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1.
Laryngorhinootologie ; 101(8): 638-645, 2022 08.
Artigo em Alemão | MEDLINE | ID: mdl-35468645

RESUMO

Injuries of the auricle can range from simple lacerations to complete avulsions. Many techniques of ear replantation have been described in the literature in addition to the type and extent of the involved auricular structures. A direct reattachment of the amputated pinna without microsurgery is rarely successful due to necrosis of the avulsed fragment. Whereas, reconstructions with pocket methods and their variations might lead to better results. In this article we would like to discuss some of these approaches and demonstrate a two-stage reconstruction technique for subtotal avulsion of the auricle.


Assuntos
Amputação Traumática , Pavilhão Auricular , Amputação Traumática/cirurgia , Pavilhão Auricular/cirurgia , Orelha Externa/cirurgia , Humanos , Microcirurgia , Reimplante/métodos
2.
Plant Physiol ; 170(3): 1595-610, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26773008

RESUMO

Gene duplications are an important factor in plant evolution, and lineage-specific expanded (LSE) genes are of particular interest. Receptor-like kinases expanded massively in land plants, and leucine-rich repeat receptor-like kinases (LRR-RLK) constitute the largest receptor-like kinases family. Based on the phylogeny of 7,554 LRR-RLK genes from 31 fully sequenced flowering plant genomes, the complex evolutionary dynamics of this family was characterized in depth. We studied the involvement of selection during the expansion of this family among angiosperms. LRR-RLK subgroups harbor extremely contrasting rates of duplication, retention, or loss, and LSE copies are predominantly found in subgroups involved in environmental interactions. Expansion rates also differ significantly depending on the time when rounds of expansion or loss occurred on the angiosperm phylogenetic tree. Finally, using a dN/dS-based test in a phylogenetic framework, we searched for selection footprints on LSE and single-copy LRR-RLK genes. Selective constraint appeared to be globally relaxed at LSE genes, and codons under positive selection were detected in 50% of them. Moreover, the leucine-rich repeat domains, and specifically four amino acids in them, were found to be the main targets of positive selection. Here, we provide an extensive overview of the expansion and evolution of this very large gene family.


Assuntos
Evolução Molecular , Magnoliopsida/genética , Família Multigênica , Proteínas de Plantas/genética , Receptores Proteína Tirosina Quinases/genética , Sequências Repetitivas de Aminoácidos , Motivos de Aminoácidos , Duplicação Gênica , Variação Genética , Magnoliopsida/classificação , Modelos Genéticos , Filogenia , Proteínas de Plantas/classificação , Receptores Proteína Tirosina Quinases/classificação , Seleção Genética , Especificidade da Espécie , Fatores de Tempo
3.
BMC Plant Biol ; 14: 151, 2014 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-24884640

RESUMO

BACKGROUND: Recurrent gene duplication and retention played an important role in angiosperm genome evolution. It has been hypothesized that these processes contribute significantly to plant adaptation but so far this hypothesis has not been tested at the genome scale. RESULTS: We studied available sequenced angiosperm genomes to assess the frequency of positive selection footprints in lineage specific expanded (LSE) gene families compared to single-copy genes using a dN/dS-based test in a phylogenetic framework. We found 5.38% of alignments in LSE genes with codons under positive selection. In contrast, we found no evidence for codons under positive selection in the single-copy reference set. An analysis at the branch level shows that purifying selection acted more strongly on single-copy genes than on LSE gene clusters. Moreover we detect significantly more branches indicating evolution under positive selection and/or relaxed constraint in LSE genes than in single-copy genes. CONCLUSIONS: In this - to our knowledge -first genome-scale study we provide strong empirical support for the hypothesis that LSE genes fuel adaptation in angiosperms. Our conservative approach for detecting selection footprints as well as our results can be of interest for further studies on (plant) gene family evolution.


Assuntos
Adaptação Fisiológica/genética , Duplicação Gênica , Genoma de Planta , Análise por Conglomerados , Códon/genética , Bases de Dados Genéticas , Anotação de Sequência Molecular , Família Multigênica , Mutação/genética , Polimorfismo Genético , Seleção Genética , Fatores de Tempo
4.
Mol Biol Evol ; 29(12): 3641-52, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22787283

RESUMO

Abiotic stresses such as drought, extreme temperatures, and salinity have a strong impact on plant adaptation. They act as selective forces on plant physiology and morphology. These selective pressures leave characteristic footprints that can be detected at the DNA sequence level using population genetic tools. On the basis of a candidate gene approach, we investigated signatures of adaptation in two wild tomato species, Solanum peruvianum and S. chilense. These species are native to western South America and constitute a model system for studying adaptation, due to their ability to colonize diverse habitats and the available genetic resources. We have determined the selective forces acting on the C-repeat binding factor (CBF) gene family, which consists of three genes, and is known to be involved in tolerance to abiotic stresses, in particular in cold tolerance. We also analyzed the expression pattern of these genes after drought and cold stresses. We found that CBF3 evolves under very strong purifying selection, CBF2 is under balancing selection in some populations of both species (S. peruvianum/Quicacha and S. chilense/Nazca) maintaining a trans-species polymorphism, and CBF1 is a pseudogene. In contrast to previous studies of cultivated tomatoes showing that only CBF1 was cold induced, we found that all three CBF genes are cold induced in wild tomatoes. All three genes are also drought induced. CBF2 exhibits an allele-specific expression pattern associated with the trans-species polymorphism.


Assuntos
Adaptação Biológica/genética , Variação Genética , Genética Populacional , Proteínas de Plantas/genética , Solanum lycopersicum/genética , Fatores de Transcrição/genética , Chile , Temperatura Baixa , Secas , Conversão Gênica/genética , Perfilação da Expressão Gênica , Funções Verossimilhança , Solanum lycopersicum/crescimento & desenvolvimento , Modelos Genéticos , Peru , Especificidade da Espécie
5.
New Phytol ; 190(4): 1032-1044, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21323928

RESUMO

Wild tomato species are a valuable system in which to study local adaptation to drought: they grow in diverse environments ranging from mesic to extremely arid conditions. Here, we investigate the evolution of members of the Asr (ABA/water stress/ripening induced) gene family, which have been reported to be involved in the water stress response. We analysed molecular variation in the Asr gene family in populations of two closely related species, Solanum chilense and Solanum peruvianum. We concluded that Asr1 has evolved under strong purifying selection. In contrast to previous reports, we did not detect evidence for positive selection at Asr2. However, Asr4 shows patterns consistent with local adaptation in an S. chilense population that lives in an extremely dry environment. We also discovered a new member of the gene family, Asr5. Our results show that the Asr genes constitute a dynamic gene family and provide an excellent example of tandemly arrayed genes that are of importance in adaptation. Taking the potential distribution of the species into account, it appears that S. peruvianum can cope with a great variety of environmental conditions without undergoing local adaptation, whereas S. chilense undergoes local adaptation more frequently.


Assuntos
Adaptação Fisiológica , Secas , Evolução Molecular , Família Multigênica , Solanum/genética , Alelos , Ecossistema , Genes de Plantas , Mutação INDEL , Polimorfismo Genético , Seleção Genética , Análise de Sequência de DNA , Solanum/fisiologia
6.
Stem Cell Res ; 54: 102417, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34119956

RESUMO

MIRAGE syndrome is a multisystem disorder caused by mutations in SAMD9 (sterile α motif domain-containing protein 9) with a high mortality in the first decade of life. We generated 2 human induced pluripotent stem cell lines from male children diagnosed with MIRAGE syndrome. The cell lines were generated from fibroblasts by integration-free reprogramming using the Sendai virus. Both cell lines were fully characterized regarding their pluripotent identity and differentiation potential, and quality controlled for karyotypic integrity, cell line identity and clearance of reprogramming vectors. The generated cell lines represent a valuable tool to study the disease mechanism of MIRAGE syndrome.


Assuntos
Células-Tronco Pluripotentes Induzidas , Diferenciação Celular , Linhagem Celular , Reprogramação Celular , Criança , Fibroblastos , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Masculino , Vírus Sendai/genética
7.
Stem Cell Res ; 54: 102406, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34062331

RESUMO

Focal segmental glomerulosclerosis (FSGS) is a major cause of familial nephrotic syndrome. We generated 20 induced pluripotent stem cell lines from patients diagnosed with FSGS. The iPSC lines include 8 female and 12 male lines and cover a donor age range from 31 to 78. The lines were generated from peripheral blood mononuclear cells by integration-free reprogramming using Sendai virus vectors. Cell lines were fully characterized regarding their pluripotency and differentiation potential, and quality controlled for karyotypic integrity, identity and clearance of reprogramming vectors. The generated cell lines represent a valuable tool for disease modelling and drug development for FSGS.


Assuntos
Glomerulosclerose Segmentar e Focal , Células-Tronco Pluripotentes Induzidas , Linhagem Celular , Feminino , Glomerulosclerose Segmentar e Focal/genética , Humanos , Leucócitos Mononucleares , Masculino , Vírus Sendai/genética
8.
PeerJ ; 9: e11192, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33986985

RESUMO

BACKGROUND: Dragonflies and damselflies (Odonata) are important components in biomonitoring due to their amphibiotic lifecycle and specific habitat requirements. They are charismatic and popular insects, but can be challenging to identify despite large size and often distinct coloration, especially the immature stages. DNA-based assessment tools rely on validated DNA barcode reference libraries evaluated in a supraregional context to minimize taxonomic incongruence and identification mismatches. METHODS: This study reports on findings from the analysis of the most comprehensive DNA barcode dataset for Central European Odonata to date, with 103 out of 145 recorded European species included and publicly deposited in the Barcode of Life Data System (BOLD). The complete dataset includes 697 specimens (548 adults, 108 larvae) from 274 localities in 16 countries with a geographic emphasis on Central Europe. We used BOLD to generate sequence divergence metrics and to examine the taxonomic composition of the DNA barcode clusters within the dataset and in comparison with all data on BOLD. RESULTS: Over 88% of the species included can be readily identified using their DNA barcodes and the reference dataset provided. Considering the complete European dataset, unambiguous identification is hampered in 12 species due to weak mitochondrial differentiation and partial haplotype sharing. However, considering the known species distributions only two groups of five species possibly co-occur, leading to an unambiguous identification of more than 95% of the analysed Odonata via DNA barcoding in real applications. The cases of small interspecific genetic distances and the observed deep intraspecific variation in Cordulia aenea (Linnaeus, 1758) are discussed in detail and the corresponding taxa in the public reference database are highlighted. They should be considered in future applications of DNA barcoding and metabarcoding and represent interesting evolutionary biological questions, which call for in depth analyses of the involved taxa throughout their distribution ranges.

9.
Acta Trop ; 212: 105654, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32783956

RESUMO

Alveolar echinococcosis (AE) is a rare zoonotic disease caused by the larval stage of Echinococcus multilocularis. Despite its low world-wide prevalence, this disease shows differences in the regional distribution of cases. In the present cohort study, we analyse the distribution of AE according to environmental and geographical factors in Germany. We identified the place of residence of 591 cases of AE from the national database for AE, and georeferenced these localities in the Universal Transverse Mercator coordinate system. Data on elevation, air temperature, precipitation height and land cover were mapped out and correlated with the distribution of cases of disease during the period 1992-2018. Moran's I statistic was used for spatial autocorrelation. Differences in frequency distribution between elevation, air temperature, precipitation height and landscape feature classes were analysed with the Kruskal-Wallis test. With the multiple linear regression analysis, we determined the influences and interactions of geographical and climatic factors on the number of AE cases. The results showed a heterogeneous distribution of AE cases with a higher concentration in southern Germany than in the rest of Germany (I = 0.225517, Z = 35.8182 and p < 0.001). There was a statistically significant difference in frequency distribution between precipitation height, air temperature, elevation and landscape feature classes and AE cases in Germany (p < 0.0001). In regions with higher elevations (505-672 m), moderate average air temperatures (6.0-7.9°C) and higher precipitation rates (701-1000 mm) most AE cases were recorded. It seems, that regions with higher precipitation rates, higher elevations and moderate average air temperatures have a higher infection burden and infection conditions. It is therefore extremely important to generate greater awareness of the disease in these regions, with the aim of recognising potential cases of AE as early as possible and introducing the appropriate therapeutic measures.


Assuntos
Equinococose/epidemiologia , Animais , Estudos de Coortes , Equinococose/etiologia , Meio Ambiente , Geografia , Alemanha/epidemiologia , Humanos , Temperatura , Fatores de Tempo
10.
Curr Protoc Stem Cell Biol ; 55(1): e123, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32956572

RESUMO

Advances in human pluripotent stem cell (hPSC) techniques have led them to become a widely used and powerful tool for a vast array of applications, including disease modeling, developmental studies, drug discovery and testing, and emerging cell-based therapies. hPSC workflows that require clonal expansion from single cells, such as CRISPR/Cas9-mediated genome editing, face major challenges in terms of efficiency, cost, and precision. Classical sub-cloning approaches depend on limiting dilution and manual colony picking, which are both time-consuming and labor-intensive, and lack a real proof of clonality. Here we describe the application of three different automated cell isolation and dispensing devices that can enhance the single-cell cloning process for hPSCs. In combination with optimized cell culture conditions, these devices offer an attractive alternative compared to manual methods. We explore various aspects of each device system and define protocols for their practical application. Following the workflow described here, single cell-derived hPSC sub-clones from each system maintain pluripotency and genetic stability. Furthermore, the workflows can be applied to uncover karyotypic mosaicism prevalent in bulk hPSC cultures. Our robust automated workflow facilitates high-throughput hPSC clonal selection and expansion, urgently needed in the operational pipelines of hPSC applications. © 2020 The Authors. Basic Protocol: Efficient automated hPSC single cell seeding and clonal expansion using the iotaSciences IsoCell platform Alternate Protocol 1: hPSC single cell seeding and clonal expansion using the Cellenion CellenONE single-cell dispenser Alternate Protocol 2: hPSC single cell seeding and clonal expansion using the Cytena single-cell dispenser Support Protocol 1: Coating cell culture plates with Geltrex Support Protocol 2: hPSC maintenance in defined feeder-free conditions Support Protocol 3: hPSC passaging in clumps Support Protocol 4: Laminin 521 coating of IsoCell plates and 96-well/384-well plates Support Protocol 5: Preparation of medium containing anti-apoptotic small molecules Support Protocol 6: 96- and 384-well target plate preparation prior to single cell seeding Support Protocol 7: Single cell dissociation of hPSCs Support Protocol 8: IsoCell-, CellenONE-, and Cytena-derived hPSC clone subculture and expansion.


Assuntos
Separação Celular/métodos , Clonagem Molecular/métodos , Células-Tronco Pluripotentes/citologia , Análise de Célula Única/métodos , Automação Laboratorial , Técnicas de Cultura de Células , Células Clonais , Edição de Genes , Humanos
11.
Nat Commun ; 11(1): 6336, 2020 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-33303764

RESUMO

The human proteome is a crucial intermediate between complex diseases and their genetic and environmental components, and an important source of drug development targets and biomarkers. Here, we comprehensively assess the genetic architecture of 257 circulating protein biomarkers of cardiometabolic relevance through high-depth (22.5×) whole-genome sequencing (WGS) in 1328 individuals. We discover 131 independent sequence variant associations (P < 7.45 × 10-11) across the allele frequency spectrum, all of which replicate in an independent cohort (n = 1605, 18.4x WGS). We identify for the first time replicating evidence for rare-variant cis-acting protein quantitative trait loci for five genes, involving both coding and noncoding variation. We construct and validate polygenic scores that explain up to 45% of protein level variation. We find causal links between protein levels and disease risk, identifying high-value biomarkers and drug development targets.


Assuntos
Miocárdio/metabolismo , Proteoma/genética , Sequenciamento Completo do Genoma , Regulação da Expressão Gênica , Redes Reguladoras de Genes , Predisposição Genética para Doença , Humanos , Herança Multifatorial/genética , Proteoma/metabolismo , Locos de Características Quantitativas/genética , Fatores de Risco
12.
Nat Genet ; 52(9): 950-957, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32719517

RESUMO

The diversity of maize (Zea mays) is the backbone of modern heterotic patterns and hybrid breeding. Historically, US farmers exploited this variability to establish today's highly productive Corn Belt inbred lines from blends of dent and flint germplasm pools. Here, we report de novo genome sequences of four European flint lines assembled to pseudomolecules with scaffold N50 ranging from 6.1 to 10.4 Mb. Comparative analyses with two US Corn Belt lines explains the pronounced differences between both germplasms. While overall syntenic order and consolidated gene annotations reveal only moderate pangenomic differences, whole-genome alignments delineating the core and dispensable genome, and the analysis of heterochromatic knobs and orthologous long terminal repeat retrotransposons unveil the dynamics of the maize genome. The high-quality genome sequences of the flint pool complement the maize pangenome and provide an important tool to study maize improvement at a genome scale and to enhance modern hybrid breeding.


Assuntos
Variação Genética/genética , Genoma de Planta/genética , Zea mays/genética , Cruzamento/métodos , Mapeamento Cromossômico , Genótipo , Vigor Híbrido/genética , Fenótipo
13.
Biomaterials ; 216: 119283, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31247481

RESUMO

Extracellular matrix (ECM) provides a scaffold for cells and tissues, but also supports organogenesis and tissue remodeling. The required instructive properties of the ECM to interact with cells depend on matrix architecture, structural proteins and functional matrix components such as growth factors, providing spatial, chemical and functional cues. Decellularized ECM (dECM) has been proposed as an instructive material that promotes tissue regeneration. We investigated the instructive ECM elements preserved in dECM and necessary to promote endothelial differentiation of human induced pluripotent stem cells (hiPSC). We show that detergent-decellularized human kidney ECM remains structurally intact and carries a number of heparin-binding growth factors, including FGF2, VEGF, BMP2, HGF, EGF, PDGF-BB and TGFß, albeit at reduced levels compared to native tissues. Clearance of these heparin-binding factors, or heparan-sulfate proteoclycans from ECM resulted in massively reduced differentiation of hiPSC, suggesting that remaining structural dECM proteins such as laminin, collagen or fibronectin alone are not instructive. In contrast, replenishing dECM with VEGF replaced medium-supplemented VEGF and resulted in more efficient differentiation of hiPSC into endothelial cells, and even in the absence of other culture-supplemented differentiation factors dECM alone was superior to geltrex. In conclusion, conditioning of dECM with specific growth factors acting as functional cues may allow to generate functional niches by selective promotion of cell attachment, survival and differentiation.


Assuntos
Células Endoteliais/citologia , Matriz Extracelular/química , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Alicerces Teciduais/química , Fator A de Crescimento do Endotélio Vascular/farmacologia , Materiais Biocompatíveis/química , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Fator A de Crescimento do Endotélio Vascular/química
14.
Sci Adv ; 4(8): eaar8602, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30128352

RESUMO

Wheat is an important staple grain for humankind globally because of its end-use quality and nutritional properties and its adaptability to diverse climates. For a small proportion of the population, specific wheat proteins can trigger adverse immune responses and clinical manifestations such as celiac disease, wheat allergy, baker's asthma, and wheat-dependent exercise-induced anaphylaxis (WDEIA). Establishing the content and distribution of the immunostimulatory regions in wheat has been hampered by the complexity of the wheat genome and the lack of complete genome sequence information. We provide novel insights into the wheat grain proteins based on a comprehensive analysis and annotation of the wheat prolamin Pfam clan grain proteins and other non-prolamin allergens implicated in these disorders using the new International Wheat Genome Sequencing Consortium bread wheat reference genome sequence, RefSeq v1.0. Celiac disease and WDEIA genes are primarily expressed in the starchy endosperm and show wide variation in protein- and transcript-level expression in response to temperature stress. Nonspecific lipid transfer proteins and α-amylase trypsin inhibitor gene families, implicated in baker's asthma, are primarily expressed in the aleurone layer and transfer cells of grains and are more sensitive to cold temperature. The study establishes a new reference map for immunostimulatory wheat proteins and provides a fresh basis for selecting wheat lines and developing diagnostics for products with more favorable consumer attributes.


Assuntos
Alérgenos/imunologia , Mapeamento Cromossômico/métodos , Proteínas de Plantas/genética , Proteínas de Plantas/imunologia , Sementes/imunologia , Triticum/genética , Hipersensibilidade a Trigo/imunologia , Alérgenos/genética , Asma/epidemiologia , Asma/genética , Asma/imunologia , Doença Celíaca/epidemiologia , Doença Celíaca/genética , Doença Celíaca/imunologia , Regulação da Expressão Gênica de Plantas , Humanos , Filogenia , Triticum/crescimento & desenvolvimento , Triticum/imunologia , Hipersensibilidade a Trigo/genética
16.
Biomed Mater ; 12(4): 045005, 2017 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-28396578

RESUMO

Native extracellular matrix (ECM) provides scaffolds for tissue engineering with natural architecture and biochemical composition. Maintaining the native ECM in decellularized tissues provides cues for cells, which promote their tissue specific arrangement and function. Several approaches have been used to decellularize ECM from the kidney in order to reestablish renal tissue but their comparability is hampered because methods for decellularization and assessment of ECM vary widely. Therefore, we applied a standardized immersion protocol to decellularize porcine kidney tissue with three detergents Triton X-100, SDS and sodium deoxycholate (SDC) at variable temperatures. For comparative analysis decellularization efficacies, structural preservation, composition and cell attachment and viability were analyzed. Structural ECM-conservation is strongly dependent on decellularization temperature, while preservation of glycosaminoglycans (GAG), collagens and cytokines was affected by the detergents used. GAG and collagens were best maintained by 1% SDS at 4 °C, whereas cytokines were best maintained in 1% SDC at 4 °C. Viability and attachment of human induced pluripotent stem cell derived renal precursor cells were best in SDC-ECM and thus not associated with the degree of GAG and collagen maintenance but the cytokine preservation. Based on structural and functional characteristics, we developed a scoring system that allows intra- and inter-study comparison of decellularization strategies. Application of the scoring system to our experimental data showed that decellularization with 1% SDS at 4 °C provided the highest structural and composition scores, while 1% SDC at 4 °C had lower structural and composition but a significantly better cell performance score. Inclusion of multiple published studies in the scoring matrix for comparison identified the highest structural and composition scores when decellularization was performed with SDS at low concentration, for a short period of time and at low temperature. Furthermore, the scoring system indicated that cell attachment and viability cannot be concluded from any other parameter and should therefore always be included in evaluation of decellularization strategies.


Assuntos
Colágeno/metabolismo , Células Epiteliais/metabolismo , Matriz Extracelular/química , Glicosaminoglicanos/química , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Rim/fisiologia , Octoxinol/química , Engenharia Tecidual/métodos , Animais , Colágeno/química , Detergentes , Células Epiteliais/química , Células Epiteliais/citologia , Glicosaminoglicanos/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/química , Rim/química , Suínos
17.
Front Plant Sci ; 8: 381, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28424707

RESUMO

Leucine-Rich Repeats Receptor-Like Kinase (LRR-RLK) genes represent a large and complex gene family in plants, mainly involved in development and stress responses. These receptors are composed of an LRR-containing extracellular domain (ECD), a transmembrane domain (TM) and an intracellular kinase domain (KD). To provide new perspectives on functional analyses of these genes in model and non-model plant species, we performed a phylogenetic analysis on 8,360 LRR-RLK receptors in 31 angiosperm genomes (8 monocots and 23 dicots). We identified 101 orthologous groups (OGs) of genes being conserved among almost all monocot and dicot species analyzed. We observed that more than 10% of these OGs are absent in the Brassicaceae species studied. We show that the ECD structural features are not always conserved among orthologs, suggesting that functions may have diverged in some OG sets. Moreover, we looked at targets of positive selection footprints in 12 pairs of OGs and noticed that depending on the subgroups, positive selection occurred more frequently either in the ECDs or in the KDs.

19.
PLoS One ; 8(10): e78182, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24205149

RESUMO

The wild tomato species Solanum chilense and S. peruvianum are a valuable non-model system for studying plant adaptation since they grow in diverse environments facing many abiotic constraints. Here we investigate the sequence evolution of regulatory regions of drought and cold responsive genes and their expression regulation. The coding regions of these genes were previously shown to exhibit signatures of positive selection. Expression profiles and sequence evolution of regulatory regions of members of the Asr (ABA/water stress/ripening induced) gene family and the dehydrin gene pLC30-15 were analyzed in wild tomato populations from contrasting environments. For S. chilense, we found that Asr4 and pLC30-15 appear to respond much faster to drought conditions in accessions from very dry environments than accessions from more mesic locations. Sequence analysis suggests that the promoter of Asr2 and the downstream region of pLC30-15 are under positive selection in some local populations of S. chilense. By investigating gene expression differences at the population level we provide further support of our previous conclusions that Asr2, Asr4, and pLC30-15 are promising candidates for functional studies of adaptation. Our analysis also demonstrates the power of the candidate gene approach in evolutionary biology research and highlights the importance of wild Solanum species as a genetic resource for their cultivated relatives.


Assuntos
Proteínas de Plantas/genética , Solanum lycopersicum/genética , Adaptação Fisiológica/genética , Adaptação Fisiológica/fisiologia , Secas , Evolução Molecular
20.
PLoS One ; 6(8): e23905, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21887342

RESUMO

BACKGROUND: Reactive astrocytes are implicated in the development and maintenance of neuroinflammation in the demyelinating disease multiple sclerosis (MS). The sphingosine kinase 1 (SphK1)/sphingosine1-phosphate (S1P) receptor signaling pathway is involved in modulation of the inflammatory response in many cell types, but the role of S1P receptor subtype 3 (S1P(3)) signaling and SphK1 in activated rat astrocytes has not been defined. METHODOLOGY/PRINCIPAL FINDINGS: Using immunohistochemistry we observed the upregulation of S1P(3) and SphK1 expression on reactive astrocytes and SphK1 on macrophages in MS lesions. Increased mRNA and protein expression of S1P(3) and SphK1, as measured by qPCR and Western blotting respectively, was observed after treatment of rat primary astrocyte cultures with the pro-inflammatory stimulus lipopolysaccharide (LPS). Activation of SphK by LPS stimulation was confirmed by SphK activity assay and was blocked by the use of the SphK inhibitor SKI (2-(p-hydroxyanilino)-4-(p-chlorphenyl) thiazole. Treatment of astrocytes with a selective S1P(3) agonist led to increased phosphorylation of extracellular signal-regulated kinase (ERK)-1/2), which was further elevated with a LPS pre-challenge, suggesting that S1P(3) upregulation can lead to increased functionality. Moreover, astrocyte migration in a scratch assay was induced by S1P and LPS and this LPS-induced migration was sensitive to inhibition of SphK1, and independent of cell proliferation. In addition, S1P induced secretion of the potentially neuroprotective chemokine CXCL1, which was increased when astrocytes were pre-challenged with LPS. A more prominent role of S1P(3) signaling compared to S1P(1) signaling was demonstrated by the use of selective S1P(3) or S1P(1) agonists. CONCLUSION/SIGNIFICANCE: In summary, our data demonstrate that the SphK1/S1P(3) signaling axis is upregulated when astrocytes are activated by LPS. This signaling pathway appears to play a role in the establishment and maintenance of astrocyte activation. Upregulation of the pathway in MS may be detrimental, e.g. through enhancing astrogliosis, or beneficial through increased remyelination via CXCL1.


Assuntos
Astrócitos/patologia , Inflamação/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Receptores de Lisoesfingolipídeo/metabolismo , Regulação para Cima/fisiologia , Animais , Quimiocina CXCL1 , Inflamação/patologia , Lipopolissacarídeos/farmacologia , Sistema de Sinalização das MAP Quinases , Esclerose Múltipla , Ratos , Transdução de Sinais , Regulação para Cima/efeitos dos fármacos
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