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181.
Nishanta Rajakaruna 《The Botanical review》2018,84(1):39-78
Plants adapted to special soil types are ideal for investigating evolutionary processes, including maintenance of intraspecific variation, adaptation, reproductive isolation, ecotypic differentiation, and the tempo and mode of speciation. Common garden and reciprocal transplant approaches show that both local adaptation and phenotypic plasticity contribute to edaphic (soil-related) specialization. Edaphic specialists evolve rapidly and repeatedly in some lineages, offering opportunities to investigate parallel evolution, a process less commonly documented in plants than in animals. Adaptations to soil features are often under the control of major genes and they frequently have direct or indirect effects on genes that contribute to reproductive isolation. Both reduced competitiveness and greater susceptibility to herbivory have been documented among some edaphic specialists when grown in ‘normal’ soils, suggesting that a high physiological cost of tolerance may result in strong divergent selection across soil boundaries. Interactions with microbes, herbivores, and pollinators influence soil specialization either by directly enhancing tolerance to extremes in soil conditions or by reducing gene flow between divergent populations. Climate change may further restrict the distribution of edaphic specialists due to increased competition from other taxa or, expand their ranges, if preadaptations to drought or other abiotic stressors render them more competitive under a novel climate. 相似文献
182.
Elke EM Brouwers Alwin DR Huitema Jos H Beijnen Jan HM Schellens 《BMC clinical pharmacology》2008,8(1):7
Background
The aim of this study was to evaluate long-term platinum retention in patients treated with cisplatin and oxaliplatin. 相似文献184.
185.
A low copy number cosmid 总被引:8,自引:1,他引:7
A low copy number cosmid was constructed by subcloning the pair of cos sites and the kanamycin resistance gene of pcos2EMBL into pGB2. The resulting cosmid, pPR691, has the pSC101 replicon and specifies resistance to kanamycin, spectinomycin, and streptomycin. pPR691 also carries restriction sites suitable for cloning partial Sau3A digests using the strategy of Bates and Swift (P. F. Bates and R. A. Swift, 1983, Gene 26, 137-146). A library of Salmonella typhimurium chromosomal DNA was made using this cosmid and the rfb gene cluster (map position 42) was isolated from this library. 相似文献
186.
盐胁迫下大豆根组织定量PCR分析中内参基因的选择 总被引:1,自引:0,他引:1
实时荧光定量PCR已广泛用于基因表达的分析, 适当的内参基因选择是获得准确分析结果的关键。在大豆(Glycine max)分子生物学研究中, 逆境响应基因和microRNA (miRNA)表达的内参辅助检测基因均有哪些目前尚不清楚。该研究选用不同盐梯度和时间点组合处理的大豆根组织为材料, 对已报道的其它条件下表达相对稳定的内参基因(ACT、ACT2/7、CYP2、ELF1A、ELF1B、F-Box、TUA和UBC2)以及miRNA内参基因(U6、miR1515a、miR1520c、miR1520d、miR171a和miR171b)的表达情况进行了全面检测; 并采用Δ-Ct、Bestkeeper、NormFinder和Genorm四种方法对检测结果进行了综合分析, 发现ELF1B和CYP2适合作为大豆根系盐胁迫响应基因研究的内参基因, miR1515a和U6适合作为盐胁迫下大豆根组织miRNA研究的内参。上述研究结果为大豆盐胁迫响应基因和miRNA表达及其进一步的功能研究奠定了基础。 相似文献
187.
Syeda Mehpara Farhat Aamra Mahboob Ghazala Iqbal Touqeer Ahmed 《Biological trace element research》2017,177(1):115-121
Aluminum is associated with etiology of many neurodegenerative diseases specially Alzheimer’s disease. Chronic exposure to aluminum via drinking water results in aluminum deposition in the brain that leads to cognitive deficits. The study aimed to determine the effects of aluminum on cholinergic biomarkers, i.e., acetylcholine level, free choline level, and choline acetyltransferase gene expression, and how cholinergic deficit affects novel object recognition and sociability in mice. Mice were treated with AlCl3 (250 mg/kg). Acetylcholine level, free choline level, and choline acetyltransferase gene expression were determined in cortex, hippocampus, and amygdala. The mice were subjected to behavior tests (novel object recognition and social novelty preference) to assess memory deficits. The acetylcholine level in cortex and hippocampus was significantly reduced in aluminum-treated animals, as compared to cortex and hippocampus of control animals. Acetylcholine level in amygdala of aluminum-treated animals remained unchanged. Free choline level in all the three brain parts was found unaltered in aluminum-treated mice. The novel object recognition memory was severely impaired in aluminum-treated mice, as compared to the control group. Similarly, animals treated with aluminum showed reduced sociability compared to the control mice group. Our study demonstrates that aluminum exposure via drinking water causes reduced acetylcholine synthesis in spite of normal free choline availability. This deficit is caused by reduced recycling of acetylcholine due to lower choline acetyltransferase level. This cholinergic hypofunction leads to cognitive and memory deficits. Moreover, hippocampus is the most affected brain part after aluminum intoxication. 相似文献
188.
Shiqian Zhang Changzhen Liu Peng Huang Jingshan Ren Peifu Tang Bin Gao 《Archives of biochemistry and biophysics》2009,487(1):49-53
Receptor activator of nuclear factor-kappa B (RANK) and its ligand, RANKL play critical roles in bone re-modeling, immune function, vascular disease and mammary gland development. To study the interaction of RANK and RANKL, we have expressed both extracellular domain of RANK and ectodomain of RANKL using Escherichia coli expression system. RANK was expressed as an inclusion body first which properly refolded later, while RANKL was initially produced as a GST fusion protein, after which the GST was removed by enzyme digestion. Soluble RANK existed as a monomer while RANKL was seen as a trimer in solution, demonstrated by gel filtration chromatography and cross-linking experiment. The recombinant RANK and RANKL could bind to each other and the binding affinity of RANKL for RANK was measured with surface plasmon resonance technology and KD value is about 1.09 × 10−10 M. 相似文献
189.
Brüser T 《Applied microbiology and biotechnology》2007,76(1):35-45
The biotechnological production of recombinant proteins is challenged by processes that decrease the yield, such as protease
action, aggregation, or misfolding. Today, the variation of strains and vector systems or the modulation of inducible promoter
activities is commonly used to optimize expression systems. Alternatively, aggregation to inclusion bodies may be a desired
starting point for protein isolation and refolding. The discovery of the twin-arginine translocation (Tat) system for folded
proteins now opens new perspectives because in most cases, the Tat machinery does not allow the passage of unfolded proteins.
This feature of the Tat system can be exploited for biotechnological purposes, as expression systems may be developed that
ensure a virtually complete folding of a recombinant protein before purification. This review focuses on the characteristics
that make recombinant Tat systems attractive for biotechnology and discusses problems and possible solutions for an efficient
translocation of folded proteins. 相似文献
190.
Linda H Münger Mar Garcia-Aloy Rosa Vázquez-Fresno Doreen Gille Albert Remus R Rosana Anna Passerini María-Trinidad Soria-Florido Grégory Pimentel Tanvir Sajed David S Wishart Cristina Andres Lacueva Guy Vergères Giulia Praticò 《Genes & nutrition》2018,13(1):26
Dairy and egg products constitute an important part of Western diets as they represent an excellent source of high-quality proteins, vitamins, minerals and fats. Dairy and egg products are highly diverse and their associations with a range of nutritional and health outcomes are therefore heterogeneous. Such associations are also often weak or debated due to the difficulty in establishing correct assessments of dietary intake. Therefore, in order to better characterize associations between the consumption of these foods and health outcomes, it is important to identify reliable biomarkers of their intake. Biomarkers of food intake (BFIs) provide an accurate measure of intake, which is independent of the memory and sincerity of the subjects as well as of their knowledge about the consumed foods. We have, therefore, conducted a systematic search of the scientific literature to evaluate the current status of potential BFIs for dairy products and BFIs for egg products commonly consumed in Europe. Strikingly, only a limited number of compounds have been reported as markers for the intake of these products and none of them have been sufficiently validated. A series of challenges hinders the identification and validation of BFI for dairy and egg products, in particular, the heterogeneous composition of these foods and the lack of specificity of the markers identified so far. Further studies are, therefore, necessary to validate these compounds and to discover new candidate BFIs. Untargeted metabolomic strategies may allow the identification of novel biomarkers, which, when taken separately or in combination, could be used to assess the intake of dairy and egg products. 相似文献