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排序方式: 共有351条查询结果,搜索用时 15 毫秒
91.
92.
High-throughput SNP genotyping on universal bead arrays 总被引:16,自引:0,他引:16
Shen R Fan JB Campbell D Chang W Chen J Doucet D Yeakley J Bibikova M Wickham Garcia E McBride C Steemers F Garcia F Kermani BG Gunderson K Oliphant A 《Mutation research》2005,573(1-2):70-82
We have developed a flexible, accurate and highly multiplexed SNP genotyping assay for high-throughput genetic analysis of large populations on a bead array platform. The novel genotyping system combines high assay conversion rate and data quality with >1500 multiplexing, and Array of Arrays formats. Genotyping assay oligos corresponding to specific SNP sequences are each linked to a unique sequence (address) that can hybridize to its complementary strand on universal arrays. The arrays are made of beads located in microwells of optical fiber bundles (Sentrix Array Matrix) or silicon slides (Sentrix BeadChip). The optical fiber bundles are further organized into a matrix that matches a 96-well microtiter plate. The arrays on the silicon slides are multi-channel pipette compatible for loading multiple samples onto a single silicon slide. These formats allow many samples to be processed in parallel. This genotyping system enables investigators to generate approximately 300,000 genotypes per day with minimal equipment requirements and greater than 1.6 million genotypes per day in a robotics-assisted process. With a streamlined and comprehensive assay, this system brings a new level of flexibility, throughput, and affordability to genetic research. 相似文献
93.
The digenetic trematode Bucephalus anguillae n. sp. is described from the intestine of eel, Anguilla anguilla L., originating from a brackish water fish farm on the Italian coast of the Adriatic Sea. The new taxon is 1 of 12 Bucephalus species characterized by an anterior rhynchus surrounded by 7 tentacular appendages, each when fully protruded with 2 prongs. Scanning electron microscopy reveals, for the first time in a Bucephalus species, the crescent-shaped, unspined field located between the rhynchus and the dorsal tentacles. A comparison of B. anguillae n. sp. with 11 congeneric species revealed its remarkable similarity with B. polymorphus Baer, 1827; however, the new species has a larger cirrus sac, larger pharynx, vitelline gland fields not extending the level of pharynx, ovary located in the pharyngeal area rather than fairly posterior to pharynx, smaller testes, relatively wider rhynchus, and tegumental armature comprising slightly larger spines. Multivariate discriminant analyses confirmed a differentiation of B. anguillae from populations of B. polymorphus; the combination of 4 variables, namely cirrus sac length, pharynx width, cirrus sac width, and rhynchus width yielded a total separation of compared species. 相似文献
94.
Molecular cloning and characterization of a cDNA encoding poplar UDP-glucose dehydrogenase,a key gene of hemicellulose/pectin formation 总被引:8,自引:0,他引:8
Johansson H Sterky F Amini B Lundeberg J Kleczkowski LA 《Biochimica et biophysica acta》2002,1576(1-2):53-58
Plant UDP-glucose dehydrogenase (UGDH) is an important enzyme in the formation of hemicellulose and pectin, the components of newly formed cell walls. A cDNA clone (Ugdh) corresponding to UGDH was isolated from a cDNA library prepared from cambial zone of poplar (Populus tremula x tremuloides). Within the 1824-nucleotide (nt)-long clone, an open reading frame encoded a protein of 481 amino acids (aa), with a calculated molecular weight of 53.1 kDa. The derived aa sequence showed 90% and 63% identity with UGDHs from soybean and bovine liver, respectively, and had highly conserved aa motifs believed to be of importance for nt binding and catalytic efficiency. In poplar, the Ugdh corresponds to one or two genes, as found by genomic Southern analysis. The gene was expressed predominantly in differentiating xylem and young leaves, with little expression in the phloem zone of the stem. The expression pattern matched that of UGDH protein, as found by immunoblotting. In leaves, the Ugdh expression was upregulated by a short-term feeding with sucrose, sorbitol and polyethylene glycol, and this effect was to some extent mimicked by light exposure. The data suggest that Ugdh is regulated via an osmoticum-dependent pathway, possibly related to the availability of osmotically active carbohydrate precursors to UDP-glucose, a substrate of UGDH. 相似文献
95.
Mohammad Bahram Tarquin Netherway Clémence Frioux Pamela Ferretti Luis Pedro Coelho Stefan Geisen Peer Bork Falk Hildebrand 《Environmental microbiology》2021,23(1):316-326
Bacteria and fungi are of uttermost importance in determining environmental and host functioning. Despite close interactions between animals, plants, their associated microbiomes, and the environment they inhabit, the distribution and role of bacteria and especially fungi across host and environments as well as the cross-habitat determinants of their community compositions remain little investigated. Using a uniquely broad global dataset of 13 483 metagenomes, we analysed the microbiome structure and function of 25 host-associated and environmental habitats, focusing on potential interactions between bacteria and fungi. We found that the metagenomic relative abundance ratio of bacteria-to-fungi is a distinctive microbial feature of habitats. Compared with fungi, the cross-habitat distribution pattern of bacteria was more strongly driven by habitat type. Fungal diversity was depleted in host-associated communities compared with those in the environment, particularly terrestrial habitats, whereas this diversity pattern was less pronounced for bacteria. The relative gene functional potential of bacteria or fungi reflected their diversity patterns and appeared to depend on a balance between substrate availability and biotic interactions. Alongside helping to identify hotspots and sources of microbial diversity, our study provides support for differences in assembly patterns and processes between bacterial and fungal communities across different habitats. 相似文献
96.
Vilmar Veldre Kessy Abarenkov Mohammad Bahram Florent Martos Marc-Andre Selosse Heidi Tamm Urmas Kõljalg Leho Tedersoo 《Fungal Ecology》2013,6(4):256-268
Fungi from the Ceratobasidiaceae family have important ecological roles as pathogens, saprotrophs, non-mycorrhizal endophytes, orchid mycorrhizal and ectomycorrhizal symbionts, but little is known about the distribution and evolution of these nutritional modes. All public ITS sequences of Ceratobasidiaceae were downloaded from databases, annotated with ecological and taxonomic metadata, and tested for the non-random phylogenetic distribution of nutritional modes. Phylogenetic analysis revealed six main clades within Ceratobasidiaceae and a poor correlation between molecular phylogeny and morphological–cytological characters traditionally used for taxonomy. Sequences derived from soil (representing putative saprotrophs) and orchid mycorrhiza clustered together, but remained distinct from pathogens. All nutritional modes were phylogenetically conserved in the Ceratobasidiaceae based on at least one index. Our analyses suggest that in general, autotrophic orchids form root symbiosis with available Ceratobasidiaceae isolates in soil. Ectomycorrhiza-forming capability has evolved twice within the Ceratobasidiaceae and it had a strong influence on the evolution of mycoheterotrophy and host specificity in certain orchid taxa. 相似文献
97.
Zahra Zandi Bahareh Kashani Davood Bashash Ensieh M. Poursani Seyed A. Mousavi Bahram Chahardoli Seyed H. Ghaffari 《Journal of cellular biochemistry》2020,121(2):1623-1634
Increasing pieces of evidence indicate that inflammatory processes facilitate tumorigenesis; tumor cells simulate the mechanisms by which innate immune cells produce pro-inflammatory cytokines to exploit them for their own survival and proliferation. Toll-like receptor 4 (TLR4), which serves as one of the most well-known receptors on the surface of the immune cells, is often expressed ectopically in the tumor cells resulting in tumor progression, invasion, and chemoresistance. In this study, we examined the anticancer effects of TAK-242, a small molecule inhibitor of TLR4, on different breast cancer cell lines: MCF7, SKBR3, MDA-MB-231, and BT-474. Our results showed that the TLR4 inhibition, as revealed by the downregulation of TLR4 downstream genes, exerted desirable cytotoxicity on the TLR4-expressing cells, at least partly, through the downregulation of EGFR and c-Myc genes. TAK-242 also inhibited the proliferation of anoikis-resistant cells and suppressed the clonal growth of the indicated cells. The results of this study propose a mechanistic pathway by which the inhibition of TLR4 using TAK-242 could augment apoptotic cell death through the alteration of both nuclear factor-кB- and p53-related apoptosis genes in breast cancer cells, especially cells with overexpression of TLR4. Taken together, this study supports the idea that the activation of inflammatory pathways may have a crucial role in breast cancer progression and the inhibition of TLR4 using TAK-242, either as a single agent or in combination, seems to be a novel promising strategy that could be clinically available in foreseeable future. 相似文献
98.
Carbohydrate-active enzymes involved in the secondary cell wall biogenesis in hybrid aspen 下载免费PDF全文
Aspeborg H Schrader J Coutinho PM Stam M Kallas A Djerbi S Nilsson P Denman S Amini B Sterky F Master E Sandberg G Mellerowicz E Sundberg B Henrissat B Teeri TT 《Plant physiology》2005,137(3):983-997
Wood formation is a fundamental biological process with significant economic interest. While lignin biosynthesis is currently relatively well understood, the pathways leading to the synthesis of the key structural carbohydrates in wood fibers remain obscure. We have used a functional genomics approach to identify enzymes involved in carbohydrate biosynthesis and remodeling during xylem development in the hybrid aspen Populus tremula x tremuloides. Microarrays containing cDNA clones from different tissue-specific libraries were hybridized with probes obtained from narrow tissue sections prepared by cryosectioning of the developing xylem. Bioinformatic analyses using the sensitive tools developed for carbohydrate-active enzymes allowed the identification of 25 xylem-specific glycosyltransferases belonging to the Carbohydrate-Active EnZYme families GT2, GT8, GT14, GT31, GT43, GT47, and GT61 and nine glycosidases (or transglycosidases) belonging to the Carbohydrate-Active EnZYme families GH9, GH10, GH16, GH17, GH19, GH28, GH35, and GH51. While no genes encoding either polysaccharide lyases or carbohydrate esterases were found among the secondary wall-specific genes, one putative O-acetyltransferase was identified. These wood-specific enzyme genes constitute a valuable resource for future development of engineered fibers with improved performance in different applications. 相似文献
99.
Bahram Samanfar Stephen J. Molnar Martin Charette Andrew Schoenrock Frank Dehne Ashkan Golshani François Belzile Elroy R. Cober 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2017,130(2):377-390
Key message
E10 is a new maturity locus in soybean and FT4 is the predicted/potential functional gene underlying the locus.Abstract
Flowering and maturity time traits play crucial roles in economic soybean production. Early maturity is critical for north and west expansion of soybean in Canada. To date, 11 genes/loci have been identified which control time to flowering and maturity; however, the molecular bases of almost half of them are not yet clear. We have identified a new maturity locus called “E10” located at the end of chromosome Gm08. The gene symbol E10e10 has been approved by the Soybean Genetics Committee. The e10e10 genotype results in 5–10 days earlier maturity than E10E10. A set of presumed E10E10 and e10e10 genotypes was used to identify contrasting SSR and SNP haplotypes. These haplotypes, and their association with maturity, were maintained through five backcross generations. A functional genomics approach using a predicted protein–protein interaction (PPI) approach (Protein–protein Interaction Prediction Engine, PIPE) was used to investigate approximately 75 genes located in the genomic region that SSR and SNP analyses identified as the location of the E10 locus. The PPI analysis identified FT4 as the most likely candidate gene underlying the E10 locus. Sequence analysis of the two FT4 alleles identified three SNPs, in the 5′UTR, 3′UTR and fourth exon in the coding region, which result in differential mRNA structures. Allele-specific markers were developed for this locus and are available for soybean breeders to efficiently develop earlier maturing cultivars using molecular marker assisted breeding.100.
Dihydrofolate reductase (DHFR) catalyzes the reduction of dihydrofolate to tetrahydrofolate (THF). THF is needed for the action of folate-dependent enzymes and is thus essential for DNA synthesis and methylation. The importance of this reaction is demonstrated by the effectiveness of antifolate medications used to treat cancer by inhibiting DHFR, thereby depleting THF and slowing DNA synthesis and cell proliferation. Due to the pivotal role that DHFR plays in folate metabolism and cancer treatment, changes in the level of DHFR expression can affect susceptibility to a variety of diseases dependent on folate status such as spina bifida and cancer. Likewise, variability in DHFR expression can affect sensitivity to anti-cancer drugs such as the folate antagonist methotrexate. Alterations in DHFR expression can be due to polymorphisms in the DHFR gene. Several variations have recently been described in DHFR, including promoter polymorphisms, the 19-bp deletion allele and variations in 3'UTR. These polymorphisms seem to be functional, affecting mRNA levels through various interesting mechanisms, including regulation through RNA interference. Several groups have assessed the association of these polymorphisms with folate levels, risk of cancer and spina bifida as well as the outcome of diseases treated with MTX. The latter may lead to different treatment schedules, improving treatment efficacy and/or allowing for a reduction in drug side effects. This review will summarize present knowledge regarding the predictive potential of DHFR polymorphisms in disease and treatment. 相似文献