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Background
Micro-biological research relies on the use of model organisms that act as representatives of their species or subspecies, these are frequently well-characterized laboratory strains. However, it has often become apparent that the model strain initially chosen does not represent important features of the species. For micro-organisms, the diversity of their genomes is such that even the best possible choice of initial strain for sequencing may not assure that the genome obtained adequately represents the species. To acquire information about a species' genome as efficiently as possible, we require a method to choose strains for analysis on the basis of how well they represent the species. 相似文献3.
In the soybean (Glycine max (L.) Merr.), the gene combination Fg1 Fg3 is responsible for the glycosylation in the biosynthesis of kaempferol triglucoside (K9) in leaves. The presence of K9 is associated with reduction in chlorophyll content, specific leaf mass, photosynthetic rate and stomatal frequency. Blocking the action of Fg1 Fg3 with the magenta flower gene wm prevents formation of K9 and restores leaf traits to normal. A direct effect of K9 on leaf development is postulated. 相似文献
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Stomatal numbers of soybean and response to water stress 总被引:2,自引:0,他引:2
B. R. Buttery C. S. Tan R. I. Buzzell J. D. Gaynor D. C. MacTavish 《Plant and Soil》1993,149(2):283-288
The relationship among stomatal density, photosynthetic rate, leaf conductance, plant growth, bean yield and kaempferol triglucoside (K9) in the leaves of soybean (Glycine max (L.) Merr.) was examined in two field tests. K9 in the leaves was associated with reduced stomatal density, reduced photosynthetic rate, reduced stomatal conductance, reduced plant weight and lower bean yield. Plants with high stomatal frequency (lacking K9) were better able to take advantage of increased water supply by increasing stomatal conductance (upper surface), transpiration and bean yield. Plants with low stomatal frequency (with K9) were unresponsive to irrigation and in this sense were more tolerant of water stress, but their overall yield was low. 相似文献
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Paul D. Hartley Richard L. Tillett David P. AuCoin Joel R. Sevinsky Yanji Xu Andrew Gorzalski Mark Pandori Erin Buttery Holly Hansen Michael A. Picker Cyprian C. Rossetto Subhash C. Verma 《遗传学报》2021,48(1):40-51
Patients with signs of COVID-19 were tested through diagnostic RT-PCR for SARS-CoV-2 using RNA extracted from the nasopharyngeal/nasal swabs.To determine the variants of SARS-CoV-2 circulating in the state of Nevada,specimens from 200 COVID-19 patients were sequenced through our robust sequencing platform,which enabled sequencing of SARS-CoV-2 from specimens with even very low viral loads,without the need of culture-based amplification.High genome coverage allowed the identification of single and multi-nucleotide variants in SARS-CoV-2 in the community and their phylogenetic relationships with other variants present during the same period of the outbreak.We report the occurrence of a novel mutation at 323aa (314aa of orf1b) of nsp12 (RNA-dependent RNA polymerase) changed to phenylalanine(F) from proline (P),in the first reported isolate of SARS-CoV-2,Wuhan-Hu-1.This 323F variant was present at a very high frequency in Northern Nevada.Structural modeling determined this mutation in the interface domain,which is important for the association of accessory proteins required for the polymerase.In conclusion,we report the introduction of specific SARS-CoV-2 variants at very high frequency in distinct geographic locations,which is important for understanding the evolution and circulation of SARS-CoV-2variants of public health importance,while it circulates in humans. 相似文献
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Different values have resulted in conflicts between anglers and conservation lobbies in the management of trout in South Africa. Key to the conflict is the demarcation of boundaries to areas in which brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss currently occur, or are likely to establish following stocking for angling. To provide a longer-term perspective on these areas, we developed models to link salmonid biological thermal thresholds to elevation. These, when applied spatially using a digital elevation model with a probability of occurrence model, provided the basis for estimating potentially available thermal habitat for these two cold water species. Here, we acknowledge that other variables (stocking history; river connectivity) also play a role in understanding trout distributions. Using a simple scenario of an increase in mean daily water temperatures of 2 °C, we demonstrated that both brown and rainbow trout are likely to exhibit considerable range reductions in the future. Because it is possible that these range restrictions will result in an increasing desire to introduce trout into areas above their current distribution limits for the maintenance of angling opportunities, conservation managers should prioritise these areas, with management interventions seeking to understand what will help to limit introductions. 相似文献
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Relvas JB Setzu A Baron W Buttery PC LaFlamme SE Franklin RJ ffrench-Constant C 《Current biology : CB》2001,11(13):1039-1043
Myelination represents a remarkable example of cell specialization and cell-cell interaction in development. During this process, axons are wrapped by concentric layers of cell membrane derived either from central nervous system (CNS) oligodendrocytes or peripheral nervous system Schwann cells. In the CNS, oligodendrocytes elaborate a membranous extension with an area of more than 1000 times that of the cell body. The mechanisms regulating this change in cell shape remain poorly understood. Signaling mechanisms regulated by cell surface adhesion receptors of the integrin family represent likely candidates. Integrins link the extracellular environment of the cell with both intracellular signaling molecules and the cytoskeleton and have been shown to regulate the activity of GTPases implicated in the control of cell shape. Our previous work has established that oligodendrocytes and their precursors express a limited repertoire of integrins. One of these, the alpha6beta1 laminin receptor, can interact with laminin-2 substrates to enhance oligodendrocyte myelin membrane formation in cell culture. However, these experiments do not address the important question of integrin function during myelination in vivo, nor do they define the respective roles of the alpha and beta subunits in the signaling pathways involved. Here, we use a dominant-negative approach to provide, for the first time, evidence that beta1 integrin function is required for myelination in vivo and use chimeric integrins to dissect apart the roles of the extracellular and cytoplasmic domains of the alpha6 subunit in the signaling pathways of myelination. 相似文献
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Xynos ID Edgar AJ Buttery LD Hench LL Polak JM 《Biochemical and biophysical research communications》2000,276(2):461-465
Bioglass 45S5 is an osteoproductive material, which resorbs by releasing its constitutive ions into solution. Treatment with the ionic products of Bioglass 45S5 dissolution in DMEM for 4 days increased human osteoblast proliferation to 155% of control. Two days after treatment, differential gene expression was analyzed by cDNA microarrays. Expression of a potent osteoblast mitogenic growth factor, insulin-like growth factor II (IGF-II), was increased to 290%. Additionally, there was a 168% increase in the concentration of unbound IGF-II protein in the conditioned media of treated osteoblasts. Expression levels of IGFBP-3, an IGF-II carrier protein, metalloproteinase-2 and cathepsin-D were also increased to 200, 340, and 310% of control levels, respectively. Metalloproteinase-2 and cathepsin-D are proteases that cleave IGF-II from its carrier proteins, resulting in the release of the unbound biologically active IGF-II. We suggest that the stimulatory effect of the ionic products of Bioglass 45S5 dissolution on osteoblast proliferation may be mediated by IGF-II. 相似文献
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