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1.
Plant J ; 117(1): 53-71, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37738381

RESUMO

Seed color is one of the key target traits of domestication and artificial selection in chickpeas due to its implications on consumer preference and market value. The complex seed color trait has been well dissected in several crop species; however, the genetic mechanism underlying seed color variation in chickpea remains poorly understood. Here, we employed an integrated genomics strategy involving QTL mapping, high-density mapping, map-based cloning, association analysis, and molecular haplotyping in an inter-specific RIL mapping population, association panel, wild accessions, and introgression lines (ILs) of Cicer gene pool. This delineated a MATE gene, CaMATE23, encoding a Transparent Testa (TT) and its natural allele (8-bp insertion) and haplotype underlying a major QTL governing seed color on chickpea chromosome 4. Signatures of selective sweep and a strong purifying selection reflected that CaMATE23, especially its 8-bp insertion natural allelic variant, underwent selection during chickpea domestication. Functional investigations revealed that the 8-bp insertion containing the third cis-regulatory RY-motif element in the CaMATE23 promoter is critical for enhanced binding of CaFUSCA3 transcription factor, a key regulator of seed development and flavonoid biosynthesis, thereby affecting CaMATE23 expression and proanthocyanidin (PA) accumulation in the seed coat to impart varied seed color in chickpea. Consequently, overexpression of CaMATE23 in Arabidopsis tt12 mutant partially restored the seed color phenotype to brown pigmentation, ascertaining its functional role in PA accumulation in the seed coat. These findings shed new light on the seed color regulation and evolutionary history, and highlight the transcriptional regulation of CaMATE23 by CaFUSCA3 in modulating seed color in chickpea. The functionally relevant InDel variation, natural allele, and haplotype from CaMATE23 are vital for translational genomic research, including marker-assisted breeding, for developing chickpea cultivars with desirable seed color that appeal to consumers and meet global market demand.


Assuntos
Cicer , Cicer/metabolismo , Locos de Características Quantitativas/genética , Alelos , Domesticação , Polimorfismo de Nucleotídeo Único , Melhoramento Vegetal , Sementes/genética
2.
Plant Physiol ; 191(3): 1884-1912, 2023 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-36477336

RESUMO

Identifying potential molecular tags for drought tolerance is essential for achieving higher crop productivity under drought stress. We employed an integrated genomics-assisted breeding and functional genomics strategy involving association mapping, fine mapping, map-based cloning, molecular haplotyping and transcript profiling in the introgression lines (ILs)- and near isogenic lines (NILs)-based association panel and mapping population of chickpea (Cicer arietinum). This combinatorial approach delineated a bHLH (basic helix-loop-helix) transcription factor, CabHLH10 (Cicer arietinum bHLH10) underlying a major QTL, along with its derived natural alleles/haplotypes governing yield traits under drought stress in chickpea. CabHLH10 binds to a cis-regulatory G-box promoter element to modulate the expression of RD22 (responsive to desiccation 22), a drought/abscisic acid (ABA)-responsive gene (via a trans-expression QTL), and two strong yield-enhancement photosynthetic efficiency (PE) genes. This, in turn, upregulates other downstream drought-responsive and ABA signaling genes, as well as yield-enhancing PE genes, thus increasing plant adaptation to drought with reduced yield penalty. We showed that a superior allele of CabHLH10 introgressed into the NILs improved root and shoot biomass and PE, thereby enhancing yield and productivity during drought without compromising agronomic performance. Furthermore, overexpression of CabHLH10 in chickpea and Arabidopsis (Arabidopsis thaliana) conferred enhanced drought tolerance by improving root and shoot agro-morphological traits. These findings facilitate translational genomics for crop improvement and the development of genetically tailored, climate-resilient, high-yielding chickpea cultivars.


Assuntos
Cicer , Locos de Características Quantitativas , Locos de Características Quantitativas/genética , Alelos , Cicer/genética , Cicer/metabolismo , Ácido Abscísico/metabolismo , Resistência à Seca , Melhoramento Vegetal , Secas , Estresse Fisiológico/genética
3.
J Exp Bot ; 73(22): 7255-7272, 2022 12 08.
Artigo em Inglês | MEDLINE | ID: mdl-36006832

RESUMO

'QTL-hotspot' is a genomic region on linkage group 04 (CaLG04) in chickpea (Cicer arietinum) that harbours major-effect quantitative trait loci (QTLs) for multiple drought-adaptive traits, and it therefore represents a promising target for improving drought adaptation. To investigate the mechanisms underpinning the positive effects of 'QTL-hotspot' on seed yield under drought, we introgressed this region from the ICC 4958 genotype into five elite chickpea cultivars. The resulting introgression lines (ILs) and their parents were evaluated in multi-location field trials and semi-controlled conditions. The results showed that the 'QTL-hotspot' region improved seed yield under rainfed conditions by increasing seed weight, reducing the time to flowering, regulating traits related to canopy growth and early vigour, and enhancing transpiration efficiency. Whole-genome sequencing data analysis of the ILs and parents revealed four genes underlying the 'QTL-hotspot' region associated with drought adaptation. We validated diagnostic KASP markers closely linked to these genes using the ILs and their parents for future deployment in chickpea breeding programs. The CaTIFY4b-H2 haplotype of a potential candidate gene CaTIFY4b was identified as the superior haplotype for 100-seed weight. The candidate genes and superior haplotypes identified in this study have the potential to serve as direct targets for genetic manipulation and selection for chickpea improvement.


Assuntos
Cicer , Cicer/genética , Genômica
4.
Bioorg Med Chem Lett ; 76: 129008, 2022 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-36174837

RESUMO

Mycobacterium tuberculosis uracil-DNA glycosylase (MtUng), a key DNA repair enzyme, represents an attractive target for the design of new antimycobacterial agents. However, only a limited number of weak MtUng inhibitors are reported, primarily based on the uracil ring, and hence, lack diversity. We report the first structure-based virtual screening (SBVS) using three separate libraries consisting of uracil and non-uracil small molecules, together with the FDA-approved drugs. Twenty diverse virtual hits with the highest predicted binding were procured and screened using a fluorescence-based assay to evaluate their potential to inhibit MtUng. Several of these molecules were found to inhibit MtUng activity at low mM and µM levels, comparable to or better than several other reported Ung inhibitors. Thus, these molecules represent a diverse set of scaffolds for developing next-generation MtUng inhibitors. The most active uracil-based compound 5 (IC50 = 0.14 mM) was found to be âˆ¼ 15-fold more potent than the positive control, uracil. The binding stability and conformation of compound 5 in complex with the enzyme were further confirmed using molecular dynamics simulation.


Assuntos
Mycobacterium tuberculosis , Uracila-DNA Glicosidase , Uracila-DNA Glicosidase/química , Uracila-DNA Glicosidase/genética , Uracila-DNA Glicosidase/metabolismo , Simulação de Dinâmica Molecular , Uracila/farmacologia , Uracila/metabolismo , Antibacterianos
5.
Int J Mol Sci ; 23(7)2022 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-35409221

RESUMO

Glycogen synthase kinase 3 beta (GSK-3ß) is an evolutionarily conserved serine-threonine kinase dysregulated in numerous pathologies, such as Alzheimer's disease and cancer. Even though GSK-3ß is a validated pharmacological target most of its inhibitors have two main limitations: the lack of selectivity due to the high homology that characterizes the ATP binding site of most kinases, and the toxicity that emerges from GSK-3ß complete inhibition which translates into the impairment of the plethora of pathways GSK-3ß is involved in. Starting from a 1D 19F NMR fragment screening, we set up several biophysical assays for the identification of GSK-3ß inhibitors capable of binding protein hotspots other than the ATP binding pocket or to the ATP binding pocket, but with an affinity able of competing with a reference binder. A phosphorylation activity assay on a panel of several kinases provided selectivity data that were further rationalized and corroborated by structural information on GSK-3ß in complex with the hit compounds. In this study, we identified promising fragments, inhibitors of GSK-3ß, while proposing an alternative screening workflow that allows facing the flaws that characterize the most common GSK-3ß inhibitors through the identification of selective inhibitors and/or inhibitors able to modulate GSK-3ß activity without leading to its complete inhibition.


Assuntos
Doença de Alzheimer , Trifosfato de Adenosina/metabolismo , Doença de Alzheimer/metabolismo , Sítios de Ligação , Glicogênio Sintase Quinase 3 beta/metabolismo , Humanos , Fosforilação
6.
Plant J ; 98(5): 864-883, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30758092

RESUMO

Plant height (PH) and plant width (PW), two of the major plant architectural traits determining the yield and productivity of a crop, are defined by diverse morphometric characteristics of the shoot apical meristem (SAM). The identification of potential molecular tags from a single gene that simultaneously modulates these plant/SAM architectural traits is therefore prerequisite to achieve enhanced yield and productivity in crop plants, including chickpea. Large-scale multienvironment phenotyping of the association panel and mapping population have ascertained the efficacy of three vital SAM morphometric trait parameters, SAM width, SAM height and SAM area, as key indicators to unravel the genetic basis of the wide PW and PH trait variations observed in desi chickpea. This study integrated a genome-wide association study (GWAS); quantitative trait locus (QTL)/fine-mapping and map-based cloning with molecular haplotyping; transcript profiling; and protein-DNA interaction assays for the dissection of plant architectural traits in chickpea. These exertions delineated natural alleles and superior haplotypes from a CabHLH121 transcription factor (TF) gene within the major QTL governing PW, PH and SAM morphometric traits. A genome-wide protein-DNA interaction assay assured the direct binding of a known stem cell master regulator, CaWUS, to the WOX-homeodomain TF binding sites of a CabHLH121 gene and its constituted haplotypes. The differential expression of CaWUS and transcriptional regulation of its target CabHLH121 gene/haplotypes were apparent, suggesting their collective role in altering SAM morphometric characteristics and plant architectural traits in the contrasting near isogenic lines (NILs). The NILs introgressed with a superior haplotype of a CabHLH121 exhibited optimal PW and desirable PH as well as enhanced yield and productivity without compromising any component of agronomic performance. These molecular signatures of the CabHLH121 TF gene have the potential to regulate both PW and PH traits through the modulation of proliferation, differentiation and maintenance of the meristematic stem cell population in the SAM; therefore, these signatures will be useful in the translational genomic study of chickpea genetic enhancement. The restructured cultivars with desirable PH (semidwarf) and PW will ensure maximal planting density in a specified cultivable field area, thereby enhancing the overall yield and productivity of chickpea. This can essentially facilitate the achievement of better remunerative outputs by farmers with rational land use, therefore ensuring global food security in the present scenario of an increasing population density and shrinking per capita land area.


Assuntos
Biomassa , Cicer/genética , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas , Meristema/genética , Brotos de Planta/genética , Alelos , Mapeamento Cromossômico , Cicer/anatomia & histologia , Cicer/metabolismo , Genes de Plantas/genética , Genoma de Planta/genética , Genômica/métodos , Genótipo , Haplótipos , Meristema/anatomia & histologia , Meristema/metabolismo , Brotos de Planta/anatomia & histologia , Brotos de Planta/metabolismo , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas/genética
7.
Plant Physiol ; 180(1): 253-275, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30737266

RESUMO

The identification of functionally relevant molecular tags is vital for genomics-assisted crop improvement and enhancement of seed yield, quality, and productivity in chickpea (Cicer arietinum). The simultaneous improvement of yield/productivity as well as quality traits often requires pyramiding of multiple genes, which remains a major hurdle given various associated epistatic and pleotropic effects. Unfortunately, no single gene that can improve yield/productivity along with quality and other desirable agromorphological traits is known, hampering the genetic enhancement of chickpea. Using a combinatorial genomics-assisted breeding and functional genomics strategy, this study identified natural alleles and haplotypes of an ABCC3-type transporter gene that regulates seed weight, an important domestication trait, by transcriptional regulation and modulation of the transport of glutathione conjugates in seeds of desi and kabuli chickpea. The superior allele/haplotype of this gene introgressed in desi and kabuli near-isogenic lines enhances the seed weight, yield, productivity, and multiple desirable plant architecture and seed-quality traits without compromising agronomic performance. These salient findings can expedite crop improvement endeavors and the development of nutritionally enriched high-yielding cultivars in chickpea.


Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Cicer/genética , Glutationa/metabolismo , Proteínas de Plantas/genética , Sementes/crescimento & desenvolvimento , Transportadores de Cassetes de Ligação de ATP/metabolismo , Transporte Biológico , Mapeamento Cromossômico , Cicer/metabolismo , Regulação da Expressão Gênica de Plantas , Genoma de Planta , Estudo de Associação Genômica Ampla , Haplótipos , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Melhoramento Vegetal , Proteínas de Plantas/metabolismo , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas , Locos de Características Quantitativas , Sementes/genética
9.
Funct Integr Genomics ; 19(6): 973-992, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31177403

RESUMO

Developing functional molecular tags from the cis-regulatory sequence components of genes is vital for their deployment in efficient genetic dissection of complex quantitative traits in crop plants including chickpea. The current study identified 431,194 conserved non-coding SNP (CNSNP) from the cis-regulatory element regions of genes which were annotated on a chickpea genome. These genome-wide CNSNP marker resources are made publicly accessible through a user-friendly web-database ( http://www.cnsnpcicarbase.com ). The CNSNP-based quantitative trait loci (QTL) and expression QTL (eQTL) mapping and genome-wide association study (GWAS) were further integrated with global gene expression landscapes, molecular haplotyping, and DNA-protein interaction study in the association panel and recombinant inbred lines (RIL) mapping population to decode complex genetic architecture of one of the vital seed yield trait under drought stress, drought yield index (DYI), in chickpea. This delineated two constituted natural haplotypes and alleles from a histone H3 protein-coding gene and its transcriptional regulator NAC transcription factor (TF) harboring the major QTLs and trans-acting eQTL governing DYI in chickpea. The effect of CNSNPs in TF-binding cis-element of a histone H3 gene in altering the binding affinity and transcriptional activity of NAC TF based on chromatin immunoprecipitation-quantitative PCR (ChIP-qPCR) assay was evident. The CNSNP-led promising molecular tags scanned will essentially have functional significance to decode transcriptional gene regulatory function and thus can drive translational genomic analysis in chickpea.


Assuntos
Cicer/genética , Produtos Agrícolas/genética , Locos de Características Quantitativas , Sequências Reguladoras de Ácido Nucleico , Estresse Fisiológico , Cicer/crescimento & desenvolvimento , Cicer/metabolismo , Produtos Agrícolas/crescimento & desenvolvimento , Produtos Agrícolas/metabolismo , Secas , Histonas/genética , Histonas/metabolismo , Melhoramento Vegetal/métodos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Característica Quantitativa Herdável , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transcriptoma
10.
Plant Cell Environ ; 42(1): 158-173, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29676051

RESUMO

Understanding the genetic basis of photosynthetic efficiency (PE) contributing to enhanced seed yield per plant (SYP) is vital for genomics-assisted crop improvement of chickpea. The current study employed an integrated genomic strategy involving photosynthesis pathway gene-based association mapping, genome-wide association study, quantitative trait loci (QTL) mapping, and expression profiling. This identified 16 potential single nucleotide polymorphism loci linked to major QTLs underlying 16 candidate genes significantly associated with PE and SYP traits in chickpea. The allelic variants were tightly linked to positively interacting QTLs regulating both enhanced PE and SYP traits as exemplified by a chlorophyll A-B binding protein-coding gene. The leaf tissue-specific pronounced up-regulated expression of 16 associated genes in germplasm accessions and homozygous individuals of mapping population was evident. Such combinatorial genomic strategy coupled with gene haplotype-specific association and in silico protein-protein interaction study delineated natural alleles and superior haplotypes from a chlorophyll A-B binding (CAB) protein-coding gene and its interacting gene, Timing of CAB Expression 1 (TOC1), which appear to be most promising candidates in modulating chickpea PE and SYP traits. These functionally pertinent molecular signatures identified have efficacy to drive marker-assisted selection for developing PE-enriched cultivars with high seed yield in chickpea.


Assuntos
Cicer/genética , Fotossíntese/genética , Característica Quantitativa Herdável , Sementes/genética , Mapeamento Cromossômico , Cicer/crescimento & desenvolvimento , Cicer/fisiologia , Produção Agrícola/métodos , Perfilação da Expressão Gênica , Genes de Plantas/genética , Polimorfismo de Nucleotídeo Único/genética , Locos de Características Quantitativas/genética , Sementes/crescimento & desenvolvimento
11.
Theor Appl Genet ; 132(7): 2017-2038, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30929032

RESUMO

KEY MESSAGE: A combinatorial genomic strategy delineated functionally relevant natural allele of a CLAVATA gene and its marker (haplotype)-assisted introgression led to development of the early-flowering chickpea cultivars with high flower number and enhanced yield/productivity. Unraveling the genetic components involved in CLAVATA (CLV) signaling is crucial for modulating important shoot apical meristem (SAM) characteristics and ultimately regulating diverse SAM-regulated agromorphological traits in crop plants. A genome-wide scan identified 142 CLV1-, 28 CLV2- and 6 CLV3-like genes, and their comprehensive genomic constitution and phylogenetic relationships were deciphered in chickpea. The QTL/fine mapping and map-based cloning integrated with high-resolution association analysis identified SNP loci from CaCLV3_01 gene within a major CaqDTF1.1/CaqFN1.1 QTL associated with DTF (days to 50% flowering) and FN (flower number) traits in chickpea, which was further ascertained by quantitative expression profiling. Molecular haplotyping of CaCLV3_01 gene, expressed specifically in SAM, constituted two major haplotypes that differentiated the early-DTF and high-FN chickpea accessions from late-DTF and low-FN. Enhanced accumulation of transcripts of superior CaCLV3_01 gene haplotype and known flowering promoting genes was observed in the corresponding haplotype-introgressed early-DTF and high-FN near-isogenic lines (NILs) with narrow SAM width. The superior haplotype-introgressed NILs exhibited early-flowering, high-FN and enhanced seed yield/productivity without compromising agronomic performance. These delineated molecular signatures can regulate DTF and FN traits through SAM proliferation and differentiation and thereby will be useful for translational genomic study to develop early-flowering cultivars with enhanced yield/productivity.


Assuntos
Cicer/genética , Flores/fisiologia , Transdução de Sinais , Mapeamento Cromossômico , Cicer/fisiologia , Genoma de Planta , Haplótipos , Proteínas de Membrana/genética , Fenótipo , Filogenia , Proteínas de Plantas/genética , Locos de Características Quantitativas
12.
BMC Bioinformatics ; 18(1): 325, 2017 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-28676075

RESUMO

BACKGROUND: sgnesR (Stochastic Gene Network Expression Simulator in R) is an R package that provides an interface to simulate gene expression data from a given gene network using the stochastic simulation algorithm (SSA). The package allows various options for delay parameters and can easily included in reactions for promoter delay, RNA delay and Protein delay. A user can tune these parameters to model various types of reactions within a cell. As examples, we present two network models to generate expression profiles. We also demonstrated the inference of networks and the evaluation of association measure of edge and non-edge components from the generated expression profiles. RESULTS: The purpose of sgnesR is to enable an easy to use and a quick implementation for generating realistic gene expression data from biologically relevant networks that can be user selected. CONCLUSIONS: sgnesR is freely available for academic use. The R package has been tested for R 3.2.0 under Linux, Windows and Mac OS X.


Assuntos
Redes Reguladoras de Genes , Interface Usuário-Computador , Algoritmos , Expressão Gênica , Internet
13.
Funct Integr Genomics ; 17(6): 711-723, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28600722

RESUMO

A combinatorial genomics-assisted breeding strategy encompassing association analysis, genetic mapping and expression profiling is found most promising for quantitative dissection of complex traits in crop plants. The present study employed GWAS (genome-wide association study) using 24,405 SNPs (single nucleotide polymorphisms) obtained with genotyping-by-sequencing (GBS) of 92 sequenced desi and kabuli accessions of chickpea. This identified eight significant genomic loci associated with erect (E)/semi-erect (SE) vs. spreading (S)/semi-spreading (SS)/prostrate (P) plant growth habit (PGH) trait differentiation regardless of diverse desi and kabuli genetic backgrounds of chickpea. These associated SNPs in combination explained 23.8% phenotypic variation for PGH in chickpea. Five PGH-associated genes were validated successfully in E/SE and SS/S/P PGH-bearing parental accessions and homozygous individuals of three intra- and interspecific RIL (recombinant inbred line) mapping populations as well as 12 contrasting desi and kabuli chickpea germplasm accessions by selective genotyping through Sequenom MassARRAY. The shoot apical, inflorescence and floral meristems-specific expression, including upregulation (seven-fold) of five PGH-associated genes especially in germplasm accessions and homozygous RIL mapping individuals contrasting with E/SE PGH traits was apparent. Collectively, this integrated genomic strategy delineated diverse non-synonymous SNPs from five candidate genes with strong allelic effects on PGH trait variation in chickpea. Of these, two vernalization-responsive non-synonymous SNP alleles carrying SNF2 protein-coding gene and B3 transcription factor associated with PGH traits were found to be the most promising in chickpea. The SNP allelic variants associated with E/SE/SS/S PGH trait differentiation were exclusively present in all cultivated desi and kabuli chickpea accessions while wild species/accessions belonging to primary, secondary and tertiary gene pools mostly contained prostrate PGH-associated SNP alleles. This indicates strong adaptive natural/artificial selection pressure (Tajima's D 3.15 to 4.57) on PGH-associated target genomic loci during chickpea domestication. These vital leads thus have potential to decipher complex transcriptional regulatory gene function of PGH trait differentiation and for understanding the selective sweep-based PGH trait evolution and domestication pattern in cultivated and wild chickpea accessions adapted to diverse agroclimatic conditions. Collectively, the essential inputs generated will be of profound use in marker-assisted genetic enhancement to develop cultivars with desirable plant architecture of erect growth habit types in chickpea.


Assuntos
Cicer/genética , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Cicer/crescimento & desenvolvimento , Genoma de Planta , Estudo de Associação Genômica Ampla , Fenótipo
14.
Bioinformatics ; 32(21): 3345-3347, 2016 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-27402900

RESUMO

MOTIVATION: Data from RNA-seq experiments provide us with many new possibilities to gain insights into biological and disease mechanisms of cellular functioning. However, the reproducibility and robustness of RNA-seq data analysis results is often unclear. This is in part attributed to the two counter acting goals of (i) a cost efficient and (ii) an optimal experimental design leading to a compromise, e.g. in the sequencing depth of experiments. RESULTS: We introduce an R package called samExploreR that allows the subsampling (m out of n bootstraping) of short-reads based on SAM files facilitating the investigation of sequencing depth related questions for the experimental design. Overall, this provides a systematic way for exploring the reproducibility and robustness of general RNA-seq studies. We exemplify the usage of samExploreR by studying the influence of the sequencing depth and the annotation on the identification of differentially expressed genes. AVAILABILITY AND IMPLEMENTATION: samExploreR is available as an R package from Bioconductor. CONTACT: v@bio-complexity.comSupplementary information: Supplementary data are available at Bioinformatics online.


Assuntos
RNA/genética , Análise de Sequência de RNA , Reprodutibilidade dos Testes , Projetos de Pesquisa , Software
15.
Nucleic Acids Res ; 43(3): 1937-44, 2015 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-25628357

RESUMO

DNA has proved to be an excellent material for nanoscale construction because complementary DNA duplexes are programmable and structurally predictable. However, in the absence of Watson-Crick pairings, DNA can be structurally more diverse. Here, we describe the crystal structures of d(ACTCGGATGAT) and the brominated derivative, d(AC(Br)UCGGA(Br)UGAT). These oligonucleotides form parallel-stranded duplexes with a crystallographically equivalent strand, resulting in the first examples of DNA crystal structures that contains four different symmetric homo base pairs. Two of the parallel-stranded duplexes are coaxially stacked in opposite directions and locked together to form a tetraplex through intercalation of the 5'-most A-A base pairs between adjacent G-G pairs in the partner duplex. The intercalation region is a new type of DNA tertiary structural motif with similarities to the i-motif. (1)H-(1)H nuclear magnetic resonance and native gel electrophoresis confirmed the formation of a parallel-stranded duplex in solution. Finally, we modified specific nucleotide positions and added d(GAY) motifs to oligonucleotides and were readily able to obtain similar crystals. This suggests that this parallel-stranded DNA structure may be useful in the rational design of DNA crystals and nanostructures.


Assuntos
DNA/química , Substâncias Intercalantes/química , Conformação de Ácido Nucleico , Halogênios/química , Espectroscopia de Ressonância Magnética
16.
BMC Bioinformatics ; 17: 129, 2016 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-26987731

RESUMO

BACKGROUND: It is generally acknowledged that a functional understanding of a biological system can only be obtained by an understanding of the collective of molecular interactions in form of biological networks. Protein networks are one particular network type of special importance, because proteins form the functional base units of every biological cell. On a mesoscopic level of protein networks, modules are of significant importance because these building blocks may be the next elementary functional level above individual proteins allowing to gain insight into fundamental organizational principles of biological cells. RESULTS: In this paper, we provide a comparative analysis of five popular and four novel module detection algorithms. We study these module prediction methods for simulated benchmark networks as well as 10 biological protein interaction networks (PINs). A particular focus of our analysis is placed on the biological meaning of the predicted modules by utilizing the Gene Ontology (GO) database as gold standard for the definition of biological processes. Furthermore, we investigate the robustness of the results by perturbing the PINs simulating in this way our incomplete knowledge of protein networks. CONCLUSIONS: Overall, our study reveals that there is a large heterogeneity among the different module prediction algorithms if one zooms-in the biological level of biological processes in the form of GO terms and all methods are severely affected by a slight perturbation of the networks. However, we also find pathways that are enriched in multiple modules, which could provide important information about the hierarchical organization of the system.


Assuntos
Algoritmos , Ontologia Genética , Mapeamento de Interação de Proteínas , Animais , Análise por Conglomerados , Eucariotos/metabolismo , Humanos
17.
Chembiochem ; 17(12): 1177-83, 2016 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-26629965

RESUMO

DNA can adopt many other structures beyond the canonical B-form double helix. These alternative DNA structures have become increasingly significant as new biological roles are found for them. Additionally, there has been a growing interest in using non-canonical base pairs to provide structural diversity for designing DNA architectures for nanotechnology applications. We recently described the crystal structure of d(ACTCGGATGAT), which forms a tetraplex through parallel-stranded homo-base pairs and nucleobase intercalation. The homoduplex region contains a d(YGA⋅YGA) motif observed in crystal and solution structures. Here, we examine the structural implications of the homopyrimidine base pair within this motif. We determined crystal structures of two variants that differ from the original structure in the homopyrimidine base pairs and number of d(YGA) motifs. Our results show that the intercalation-locked tetraplex motif is predictable in these different sequence contexts and that substituting C⋅C base pairs for T⋅T base pairs introduces asymmetry to the homoduplex. These results have important implications for utilizing d(YGA) motifs in DNA crystal design and could provide a basis for understanding how local structures could be associated with repeat expansions.


Assuntos
Oligonucleotídeos/química , Pirimidinas/química , Pareamento de Bases , Cristalografia por Raios X , Citosina/química , Substâncias Intercalantes/química , Conformação de Ácido Nucleico , Motivos de Nucleotídeos , Oligonucleotídeos/síntese química
18.
Plant Mol Biol ; 89(4-5): 403-20, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26394865

RESUMO

A combinatorial approach of candidate gene-based association analysis and genome-wide association study (GWAS) integrated with QTL mapping, differential gene expression profiling and molecular haplotyping was deployed in the present study for quantitative dissection of complex flowering time trait in chickpea. Candidate gene-based association mapping in a flowering time association panel (92 diverse desi and kabuli accessions) was performed by employing the genotyping information of 5724 SNPs discovered from 82 known flowering chickpea gene orthologs of Arabidopsis and legumes as well as 832 gene-encoding transcripts that are differentially expressed during flower development in chickpea. GWAS using both genome-wide GBS- and candidate gene-based genotyping data of 30,129 SNPs in a structured population of 92 sequenced accessions (with 200-250 kb LD decay) detected eight maximum effect genomic SNP loci (genes) associated (34% combined PVE) with flowering time. Six flowering time-associated major genomic loci harbouring five robust QTLs mapped on a high-resolution intra-specific genetic linkage map were validated (11.6-27.3% PVE at 5.4-11.7 LOD) further by traditional QTL mapping. The flower-specific expression, including differential up- and down-regulation (>three folds) of eight flowering time-associated genes (including six genes validated by QTL mapping) especially in early flowering than late flowering contrasting chickpea accessions/mapping individuals during flower development was evident. The gene haplotype-based LD mapping discovered diverse novel natural allelic variants and haplotypes in eight genes with high trait association potential (41% combined PVE) for flowering time differentiation in cultivated and wild chickpea. Taken together, eight potential known/candidate flowering time-regulating genes [efl1 (early flowering 1), FLD (Flowering locus D), GI (GIGANTEA), Myb (Myeloblastosis), SFH3 (SEC14-like 3), bZIP (basic-leucine zipper), bHLH (basic helix-loop-helix) and SBP (SQUAMOSA promoter binding protein)], including novel markers, QTLs, alleles and haplotypes delineated by aforesaid genome-wide integrated approach have potential for marker-assisted genetic improvement and unravelling the domestication pattern of flowering time in chickpea.


Assuntos
Cicer/crescimento & desenvolvimento , Cicer/genética , Genoma de Planta , Mapeamento Cromossômico , Flores/genética , Flores/crescimento & desenvolvimento , Perfilação da Expressão Gênica , Estudo de Associação Genômica Ampla , Genótipo , Haplótipos , Desequilíbrio de Ligação , Fenótipo , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Fatores de Tempo
19.
Bioinformatics ; 30(19): 2834-6, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24928209

RESUMO

SUMMARY: NetBioV (Network Biology Visualization) is an R package that allows the visualization of large network data in biology and medicine. The purpose of NetBioV is to enable an organized and reproducible visualization of networks by emphasizing or highlighting specific structural properties that are of biological relevance. AVAILABILITY AND IMPLEMENTATION: NetBioV is freely available for academic use. The package has been tested for R 2.14.2 under Linux, Windows and Mac OS X. It is available from Bioconductor.


Assuntos
Biologia Computacional/métodos , Redes Reguladoras de Genes , Software , Algoritmos , Arabidopsis/metabolismo , Gráficos por Computador , Humanos , Linfoma de Células B/metabolismo , Linguagens de Programação , Reprodutibilidade dos Testes
20.
J Exp Bot ; 66(5): 1271-90, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25504138

RESUMO

Phylogenetic footprinting identified 666 genome-wide paralogous and orthologous CNMS (conserved non-coding microsatellite) markers from 5'-untranslated and regulatory regions (URRs) of 603 protein-coding chickpea genes. The (CT)n and (GA)n CNMS carrying CTRMCAMV35S and GAGA8BKN3 regulatory elements, respectively, are abundant in the chickpea genome. The mapped genic CNMS markers with robust amplification efficiencies (94.7%) detected higher intraspecific polymorphic potential (37.6%) among genotypes, implying their immense utility in chickpea breeding and genetic analyses. Seventeen differentially expressed CNMS marker-associated genes showing strong preferential and seed tissue/developmental stage-specific expression in contrasting genotypes were selected to narrow down the gene targets underlying seed weight quantitative trait loci (QTLs)/eQTLs (expression QTLs) through integrative genetical genomics. The integration of transcript profiling with seed weight QTL/eQTL mapping, molecular haplotyping, and association analyses identified potential molecular tags (GAGA8BKN3 and RAV1AAT regulatory elements and alleles/haplotypes) in the LOB-domain-containing protein- and KANADI protein-encoding transcription factor genes controlling the cis-regulated expression for seed weight in the chickpea. This emphasizes the potential of CNMS marker-based integrative genetical genomics for the quantitative genetic dissection of complex seed weight in chickpea.


Assuntos
Cicer/genética , Genoma de Planta , Repetições de Microssatélites , Alelos , Sequência de Bases , Cicer/química , Cicer/classificação , Sequência Conservada , Marcadores Genéticos , Genômica , Genótipo , Dados de Sequência Molecular , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/genética , Locos de Características Quantitativas , Sementes/química , Sementes/classificação , Sementes/genética , Alinhamento de Sequência
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