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AIM: Our goal was to describe a precision medicine program in a regional academic hospital, characterize features of included patients and present early data on clinical impact. MATERIALS AND METHODS: We prospectively included 163 eligible patients with late-stage cancer of any diagnosis from June 2020 to May 2022 in the Proseq Cancer trial. Molecular profiling of new or fresh frozen tumor biopsies was done by WES and RNAseq with parallel sequencing of non-tumoral DNA as individual reference. Cases were presented at a National Molecular Tumor Board (NMTB) for discussion of targeted treatment. Subsequently, patients were followed for at least 7 months. RESULTS: 80% (N = 131) of patients had a successful analysis done, disclosing at least one pathogenic or likely pathogenic variant in 96%. A strongly or potentially druggable variant was found in 19% and 73% of patients, respectively. A germline variant was identified in 2.5%. Median time from trial inclusion to NMTB decision was one month. One third (N = 44) of patients who underwent molecularly profiling were matched with a targeted treatment, however, only 16% were either treated (N = 16) or are waiting for treatment (N = 5), deteriorating performance status being the primary cause of failure. A history of cancer among 1st degree relatives, and a diagnosis of lung or prostate cancer correlated with greater chance of targeted treatment being available. The response rate of targeted treatments was 40%, the clinical benefit rate 53%, and the median time on treatment was 3.8 months. 23% of patients presented at NMTB were recommended clinical trial participation, not dependent on biomarkers. CONCLUSIONS: Precision medicine in end-stage cancer patients is feasible in a regional academic hospital but should continue within the frame of clinical protocols as few patients benefit. Close collaboration with comprehensive cancer centers ensures expert evaluations and equality in access to early clinical trials and modern treatment.
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Medicina de Precisão , Neoplasias da Próstata , Masculino , Humanos , Medicina de Precisão/métodos , Estudos de Viabilidade , Mutação em Linhagem Germinativa , HospitaisRESUMO
Compelling research has recently shown that cancer is so heterogeneous that single research centres cannot produce enough data to fit prognostic and predictive models of sufficient accuracy. Data sharing in precision oncology is therefore of utmost importance. The Findable, Accessible, Interoperable and Reusable (FAIR) Data Principles have been developed to define good practices in data sharing. Motivated by the ambition of applying the FAIR Data Principles to our own clinical precision oncology implementations and research, we have performed a systematic literature review of potentially relevant initiatives. For clinical data, we suggest using the Genomic Data Commons model as a reference as it provides a field-tested and well-documented solution. Regarding classification of diagnosis, morphology and topography and drugs, we chose to follow the World Health Organization standards, i.e. ICD10, ICD-O-3 and Anatomical Therapeutic Chemical classifications, respectively. For the bioinformatics pipeline, the Genome Analysis ToolKit Best Practices using Docker containers offer a coherent solution and have therefore been selected. Regarding the naming of variants, we follow the Human Genome Variation Society's standard. For the IT infrastructure, we have built a centralized solution to participate in data sharing through federated solutions such as the Beacon Networks.
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Biologia Computacional/métodos , Oncologia/normas , Medicina de Precisão , Genoma Humano , Genômica , Humanos , Disseminação de Informação , Neoplasias/diagnóstico , Neoplasias/tratamento farmacológico , Neoplasias/genéticaRESUMO
BACKGROUND: Diffuse large B-cell lymphoma (DLBCL) is the most frequent lymphoid neoplasm among adults,and approximately 30-40% of patients will experience relapse while 5-10% will suffer from primary refractory disease caused by different mechanisms, including treatment-induced resistance. For refractory and relapsed DLBCL (rrDLBCL) patients, early detection and understanding of the mechanisms controlling treatment resistance are of great importance to guide therapy decisions. Here, we have focused on genetic variations in immune surveillance genes in diagnostic DLBCL (dDLBCL) and rrDLBCL patients to elaborate on the suitability of new promising immunotherapies. METHODS: Biopsies from 30 dDLBCL patients who did not progress or relapse during follow up and 17 rrDLBCL patients with refractory disease or who relapsed during follow up were analyzed by whole-exome sequencing, including matched individual germline samples to include only somatic genetic variants in downstream analysis of a curated list of 58 genes involved in major immune surveillance pathways. RESULTS: More than 70% of both dDLBCLs and rrDLBCLs harbored alterations in immune surveillance genes, but rrDLBCL tumor samples have a lower number of genes affected compared to dDLBCL tumor samples. Increased gene mutation frequencies in rrDLBCLs were observed in more than half of the affected immune surveillance genes than dDLBCLs. CONCLUSION: Genetic variants in the antigen-presenting genes affect a higher number of rrDLBCL patients supporting an important role for these genes in tumor progression and development of refractory disease and relapse.
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Linfoma Difuso de Grandes Células B/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Vigilância Imunológica , Masculino , Pessoa de Meia-Idade , MutaçãoRESUMO
Tuber dormancy and sprouting are commercially important potato traits as long-term tuber storage is necessary to ensure year-round availability. Premature dormancy release and sprout growth in tubers during storage can result in a significant deterioration in product quality. In addition, the main chemical sprout suppressant chlorpropham has been withdrawn in Europe, necessitating alternative approaches for controlling sprouting. Breeding potato cultivars with longer dormancy and slower sprout growth is a desirable goal, although this must be tempered by the needs of the seed potato industry, where dormancy break and sprout vigour are required for rapid emergence. We have performed a detailed genetic analysis of tuber sprout growth using a diploid potato population derived from two highly heterozygous parents. A dual approach employing conventional QTL analysis allied to a combined bulk-segregant analysis (BSA) using a novel potato whole-exome capture (WEC) platform was evaluated. Tubers were assessed for sprout growth in storage at six time-points over two consecutive growing seasons. Genetic analysis revealed the presence of main QTL on five chromosomes, several of which were consistent across two growing seasons. In addition, phenotypic bulks displaying extreme sprout growth phenotypes were subjected to WEC sequencing for performing BSA. The combined BSA and WEC approach corroborated QTL locations and served to narrow the associated genomic regions, while also identifying new QTL for further investigation. Overall, our findings reveal a very complex genetic architecture for tuber sprouting and sprout growth, which has implications both for potato and other root, bulb and tuber crops where long-term storage is essential.
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Solanum tuberosum , Diploide , Exoma , Melhoramento Vegetal , Tubérculos/genética , Solanum tuberosum/genéticaRESUMO
Brown bears (Ursus arctos) hibernate for 5-7 months without eating, drinking, urinating, and defecating at a metabolic rate of only 25% of the summer activity rate. Nonetheless, they emerge healthy and alert in spring. We quantified the biochemical adaptations for hibernation by comparing the proteome, metabolome, and hematological features of blood from hibernating and active free-ranging subadult brown bears with a focus on conservation of health and energy. We found that total plasma protein concentration increased during hibernation, even though the concentrations of most individual plasma proteins decreased, as did the white blood cell types. Strikingly, antimicrobial defense proteins increased in concentration. Central functions in hibernation involving the coagulation response and protease inhibition, as well as lipid transport and metabolism, were upheld by increased levels of very few key or broad specificity proteins. The changes in coagulation factor levels matched the changes in activity measurements. A dramatic 45-fold increase in sex hormone-binding globulin levels during hibernation draws, for the first time, attention to its significant but unknown role in maintaining hibernation physiology. We propose that energy for the costly protein synthesis is reduced by three mechanisms as follows: (i) dehydration, which increases protein concentration without de novo synthesis; (ii) reduced protein degradation rates due to a 6 °C reduction in body temperature and decreased protease activity; and (iii) a marked redistribution of energy resources only increasing de novo synthesis of a few key proteins. The comprehensive global data identified novel biochemical strategies for bear adaptations to the extreme condition of hibernation and have implications for our understanding of physiology in general.
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Fatores de Coagulação Sanguínea/metabolismo , Metabolismo Energético/fisiologia , Hibernação/fisiologia , Globulina de Ligação a Hormônio Sexual/metabolismo , Ursidae/fisiologia , AnimaisRESUMO
KEY MESSAGE: WUE phenotyping and subsequent QTL analysis revealed cytosolic GS genes importance for limiting N loss due to photorespiration under well-watered and well-fertilized conditions. Potato (Solanum tuberosum L.) closes its stomata at relatively low soil water deficits frequently encountered in normal field conditions resulting in unnecessary annual yield losses and extensive use of artificial irrigation. Therefore, unraveling the genetics underpinning variation in water use efficiency (WUE) of potato is important, but has been limited by technical difficulties in assessing the trait on individual plants and thus is poorly understood. In this study, a mapping population of potatoes has been robustly phenotyped, and considerable variation in WUE under well-watered conditions was observed. Two extreme WUE bulks of clones were identified and pools of genomic DNA from them as well as the parents were sequenced and mapped to reference potato genome. Following a novel data analysis approach, two highly resolved QTLs were found on chromosome 1 and 9. Interestingly, three genes encoding isoforms of cytosolic glutamine synthase were located in the QTL at chromosome 1 suggesting a major contribution of this enzyme to photosynthetic efficiency and thus WUE in potato. Indeed, Glutamine synthetase enzyme activity of leaf extracts was measured and found to be correlated with contrasting WUE phenotypes.
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Glutamato-Amônia Ligase/fisiologia , Fotossíntese , Proteínas de Plantas/fisiologia , Locos de Características Quantitativas , Solanum tuberosum/genética , Água/fisiologia , Mapeamento Cromossômico , Citosol/enzimologia , DNA de Plantas/genética , Glutamato-Amônia Ligase/genética , Sequenciamento de Nucleotídeos em Larga Escala , Fenótipo , Folhas de Planta/enzimologia , Proteínas de Plantas/genética , Análise de Sequência de DNA , Solanum tuberosum/enzimologia , Solanum tuberosum/fisiologiaRESUMO
BACKGROUND AND AIMS: To investigate if treatment with non-pooled multi-donor faecal microbiota transplantation (FMT) for four weeks was superior to placebo to induce clinical remission in patients with chronic pouchitis. METHODS: The study was a randomised double-blinded placebo-controlled study with a 4-week intervention period and 12-month follow-up. Eligible patients with chronic pouchitis were recruited from five Danish hospitals. Participants were randomised to non-pooled multi-donor FMT derived from four faecal donors, or placebo. Treatment was delivered daily by enema for two weeks followed by every second day for two weeks. Disease severity was accessed at inclusion and 30-day follow-up, using the Pouchitis Disease Activity Index (PDAI); PDAI <7 was considered equivalent to clinical remission. Faecal samples from participants and donors were analysed by shotgun metagenomic sequencing. RESULTS: Inclusion was stopped after inclusion of 30 participants who were randomised 1:1 for treatment with FMT or placebo. There was no difference in participants achieving clinical remission between the two groups at 30-day follow-up, relative risk 1.0 (95%CI(0.55;1.81)). Treatment with FMT resulted in a clinically relevant increase in adverse events compared to placebo, incidence rate ratio 1.67 (95%CI(1.10;2.52)); no serious adverse events within either group. Faecal microbiota transplantation statistically significantly increased the similarity of participant faecal microbiome to the faecal donor microbiome at 30-days follow-up (p=0.01), which was not seen after placebo. CONCLUSIONS: Non-pooled multi-donor FMT was comparable to placebo in inducing clinical remission in patients with chronic pouchitis but showed a clinically relevant increase in adverse events compared to placebo.
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BACKGROUND: Malignant cells in tumours of B-cell origin account for 0.1% to 98% of the total cell content, depending on disease entity. Recently, gene expression profiles (GEPs) of B-cell lymphomas based on microarray technologies have contributed significantly to improved sub-classification and diagnostics. However, the varying degrees of malignant B-cell frequencies in analysed samples influence the interpretation of the GEPs. Based on emerging next-generation sequencing technologies (NGS) like tag sequencing (tag-seq) for GEP, it is expected that the detection of mRNA transcripts from malignant B-cells can be supplemented. This study provides a quantitative assessment and comparison of the ability of microarrays and tag-seq to detect mRNA transcripts from malignant B-cells. A model system was established by eight serial dilutions of the malignant B-cell lymphoma cell line, OCI-Ly8, into the embryonic kidney cell line, HEK293, prior to parallel analysis by exon microarrays and tag-seq. RESULTS: We identified 123 and 117 differentially expressed genes between pure OCI-Ly8 and HEK293 cells by exon microarray and tag-seq, respectively. There were thirty genes in common, and of those, most were B-cell specific. Hierarchical clustering from all dilutions based on the differentially expressed genes showed that neither technology could distinguish between samples with less than 1% malignant B-cells from non-B-cells. A novel statistical concept was developed to assess the ability to detect single genes for both technologies, and used to demonstrate an inverse proportional relationship with the sample purity. Of the 30 common genes, the detection capability of a representative set of three B-cell specific genes--CD74, HLA-DRA, and BCL6 - was analysed. It was noticed that at least 5%, 13% and 22% sample purity respectively was required for detection of the three genes by exon microarray whereas at least 2%, 4% and 51% percent sample purity of malignant B-cells were required for tag-seq detection. CONCLUSION: A sample purity-dependent loss of the ability to detect genes for both technologies was demonstrated. Taq-seq, in comparison to exon microarray, required slightly less malignant B-cells in the samples analysed in order to detect the two most abundantly expressed of the selected genes. The results show that malignant cell frequency is an important variable, with fundamental impact when interpreting GEPs from both technologies.
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Linfoma de Células B/genética , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Análise de Sequência de RNA/métodos , Antígenos de Diferenciação de Linfócitos B/genética , Linhagem Celular Tumoral , Análise por Conglomerados , Proteínas de Ligação a DNA/genética , Éxons , Células HEK293 , Cadeias alfa de HLA-DR/genética , Antígenos de Histocompatibilidade Classe II/genética , Humanos , Linfoma de Células B/metabolismo , Modelos Genéticos , Proteínas Proto-Oncogênicas c-bcl-6RESUMO
Amyloids are highly abundant in many microbial biofilms and may play an important role in their architecture. Nevertheless, little is known of the amyloid proteins. We report the discovery of a novel functional amyloid expressed by a Pseudomonas strain of the P. fluorescens group. The amyloid protein was purified and the amyloid-like structure verified. Partial sequencing by MS/MS combined with full genomic sequencing of the Pseudomonas strain identified the gene coding for the major subunit of the amyloid fibril, termed fapC. FapC contains a thrice repeated motif that differs from those previously found in curli fimbrins and prion proteins. The lack of aromatic residues in the repeat shows that aromatic side chains are not needed for efficient amyloid formation. In contrast, glutamine and asparagine residues seem to play a major role in amyloid formation as these are highly conserved in curli, prion proteins and FapC. fapC is conserved in many Pseudomonas strains including the opportunistic pathogen P. aeruginosa and is situated in a conserved operon containing six genes, of which one encodes a fapC homologue. Heterologous expression of the fapA-F operon in Escherichia coli BL21(DE3) resulted in a highly aggregative phenotype, showing that the operon is involved in biofilm formation.
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Amiloide/metabolismo , Pseudomonas fluorescens/metabolismo , Sequência de Aminoácidos , Amiloide/genética , Amiloide/ultraestrutura , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Genes Bacterianos , Genômica , Microscopia Eletrônica de Transmissão , Dados de Sequência Molecular , Óperon , Pseudomonas fluorescens/genética , Espectrometria de Massas em TandemRESUMO
Within recent years, many precision cancer medicine initiatives have been developed. Most of these have focused on solid cancers, while the potential of precision medicine for patients with hematological malignancies, especially in the relapse situation, are less elucidated. Here, we present a demographic unbiased and observational prospective study at Aalborg University Hospital Denmark, referral site for 10% of the Danish population. We developed a hematological precision medicine workflow based on sequencing analysis of whole exome tumor DNA and RNA. All steps involved are outlined in detail, illustrating how the developed workflow can provide relevant molecular information to multidisciplinary teams. A group of 174 hematological patients with progressive disease or relapse was included in a non-interventional and population-based study, of which 92 patient samples were sequenced. Based on analysis of small nucleotide variants, copy number variants, and fusion transcripts, we found variants with potential and strong clinical relevance in 62% and 9.5% of the patients, respectively. The most frequently mutated genes in individual disease entities were in concordance with previous studies. We did not find tumor mutational burden or micro satellite instability to be informative in our hematologic patient cohort.
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Colonization of new habitats is expected to require genetic adaptations to overcome environmental challenges. Here, we use full genome re-sequencing and extensive common garden experiments to investigate demographic and selective processes associated with colonization of Japan by Lotus japonicus over the past ~20,000 years. Based on patterns of genomic variation, we infer the details of the colonization process where L. japonicus gradually spread from subtropical conditions to much colder climates in northern Japan. We identify genomic regions with extreme genetic differentiation between northern and southern subpopulations and perform population structure-corrected association mapping of phenotypic traits measured in a common garden. Comparing the results of these analyses, we find that signatures of extreme subpopulation differentiation overlap strongly with phenotype association signals for overwintering and flowering time traits. Our results provide evidence that these traits were direct targets of selection during colonization and point to associated candidate genes.
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Aclimatação/genética , Lotus/genética , Evolução Biológica , Genes de Plantas/genética , Variação Genética , Genoma de Planta/genética , Estudo de Associação Genômica Ampla , Genótipo , Geografia , Japão , Lotus/crescimento & desenvolvimento , Lotus/fisiologia , Fenótipo , Seleção GenéticaAssuntos
Neoplasias da Mama , Carcinoma , Humanos , Feminino , Trastuzumab/uso terapêutico , Paclitaxel/uso terapêuticoRESUMO
BACKGROUND: Radiation-therapy (RT) induces mucositis, a clinically challenging condition with limited prophylactic interventions and no predictive tests. In this pilot study, we applied global gene-expression analysis on serial human oral mucosa tissue and blood cells from patients with tonsil squamous cell cancer (TSCC) to identify genes involved in mucositis pathogenesis. METHODS AND FINDINGS: Eight patients with TSCC each provided consecutive buccal biopsies and blood cells before, after 7 days of RT treatment, and 20 days following RT. We monitored clinical mucositis and performed gene-expression analysis on tissue samples. We obtained control tissue from nine healthy individuals. After RT, expression was upregulated in apoptosis inducer and inhibitor genes, EDA2R and MDM2, and in POLH, a DNA-repair polymerase. Expression was downregulated in six members of the histone cluster family, e.g., HIST1H3B. Gene expression related to proliferation and differentiation was altered, including MKI67 (downregulated), which encodes the Ki-67-proliferation marker, and KRT16 (upregulated), which encodes keratin16. These alterations were not associated with the clinical mucositis grade. However, the expression of LY6G6C, which encodes a surface immunoregulatory protein, was upregulated before treatment in three cases of clinical none/mild mucositis, but not in four cases of ulcerative mucositis. CONCLUSION: RT caused molecular changes related to apoptosis, DNA-damage, DNA-repair, and proliferation without a correlation to the severity of clinical mucositis. LY6G6C may be a potential protective biomarker for ulcerative mucositis. Based on these results, our study model of consecutive human biopsies will be useful in designing a prospective clinical validation trial to characterize molecular mucositis and identify predictive biomarkers.
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Carcinoma de Células Escamosas/genética , Perfilação da Expressão Gênica , Mucosa Bucal/metabolismo , Neoplasias Tonsilares/genética , Idoso , Carcinoma de Células Escamosas/radioterapia , Dano ao DNA , Reparo do DNA , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias Tonsilares/radioterapiaRESUMO
Kleb. is a pathogenic fungus causing wilting, chlorosis, and early dying in potato ( L.). Genetic mapping of resistance to was done using a diploid population of potato. The major quantitative trait locus (QTL) for resistance was found on chromosome 5. The gene, controlling earliness of maturity and tuberization, was mapped within the interval. Another QTL on chromosome 9 co-localized with the wilt resistance gene marker. Epistasis analysis indicated that the loci on chromosomes 5 and 9 had a highly significant interaction, and that functioned downstream of The alleles were sequenced and found to encode StCDF1.1 and StCDF1.3. Interaction between the resistance allele and the was demonstrated, but not for Genome-wide expression QTL (eQTL) analysis was performed and genes with eQTL at the and loci were both found to have similar functions involving the chloroplast, including photosynthesis, which declines in both maturity and wilt. Among the gene ontology (GO) terms that were specific to genes with eQTL at the , but not the locus, were those associated with fungal defense. These results suggest that controls fungal defense and reduces early dying in wilt through affecting genetic pathway controlling tuberization timing.
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Resistência à Doença/genética , Doenças das Plantas/microbiologia , Locos de Características Quantitativas , Solanum tuberosum/fisiologia , Verticillium/patogenicidade , Diploide , Epistasia Genética , Regulação da Expressão Gênica de Plantas , Ontologia Genética , Doenças das Plantas/genética , Proteínas de Plantas/genética , Tubérculos/fisiologia , Solanum tuberosum/genética , Solanum tuberosum/microbiologiaRESUMO
Despite the recent progress in treatment of multiple myeloma (MM), it is still an incurable malignant disease, and we are therefore in need of new risk stratification tools that can help us to understand the disease and optimize therapy. Here we propose a new subtyping of myeloma plasma cells (PCs) from diagnostic samples, assigned by normal B-cell subset associated gene signatures (BAGS). For this purpose, we combined fluorescence-activated cell sorting and gene expression profiles from normal bone marrow (BM) Pre-BI, Pre-BII, immature, naïve, memory, and PC subsets to generate BAGS for assignment of normal BM subtypes in diagnostic samples. The impact of the subtypes was analyzed in 8 available data sets from 1772 patients' myeloma PC samples. The resulting tumor assignments in available clinical data sets exhibited similar BAGS subtype frequencies in 4 cohorts from de novo MM patients across 1296 individual cases. The BAGS subtypes were significantly associated with progression-free and overall survival in a meta-analysis of 916 patients from 3 prospective clinical trials. The major impact was observed within the Pre-BII and memory subtypes, which had a significantly inferior prognosis compared with other subtypes. A multiple Cox proportional hazard analysis documented that BAGS subtypes added significant, independent prognostic information to the translocations and cyclin D classification. BAGS subtype analysis of patient cases identified transcriptional differences, including a number of differentially spliced genes. We identified subtype differences in myeloma at diagnosis, with prognostic impact and predictive potential, supporting an acquired B-cell trait and phenotypic plasticity as a pathogenetic hallmark of MM.
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Subpopulações de Linfócitos B/metabolismo , Mieloma Múltiplo/diagnóstico , Mieloma Múltiplo/mortalidade , Fenótipo , Subpopulações de Linfócitos B/imunologia , Biomarcadores Tumorais , Perfilação da Expressão Gênica , Humanos , Imunofenotipagem , Mieloma Múltiplo/etiologia , Prognóstico , Análise de Sobrevida , TranscriptomaRESUMO
The genome of potato, a major global food crop, was recently sequenced. The work presented here details the integration of the potato reference genome (DM) with a new sequence-tagged site marker-based linkage map and other physical and genetic maps of potato and the closely related species tomato. Primary anchoring of the DM genome assembly was accomplished by the use of a diploid segregating population, which was genotyped with several types of molecular genetic markers to construct a new ~936 cM linkage map comprising 2469 marker loci. In silico anchoring approaches used genetic and physical maps from the diploid potato genotype RH89-039-16 (RH) and tomato. This combined approach has allowed 951 superscaffolds to be ordered into pseudomolecules corresponding to the 12 potato chromosomes. These pseudomolecules represent 674 Mb (~93%) of the 723 Mb genome assembly and 37,482 (~96%) of the 39,031 predicted genes. The superscaffold order and orientation within the pseudomolecules are closely collinear with independently constructed high density linkage maps. Comparisons between marker distribution and physical location reveal regions of greater and lesser recombination, as well as regions exhibiting significant segregation distortion. The work presented here has led to a greatly improved ordering of the potato reference genome superscaffolds into chromosomal "pseudomolecules".
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Mapeamento Cromossômico/normas , Cromossomos de Plantas/genética , Solanum tuberosum/genética , Biomarcadores/metabolismo , Cromossomos de Plantas/metabolismo , Genoma de Planta , Internet , Interface Usuário-ComputadorRESUMO
Late blight, caused by the oomycete Phytophthora infestans, is the most important disease of potato (Solanum tuberosum). Understanding the molecular basis of resistance and susceptibility to late blight is therefore highly relevant for developing resistant cultivars, either by marker-assissted selection or by transgenic approaches. Specific P. infestans races having the Avr1 effector gene trigger a hypersensitive resistance response in potato plants carrying the R1 resistance gene (incompatible interaction) and cause disease in plants lacking R1 (compatible interaction). The transcriptomes of the compatible and incompatible interaction were captured by DeepSAGE analysis of 44 biological samples comprising five genotypes, differing only by the presence or absence of the R1 transgene, three infection time points and three biological replicates. 30,859 unique 21 base pair sequence tags were obtained, one third of which did not match any known potato transcript sequence. Two third of the tags were expressed at low frequency (<10 tag counts/million). 20,470 unitags matched to approximately twelve thousand potato transcribed genes. Tag frequencies were compared between compatible and incompatible interactions over the infection time course and between compatible and incompatible genotypes. Transcriptional changes were more numerous in compatible than in incompatible interactions. In contrast to incompatible interactions, transcriptional changes in the compatible interaction were observed predominantly for multigene families encoding defense response genes and genes functional in photosynthesis and CO(2) fixation. Numerous transcriptional differences were also observed between near isogenic genotypes prior to infection with P. infestans. Our DeepSAGE transcriptome analysis uncovered novel candidate genes for plant host pathogen interactions, examples of which are discussed with respect to possible function.
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Phytophthora infestans/genética , Phytophthora infestans/patogenicidade , Doenças das Plantas/parasitologia , Solanum tuberosum/microbiologia , Transcriptoma/genéticaRESUMO
BACKGROUND: Glucose-6-phosphate is imported into the amyloplast of potato tubers and thought to constitute the precursor for starch synthesis in potato tubers. However, recently it was shown that glucose-1-phosphate can also be imported into the amyloplast and incorporated into starch via an ATP independent mechanism under special conditions. Nonetheless, glucose-6-phosphate is believed to be the quantitatively important precursor for starch synthesis in potato. PRINCIPAL FINDING: Potato tubers of the high yielding cv Kuras had low gene expression of plastidial phophoglucomutase (PGM) and normal levels of transcripts for other enzymes involved in starch metabolism in comparison with medium and low yielding cultivars as determined by DeepSAGE transcriptome profiling. The decrease in PGM activity in Kuras was confirmed by measuring the enzyme activity from potato tuber extracts. Contrary to expectations, this combination lead to a higher level of intracellular glucose-1-phosphate (G1P) in Kuras suggesting that G1P is directly imported into plastids and can be quantitatively important for starch synthesis under normal conditions in high yielding cultivars. SIGNIFICANCE: This could open entirely new possibilities for metabolic engineering of the starch metabolism in potato via the so far uncharacterized G1P transporter. The perspectives are to increase yield and space efficiency of this important crop. In the light of the increasing demands imposed on agriculture to support a growing global population this presents an exciting new possibility.
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Perfilação da Expressão Gênica , Solanum tuberosum/genética , Solanum tuberosum/metabolismo , Amido/biossíntese , Citosol/enzimologia , Citosol/metabolismo , Glucose-6-Fosfato/metabolismo , Glucofosfatos/metabolismo , Hexoses/química , Hexoses/metabolismo , Hidroliases/metabolismo , Espaço Intracelular/metabolismo , Plastídeos/enzimologia , Plastídeos/metabolismo , Solanum tuberosum/citologia , Solanum tuberosum/crescimento & desenvolvimento , Sacarose/química , Sacarose/metabolismoRESUMO
TFIIS is a transcript elongation factor that facilitates transcription by RNA polymerase II through blocks to elongation. Arabidopsis plants lacking TFIIS are affected in seed dormancy, which represents a block to complete germination under favourable conditions. We have comparatively profiled the transcript levels of seeds of tfIIs mutants and control plants. Among the differentially expressed genes, the DOG1 gene was identified that is a QTL for seed dormancy. The reduced expression of DOG1 in tfIIs seeds was confirmed by quantitative RT-PCR and Northern analyses, suggesting that down-regulation of DOG1 expression is involved in the seed dormancy phenotype of tfIIs mutants.