排序方式: 共有27条查询结果,搜索用时 0 毫秒
1.
Romain Philippe Etienne Paux Isabelle Bertin Pierre Sourdille Fréderic Choulet Christel Laugier Hana ?imková Jan ?afá? Arnaud Bellec Sonia Vautrin Zeev Frenkel Federica Cattonaro Federica Magni Simone Scalabrin Mihaela M Martis Klaus FX Mayer Abraham Korol Hélène Bergès Jaroslav Dole?el Catherine Feuillet 《Genome biology》2013,14(6):R64
Background
As for other major crops, achieving a complete wheat genome sequence is essential for the application of genomics to breeding new and improved varieties. To overcome the complexities of the large, highly repetitive and hexaploid wheat genome, the International Wheat Genome Sequencing Consortium established a chromosome-based strategy that was validated by the construction of the physical map of chromosome 3B. Here, we present improved strategies for the construction of highly integrated and ordered wheat physical maps, using chromosome 1BL as a template, and illustrate their potential for evolutionary studies and map-based cloning.Results
Using a combination of novel high throughput marker assays and an assembly program, we developed a high quality physical map representing 93% of wheat chromosome 1BL, anchored and ordered with 5,489 markers including 1,161 genes. Analysis of the gene space organization and evolution revealed that gene distribution and conservation along the chromosome results from the superimposition of the ancestral grass and recent wheat evolutionary patterns, leading to a peak of synteny in the central part of the chromosome arm and an increased density of non-collinear genes towards the telomere. With a density of about 11 markers per Mb, the 1BL physical map provides 916 markers, including 193 genes, for fine mapping the 40 QTLs mapped on this chromosome.Conclusions
Here, we demonstrate that high marker density physical maps can be developed in complex genomes such as wheat to accelerate map-based cloning, gain new insights into genome evolution, and provide a foundation for reference sequencing. 相似文献2.
3.
Peter?Kosarev Klaus?FX?Mayer Christian?S?HardtkeEmail author 《Genome biology》2002,3(4):research0016.1
Background
In computational analysis, the RING-finger domain is one of the most frequently detected domains in the Arabidopsis proteome. In fact, it is more abundant in Arabidopsis than in other eukaryotic genomes. However, computational analysis might classify ambiguous domains of the closely related PHD and LIM motifs as RING domains by mistake. Thus, we set out to define an ordered set of Arabidopsis RING domains by evaluating predicted domains on the basis of recent structural data.Results
Inspection of the proteome with a current InterPro release predicts 446 RING domains. We evaluated each detected domain and as a result eliminated 59 false positives. The remaining 387 domains were grouped by cluster analysis and according to their metal-ligand arrangement. We further defined novel patterns for additional computational analyses of the proteome. They were based on recent structural data that enable discrimination between the related RING, PHD and LIM domains. These patterns allow us to predict with different degrees of certainty whether a particular domain is indeed likely to form a RING finger.Conclusions
In summary, 387 domains have a significant potential to form a RING-type cross-brace structure. Many of these RING domains overlap with predicted PHD domains; however, the RING domain signature mostly prevails. Thus, the abundance of PHD domains in Arabidopsis has been significantly overestimated. Cluster analysis of the RING domains defines groups of proteins, which frequently show significant similarity outside the RING domain. These groups document a common evolutionary origin of their members and potentially represent genes of overlapping functionality.4.
This study investigates the effect of Mg(2+) bound to the DNA major groove on DNA structure and dynamics. The analysis of a comprehensive dataset of B-DNA crystallographic structures shows that divalent cations are preferentially located in the DNA major groove where they interact with successive bases of (A/G)pG and the phosphate group of 5'-CpA or TpG. Based on this knowledge, molecular dynamics simulations were carried out on a DNA oligomer without or with Mg(2+) close to an ApG step. These simulations showed that the hydrated Mg(2+) forms a stable intra-strand cross-link between the two purines in solution. ApG generates an electrostatic potential in the major groove that is particularly attractive for cations; its intrinsic conformation is well-adapted to the formation of water-mediated hydrogen bonds with Mg(2+). The binding of Mg(2+) modulates the behavior of the 5'-neighboring step by increasing the BII (ε-ζ>0°) population of its phosphate group. Additional electrostatic interactions between the 5'-phosphate group and Mg(2+) strengthen both the DNA-cation binding and the BII character of the 5'-step. Cation binding in the major groove may therefore locally influence the DNA conformational landscape, suggesting a possible avenue for better understanding how strong DNA distortions can be stabilized in protein-DNA complexes. 相似文献
5.
Norepinephrine-induced Ca2+ waves depend on InsP3 and ryanodine receptor activation in vascular myocytes 总被引:1,自引:0,他引:1
Boittin Francois-Xavier; Macrez Nathalie; Halet Guillaume; Mironneau Jean 《American journal of physiology. Cell physiology》1999,277(1):C139
In rat portal veinmyocytes, Ca2+ signals can begenerated by inositol 1,4,5-trisphosphate(InsP3)- and ryanodine-sensitive Ca2+ release channels, which arelocated on the same intracellular store. Using a laser scanningconfocal microscope associated with the patch-clamp technique, weshowed that propagated Ca2+ wavesevoked by norepinephrine (in the continuous presence of oxodipine) werecompletely blocked after internal application of ananti-InsP3 receptor antibody.These propagated Ca2+ waves werealso reduced by ~50% and transformed in homogenous Ca2+ responses after applicationof an anti-ryanodine receptor antibody or ryanodine. All-or-noneCa2+ waves obtained withincreasing concentrations of norepinephrine were transformed in adose-response relationship with a Hill coefficient close to unity afterryanodine receptor inhibition. Similar effects of the ryanodinereceptor inhibition were observed on the norepinephrine- andACh-induced Ca2+ responses innon-voltage-clamped portal vein and duodenal myocytes and on thenorepinephrine-induced contraction. Taken together, these results showthat ryanodine-sensitive Ca2+release channels are responsible for the fast propagation of Ca2+ responses evoked by variousneurotransmitters producing InsP3 in vascular and visceral myocytes. 相似文献
6.
7.
María Mu?oz-Amatriaín Steven R Eichten Thomas Wicker Todd A Richmond Martin Mascher Burkhard Steuernagel Uwe Scholz Ruvini Ariyadasa Manuel Spannagl Thomas Nussbaumer Klaus FX Mayer Stefan Taudien Matthias Platzer Jeffrey A Jeddeloh Nathan M Springer Gary J Muehlbauer Nils Stein 《Genome biology》2013,14(6):R58
Background
There is growing evidence for the prevalence of copy number variation (CNV) and its role in phenotypic variation in many eukaryotic species. Here we use array comparative genomic hybridization to explore the extent of this type of structural variation in domesticated barley cultivars and wild barleys.Results
A collection of 14 barley genotypes including eight cultivars and six wild barleys were used for comparative genomic hybridization. CNV affects 14.9% of all the sequences that were assessed. Higher levels of CNV diversity are present in the wild accessions relative to cultivated barley. CNVs are enriched near the ends of all chromosomes except 4H, which exhibits the lowest frequency of CNVs. CNV affects 9.5% of the coding sequences represented on the array and the genes affected by CNV are enriched for sequences annotated as disease-resistance proteins and protein kinases. Sequence-based comparisons of CNV between cultivars Barke and Morex provided evidence that DNA repair mechanisms of double-strand breaks via single-stranded annealing and synthesis-dependent strand annealing play an important role in the origin of CNV in barley.Conclusions
We present the first catalog of CNVs in a diploid Triticeae species, which opens the door for future genome diversity research in a tribe that comprises the economically important cereal species wheat, barley, and rye. Our findings constitute a valuable resource for the identification of CNV affecting genes of agronomic importance. We also identify potential mechanisms that can generate variation in copy number in plant genomes. 相似文献8.
Basset O Boittin FX Dorchies OM Chatton JY van Breemen C Ruegg UT 《The Journal of biological chemistry》2004,279(45):47092-47100
In skeletal muscle cells, plasma membrane depolarization causes a rapid calcium release from the sarcoplasmic reticulum through ryanodine receptors triggering contraction. In Duchenne muscular dystrophy (DMD), a lethal disease that is caused by the lack of the cytoskeletal protein dystrophin, the cytosolic calcium concentration is known to be increased, and this increase may lead to cell necrosis. Here, we used myotubes derived from control and mdx mice, the murine model of DMD, to study the calcium responses induced by nicotinic acetylcholine receptor stimulation. The photoprotein aequorin was expressed in the cytosol or targeted to the plasma membrane as a fusion protein with the synaptosome-associated protein SNAP-25, thus allowing calcium measurements in a restricted area localized just below the plasma membrane. The carbachol-induced calcium responses were 4.5 times bigger in dystrophic myotubes than in control myotubes. Moreover, in dystrophic myotubes the carbachol-mediated calcium responses measured in the subsarcolemmal area were at least 10 times bigger than in the bulk cytosol. The initial calcium responses were due to calcium influx into the cells followed by a fast refilling/release phase from the sarcoplasmic reticulum. In addition and unexpectedly, the inositol 1,4,5-trisphosphate receptor pathway was involved in these calcium signals only in the dystrophic myotubes. This surprising involvement of this calcium release channel in the excitation-contraction coupling could open new ways for understanding exercise-induced calcium increases and downstream muscle degeneration in mdx mice and, therefore, in DMD. 相似文献
9.
François-Xavier Boittin George Shapovalov Urs T. Ruegg 《Biochemical and biophysical research communications》2010,391(1):401-406
Duchenne muscular dystrophy is an inherited disease caused by the absence of dystrophin, a structural protein normally located under the sarcolemma of skeletal muscle fibers. Muscle degeneration occurring in this disease is thought to be partly caused by increased Ca2+ entry through sarcolemmal cationic channels. Using the Mn2+ quench method, we show here that Mn2+ entry triggered by Ca2+ store depletion but not basal Mn2+ entry relies on Ca2+-independent PLA2 (iPLA2) activity in dystrophic fibers isolated from a murine model of Duchenne muscular dystrophy, the mdx5cv mouse. iPLA2 was found to be localized in the vicinity of the sarcolemma and consistently, the iPLA2 lipid product lysophosphatidylcholine was found to trigger Ca2+ entry through sarcolemmal channels, suggesting that it acts as an intracellular messenger responsible for store-operated channels opening in dystrophic fibers. Our results suggest that inhibition of iPLA2 and lysophospholipid production may be of interest to reduce Ca2+ entry and subsequent degeneration of dystrophic muscle. 相似文献
10.