels of glutamate receptor subunit (GLUR) 1 or GLUR2 protein, subunits that make up the α-amino-3-hydroxy-5-methy4-isoxazole propionic acid glutamate receptor, in the hippocampus. Because ethanol can potentially influence many different neurotransmitter systems, we examined whether chronic treatment with several psychotropic drugs with different pharmacological profiles (cocaine, haloperidol, SCH 23390, imipramine, and morphine) could mimic the effect of ethanol. None of these agents increased hippocampal NMDAR1 subunit immunoreactivity after chronic administration. Increased NMDAR1 subunit levels in the hippocampus after chronic ethanol exposure may represent an important neurochemical substrate for some of the features associated with ethanol dependence and withdrawal. 相似文献
312.
Pascal Bonnarme Serge Moukha Patrick Moreau Eric Record Laurence Lesage Claude Cassagne Marcel Asther 《FEMS microbiology letters》1994,120(1-2):155-161
Abstract Mycelia from the basidiomycete Phanerochaete chrysosporium , producing lignin and manganese peroxidases, were homogenized and fractionated on a sucrose gradient. The main subcellular fungal membrane fractions were successfully separated. Lipid composition analyses of the isolated membranes as well as associated marker enzymes distribution gave evidence to similarities with membranes originating from plants. Lignin and manganese peroxidases were investigated by immunodetection in subcellular fractions. Our results show that lignin and manganese peroxidases are mainly associated with Golgi apparatus vesicles and, to a lesser extent, with endoplasmic reticulum and light density vesicles, but not with plasma membranes. 相似文献
313.
Functional characteristics of dystrophic skeletal muscle: insights from animal models. 总被引:8,自引:0,他引:8
Muscular dystrophies are a clinically and genetically heterogeneous group of disorders that show myofiber degeneration and regeneration. Identification of animal models of muscular dystrophy has been instrumental in research on the pathogenesis, pathophysiology, and treatment of these disorders. We review our understanding of the functional status of dystrophic skeletal muscle from selected animal models with a focus on 1) the mdx mouse model of Duchenne muscular dystrophy, 2) the Bio 14.6 delta-sarcoglycan-deficient hamster model of limb-girdle muscular dystrophy, and 3) transgenic null mutant murine lines of sarcoglycan (alpha, beta, delta, and gamma) deficiencies. Although biochemical data from these models suggest that the dystrophin-sarcoglycan-dystroglycan-laminin network is critical for structural integrity of the myofiber plasma membrane, emerging studies of muscle physiology suggest a more complex picture, with specific functional deficits varying considerably from muscle to muscle and model to model. It is likely that changes in muscle structure and function, downstream of the specific, primary biochemical deficiency, may alter muscle contractile properties. 相似文献
314.
Eric M. Lind Elizabeth Borer Eric Seabloom Peter Adler Jonathan D. Bakker Dana M. Blumenthal Mick Crawley Kendi Davies Jennifer Firn Daniel S. Gruner W. Stanley Harpole Yann Hautier Helmut Hillebrand Johannes Knops Brett Melbourne Brent Mortensen Anita C. Risch Martin Schuetz Carly Stevens Peter D. Wragg 《Ecology letters》2013,16(4):513-521
Plant growth can be limited by resource acquisition and defence against consumers, leading to contrasting trade‐off possibilities. The competition‐defence hypothesis posits a trade‐off between competitive ability and defence against enemies (e.g. herbivores and pathogens). The growth‐defence hypothesis suggests that strong competitors for nutrients are also defended against enemies, at a cost to growth rate. We tested these hypotheses using observations of 706 plant populations of over 500 species before and following identical fertilisation and fencing treatments at 39 grassland sites worldwide. Strong positive covariance in species responses to both treatments provided support for a growth‐defence trade‐off: populations that increased with the removal of nutrient limitation (poor competitors) also increased following removal of consumers. This result held globally across 4 years within plant life‐history groups and within the majority of individual sites. Thus, a growth‐defence trade‐off appears to be the norm, and mechanisms maintaining grassland biodiversity may operate within this constraint. 相似文献
315.
316.
Baptiste Castel Sebastian Fairhead Oliver J. Furzer Amey Redkar Shanshan Wang Volkan Cevik Eric B. Holub Jonathan D. G. Jones 《The Plant journal : for cell and molecular biology》2021,107(5):1490-1502
The oomycete Albugo candida causes white rust of Brassicaceae, including vegetable and oilseed crops, and wild relatives such as Arabidopsis thaliana. Novel White Rust Resistance (WRR) genes from Arabidopsis enable new insights into plant/parasite co-evolution. WRR4A from Arabidopsis accession Columbia (Col-0) provides resistance to many but not all white rust races, and encodes a nucleotide-binding, leucine-rich repeat immune receptor. Col-0 WRR4A resistance is broken by AcEx1, an isolate of A. candida. We identified an allele of WRR4A in Arabidopsis accession Øystese-0 (Oy-0) and other accessions that confers full resistance to AcEx1. WRR4AOy-0 carries a C-terminal extension required for recognition of AcEx1, but reduces recognition of several effectors recognized by the WRR4ACol-0 allele. WRR4AOy-0 confers full resistance to AcEx1 when expressed in the oilseed crop Camelina sativa. 相似文献
317.
Nathan G Walworth Michael D Lee Egor Dolzhenko Fei-Xue Fu Andrew D Smith Eric A Webb David A Hutchins 《Molecular biology and evolution》2021,38(3):927
A major challenge in modern biology is understanding how the effects of short-term biological responses influence long-term evolutionary adaptation, defined as a genetically determined increase in fitness to novel environments. This is particularly important in globally important microbes experiencing rapid global change, due to their influence on food webs, biogeochemical cycles, and climate. Epigenetic modifications like methylation have been demonstrated to influence short-term plastic responses, which ultimately impact long-term adaptive responses to environmental change. However, there remains a paucity of empirical research examining long-term methylation dynamics during environmental adaptation in nonmodel, ecologically important microbes. Here, we show the first empirical evidence in a marine prokaryote for long-term m5C methylome modifications correlated with phenotypic adaptation to CO2, using a 7-year evolution experiment (1,000+ generations) with the biogeochemically important marine cyanobacterium Trichodesmium. We identify m5C methylated sites that rapidly changed in response to high (750 µatm) CO2 exposure and were maintained for at least 4.5 years of CO2 selection. After 7 years of CO2 selection, however, m5C methylation levels that initially responded to high-CO2 returned to ancestral, ambient CO2 levels. Concurrently, high-CO2 adapted growth and N2 fixation rates remained significantly higher than those of ambient CO2 adapted cell lines irrespective of CO2 concentration, a trend consistent with genetic assimilation theory. These data demonstrate the maintenance of CO2-responsive m5C methylation for 4.5 years alongside phenotypic adaptation before returning to ancestral methylation levels. These observations in a globally distributed marine prokaryote provide critical evolutionary insights into biogeochemically important traits under global change. 相似文献
318.
319.
320.
Eric Wilkes 《BMJ (Clinical research ed.)》1980,281(6253):1471