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1.
Response of microbial populations to environmental disturbance 总被引:18,自引:0,他引:18
Taxonomic and genetic diversities of microbial communities disturbed by chemical pollutants were lower than in undisturbed
reference communities. The dominant populations within the disturbed communities had enhanced physiological tolerances and
substrate utilization capabilities, indicating that generalized physiological versatility is an adaptive characteristic of
populations that successfully compete within disturbed communities. 相似文献
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M F Thorel M Krichevsky V V Lévy-Frébault 《International journal of systematic bacteriology》1990,40(3):254-260
We performed a numerical taxonomy analysis of 38 Mycobacterium paratuberculosis and related mycobacterial strains, including wood pigeon mycobacteria; this analysis was based on 22 tests, which were selected for their potential discriminative value from a total of 51 tests studied and produced four well-defined clusters. Cluster 1 contained the M. paratuberculosis strains, including two strains isolated from Crohn's disease patients; cluster 2 contained Mycobacterium avium and Mycobacterium intracellulare reference strains; cluster 3 consisted of the wood pigeon mycobacteria; and the only strain in cluster 4 was M. paratuberculosis 316F, which is used for antigen and vaccine production. Strains in cluster 1 were mycobactin dependent even when they were subcultured, whereas strains in cluster 3 were unable to grow on egg medium and their growth was stimulated by pH 5.5. Growth stimulation by pyruvate, resistance to D-cycloserine (50 micrograms/ml), and alkaline phosphatase activity also were characteristics that were useful for discriminating between clusters 1 and 3. The results of previous DNA-DNA hybridization studies have demonstrated that M. avium Chester 1901, M. paratuberculosis Bergey et al. 1923, and the wood pigeon mycobacteria belong to a single genomic species, and we propose that the name of this species should be M. avium. On the basis of the results of previous genomic analyses based on restriction fragment length, the results of polymorphism studies, and DNA patterns determined by field inversion gel electrophoresis as well as the results of our phenotypic study, we propose that the species should be divided into subspecies which correspond to pathogenicity and host range characteristics.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
3.
W R Moyle M M Matzuk R K Campbell E Cogliani D M Dean-Emig A Krichevsky R W Barnett I Boime 《The Journal of biological chemistry》1990,265(15):8511-8518
The glycoprotein hormones are a family of conserved heterodimeric proteins which share a common alpha subunit but differ in their hormone-specific beta subunits. We used chimeras of human chorionic gonadotropin (hCG) and luteinizing hormone (hLH) beta subunits to identify residues which enable monoclonal antibodies (mAb) to distinguish the two hormones. The LH beta-CG beta chimeras appeared to fold similar to hCG beta, since they combined with hCG alpha and, depending on their sequences, were recognized by hCG-selective mAbs. Amino acid residues Arg8-Arg10,Gly47-Ala51, and Gln89-Leu92 form a major epitope region and appear to be adjacent to each other on the surface of hCG beta. Gly47-Ala51 and Gln89-Leu92 are recognized by dimer-specific mAbs while Arg8-Arg10 is recognized by mAbs which have highest affinity for the free beta subunit. These observations suggest that the conformation of this region of the beta subunit changes when the alpha and beta subunits combine. Residues which are C-terminal of Asp112 form a second epitope domain. mAbs to the third domain distinguish hCG beta and hLH beta by the presence of Asn77 in hCG beta and can be detected after hCG binds to receptors. These findings were used to develop a model of hCG beta which predicts the locations of these residues and their positions relative to the alpha subunit and receptor interfaces. 相似文献
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New cases of trepanations from the 5th to 3rd millennia BC in Southern Russia in the context of previous research: Possible evidence for a ritually motivated tradition of cranial surgery? 下载免费PDF全文
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Mian Abdur Rehman Arif Sajid Shokat Jörg Plieske Martin Ganal Ulrike Lohwasser Yuriy V. Chesnokov Nataliya V. Kocherina Pawan Kulwal Neeraj Kumar Patrick E. McGuire Mark E. Sorrells Calvin O. Qualset Andreas Börner 《The Plant journal : for cell and molecular biology》2021,108(4):960-976
The continuous increase in global population prompts increased wheat production. Future wheat (Triticum aestivum L.) breeding will heavily rely on dissecting molecular and genetic bases of wheat yield and related traits which is possible through the discovery of quantitative trait loci (QTLs) in constructed populations, such as recombinant inbred lines (RILs). Here, we present an evaluation of 92 RILs in a bi-parental RIL mapping population (the International Triticeae Mapping Initiative Mapping Population [ITMI/MP]) using newly generated phenotypic data in 3-year experiments (2015), older phenotypic data (1997–2009), and newly created single nucleotide polymorphism (SNP) marker data based on 92 of the original RILs to search for novel and stable QTLs. Our analyses of more than 15 unique traits observed in multiple experiments included analyses of 46 traits in three environments in the USA, 69 traits in eight environments in Germany, 149 traits in 10 environments in Russia, and 28 traits in four environments in India (292 traits in 25 environments) with 7584 SNPs (292 × 7584 = 2 214 528 data points). A total of 874 QTLs were detected with limit of detection (LOD) scores of 2.01–3.0 and 432 QTLs were detected with LOD > 3.0. Moreover, 769 QTLs could be assigned to 183 clusters based on the common markers and relative proximity of related QTLs, indicating gene-rich regions throughout the A, B, and D genomes of common wheat. This upgraded genotype–phenotype information of ITMI/MP can assist breeders and geneticists who can make crosses with suitable RILs to improve or investigate traits of interest. 相似文献
9.
Rheal A. Towner Nataliya Smith Debra Saunders Patricia Coutinho De Souza Leah Henry Florea Lupu Robert Silasi-Mansat Marilyn Ehrenshaft Ronald P. Mason Sandra E. Gomez-Mejiba Dario C. Ramirez 《生物化学与生物物理学报:疾病的分子基础》2013,1832(12):2153-2161
Free radicals play a major role in gliomas. By combining immuno-spin-trapping (IST) and molecular magnetic resonance imaging (mMRI), in vivo levels of free radicals were detected within mice bearing orthotopic GL261 gliomas. The nitrone spin trap DMPO (5,5-dimethyl pyrroline N-oxide) was administered prior to injection of an anti-DMPO probe (anti-DMPO antibody covalently bound to a bovine serum albumin (BSA)–Gd (gadolinium)-DTPA (diethylene triamine penta acetic acid)–biotin MRI contrast agent) to trap tumor-associated free radicals. mMRI detected the presence of anti-DMPO adducts by either a significant sustained increase (p < 0.001) in MR signal intensity or a significant decrease (p < 0.001) in T1 relaxation, measured as %T1 change. In vitro assessment of the anti-DMPO probe indicated a significant decrease (p < 0.0001) in T1 relaxation in GL261 cells that were oxidatively stressed with hydrogen peroxide, compared to controls. The biotin moiety of the anti-DMPO probe was targeted with fluorescently-labeled streptavidin to locate the anti-DMPO probe in excised brain tissues. As a negative control a non-specific IgG antibody covalently bound to the albumin–Gd-DTPA–biotin construct was used. DMPO adducts were also confirmed in tumor tissue from animals administered DMPO, compared to non-tumor brain tissue. GL261 gliomas were found to have significantly increased malondialdehyde (MDA) protein adducts (p < 0.001) and 3-nitrotyrosine (3-NT) (p < 0.05) compared to normal mouse brain tissue, indicating increased oxidized lipids and proteins, respectively. Co-localization of the anti-DMPO probe with either 3-NT or 4-hydroxynonenal was also observed. This is the first report regarding the detection of in vivo levels of free radicals from a glioma model. 相似文献
10.
Nataliya Di Donato Ying Y. Jean A. Murat Maga Briana D. Krewson Alison B. Shupp Maria I. Avrutsky Achira Roy Sarah Collins Carissa Olds Rebecca A. Willert Agnieszka M. Czaja Rachel Johnson Jessi A. Stover Steven Gottlieb Deborah Bartholdi Anita Rauch Amy Goldstein Victoria Boyd-Kyle Kimberly A. Aldinger Ghayda M. Mirzaa Anke Nissen Karlla W. Brigatti Erik G. Puffenberger Kathleen J. Millen Kevin A. Strauss William B. Dobyns Carol M. Troy Robert N. Jinks 《American journal of human genetics》2016,99(5):1117-1129