RESUMO
Sudden cardiac death (SCD) is a major public health concern worldwide, and genetic analysis may be useful in identifying the cause of death as well as in determining the possible genetic risk factors for SCD. This study analyzed eight SNPs (single nucleotide polymorphisms) highly correlated with cardiac sudden death in samples (blood and bone) from six Brazilian families with a history of cardiovascular diseases. Individuals with no family history of cardiovascular diseases were recruited as controls. Y chromosomes and mtDNA haplogroups belonging to these subjects were verified as well. We found that SNP rs16857031 showed significant differences between the group with a family history of cardiovascular diseases and the control group. Furthermore, the data obtained were compatible with known frequencies of SNPs for the haplogroups in which the samples were classified. A possible hereditary factor was identified for SNP rs4725982 in one family. These preliminary results suggest that identification of certain SNPs could be used to assess risk factors for SCD.
Assuntos
Cardiomiopatias/genética , Morte Súbita Cardíaca , Marcadores Genéticos/genética , Adulto , Idoso , Brasil , Estudos de Casos e Controles , Feminino , Estudos de Associação Genética , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Multiplex , Linhagem , Polimorfismo de Nucleotídeo Único , Fatores de RiscoRESUMO
A fermentation system was continuously fed with sugar-cane syrup and operated with recycling of Saccharomyces cerevisiae cells at temperatures varying from 30 to 47 °C. The aim of the present work was to obtain and study the colonies of isolates showing elongated cells of yeasts which were sporadically observed at the end of this continuous process. Based on a sequence of assays involving methods of classical taxonomy and RAPD-PCR, two groups of isolates showing characteristics of non-Saccharomyces yeasts were identified in the yeast population where S. cerevisiae was the dominant yeast. The largest group of non-Saccharomyces yeasts, resulting from a slow proliferation over the 2 months, reached a final level of 29.6% at the end of the process. RAPD-PCR profiles obtained for the isolates of this dominant non-Saccharomyces yeast indicated that they were isolates of Issatchenkia orientalis. Pichia membranifaciens was the only species of non-Saccharomyces yeast detected together with I. orientalis but at a very low frequency. The optimum temperature for ethanol formation shown by the isolate 195B of I. orientalis was 42 °C. This strain also showed a faster ethanol formation and biomass accumulation than the thermotolerant strain of S. cerevisiae used as the starter of this fermentation process. Some isolates of I. orientalis were also able to grow better at 40 °C than at 30 °C on plates containing glycerol as carbon source. Yeasts able to grow and produce ethanol at high temperatures can extend the fermentation process beyond the temperature limits tolerated by S. cerevisiae.
Assuntos
Etanol/metabolismo , Fermentação , Saccharomyces cerevisiae/crescimento & desenvolvimento , Saccharomyces cerevisiae/metabolismo , Saccharomycetales/crescimento & desenvolvimento , Biomassa , DNA Fúngico/análise , Microbiologia Industrial , Pichia/crescimento & desenvolvimento , Técnica de Amplificação ao Acaso de DNA Polimórfico , Saccharomycetales/classificação , Saccharomycetales/isolamento & purificação , TemperaturaRESUMO
As data on X-chromosomal short tandem repeats (X-STRs) for the Brazilian population are scarse, the aim of this study was to determine the allele frequencies of five X-STRs (DXS6854, DXS7424, DXS101, DXS6808 and DXS7132) in the São Paulo State, Brazil. No deviations from the Hardy-Weinberg equilibrium were observed, with the exception of DXS101. The forensic efficiency parameters demonstrated that DXS101 was the most informative marker. Population comparisons revealed that the X-STR profile sampled in the state of São Paulo was more similar to European and African populations than Asiatic populations reported in this work.
Assuntos
Cromossomos Humanos X/genética , Variação Genética , Genética Populacional , Brasil , Feminino , Frequência do Gene/genética , Humanos , Masculino , Repetições de Microssatélites/genéticaRESUMO
Oil extraction from green coffee seeds generates residual mass that is discarded by agribusiness and has not been previously studied. Bioactive secondary metabolites in coffee include antioxidant phenolic compounds, such as chlorogenic acids. Coffee seeds also contain caffeine, a pharmaceutically important methylxanthine. Here, we report the chemical profile, antioxidant activity, and cytotoxicity of hydroethanolic extracts of green Coffea arabica L. seed residue. The extracts of the green seeds and the residue have similar chemical profiles, containing the phenolic compounds chlorogenic acid and caffeine. Five monoacyl and three diacyl esters of trans-cinnamic acids and quinic acid were identified by ultra-performance liquid chromatography/electrospray ionization-quadruple time of flight mass spectrometry. The residue extract showed antioxidant potential in DPPH, ABTS, and pyranine assays and low cytotoxicity. Thus, coffee oil residue has great potential for use as a raw material in dietary supplements, cosmetic and pharmaceutical products, or as a source of bioactive compounds.
Assuntos
Antioxidantes/farmacologia , Coffea/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Sementes/química , Antioxidantes/química , Sulfonatos de Arila/química , Cafeína/análise , Linhagem Celular , Ácido Clorogênico/análise , Suplementos Nutricionais , Manipulação de Alimentos , Humanos , Fenóis/análise , Ácido Quínico/análise , Resíduos/análise , Xantinas/análiseRESUMO
A collaborative effort was carried out by the Spanish and Portuguese Speaking Working Group of the International Society for Forensic Genetics (GHEP-ISFG) to promote knowledge exchange between associate laboratories interested in the implementation of indel-based methodologies and build allele frequency databases of 38 indels for forensic applications. These databases include populations from different countries that are relevant for identification and kinship investigations undertaken by the participating laboratories. Before compiling population data, participants were asked to type the 38 indels in blind samples from annual GHEP-ISFG proficiency tests, using an amplification protocol previously described. Only laboratories that reported correct results contributed with population data to this study. A total of 5839 samples were genotyped from 45 different populations from Africa, America, East Asia, Europe and Middle East. Population differentiation analysis showed significant differences between most populations studied from Africa and America, as well as between two Asian populations from China and East Timor. Low FST values were detected among most European populations. Overall diversities and parameters of forensic efficiency were high in populations from all continents.
Assuntos
Genética Populacional , Mutação INDEL , Polimorfismo de Nucleotídeo Único , Grupos Raciais/genética , Impressões Digitais de DNA , Bases de Dados de Ácidos Nucleicos , Etnicidade/genética , Frequência do Gene , Genótipo , Humanos , Laboratórios/estatística & dados numéricos , Repetições de MicrossatélitesRESUMO
No fully effective treatment has been developed since the discovery of Chagas' disease by Carlos Chagas in 1909. Since drug-resistant Trypanosoma cruzi strains are occurring and the current therapy is effectiveness in the acute phase but with various adverse side effects, more studies are needed to characterize the susceptibility of T. cruzi to new drugs. Many natural and/or synthetic substances showing trypanocidal activity have been used, even though they are not likely to be turned into clinically approved drugs. Originally, drug screening was performed using natural products, with only limited knowledge of the molecular mechanism involved in the development of diseases. Trans-splicing, which is unusual RNA processing reaction and occurs in nematodes and trypanosomes, implies the processing of polycistronic transcription units into individual mRNAs; a short transcript spliced leader (SL RNA) is trans-spliced to the acceptor pre-mRNA, giving origin to the mature mRNA. In the present study, permeable cells of T. cruzi epimastigote forms (Y, BOL and NCS strains) were treated to evaluate the interference of two drugs (hydroxymethylnitrofurazone - NFOH-121 and nitrofurazone) in the trans-splicing reaction using silver-stained PAGE analysis. Both drugs induced a significant reduction in RNA processing at concentrations from 5 to 12.5 microM. These data agreed with the biological findings, since the number of parasites decreased, especially with NFOH-121. This proposed methodology allows a rapid and cost-effective screening strategy for detecting drug interference in the trans-splicing mechanism of T. cruzi.
Assuntos
Nitrofurazona/análogos & derivados , Nitrofurazona/farmacologia , Pró-Fármacos/farmacologia , RNA Mensageiro/efeitos dos fármacos , RNA de Protozoário/efeitos dos fármacos , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Permeabilidade da Membrana Celular/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Resistência a Medicamentos , Eletroforese em Gel de Poliacrilamida , Splicing de RNA/efeitos dos fármacos , RNA Mensageiro/metabolismo , RNA de Protozoário/metabolismo , RNA Nuclear Pequeno/efeitos dos fármacos , RNA Nuclear Pequeno/metabolismo , Fatores de Tempo , Transcrição Gênica/efeitos dos fármacos , Trypanosoma cruzi/genéticaRESUMO
We detected anti-human small nuclear ribonucleoprotein (snRNP) autoantibodies in chagasic patients by different immunological methods using HeLa snRNPs. ELISA with Trypanosoma cruzi total lysate antigen or HeLa human U small nuclear ribonucleoproteins (UsnRNPs) followed by incubation with sera from chronic chagasic and non-chagasic cardiac patients was used to screen and compare serum reactivity. Western blot analysis using a T. cruzi total cell extract was also performed in order to select some sera for Western blot and immunoprecipitation assays with HeLa nuclear extract. ELISA showed that 73 and 95% of chronic chagasic sera reacted with HeLa UsnRNPs and T. cruzi antigens, respectively. The Western blot assay demonstrated that non-chagasic cardiac sera reacted with high molecular weight proteins present in T. cruzi total extract, probably explaining the 31% reactivity found by ELISA. However, these sera reacted weakly with HeLa UsnRNPs, in contrast to the chagasic sera, which showed autoantibodies with human Sm (from Stefanie Smith, the first patient in whom this activity was identified) proteins (B/B', D1, D2, D3, E, F, and G UsnRNP). Immunoprecipitation reactions using HeLa nuclear extracts confirmed the reactivity of chagasic sera and human UsnRNA/RNPs, while the other sera reacted weakly only with U1snRNP. These findings agree with previously reported data, thus supporting the idea of the presence of autoimmune antibodies in chagasic patients. Interestingly, non-chagasic cardiac sera also showed reactivity with T. cruzi antigen and HeLa UsnRNPs, which suggests that individuals with heart disease of unknown etiology may develop autoimmune antibodies at any time. The detection of UsnRNP autoantibodies in chagasic patients might contribute to our understanding of how they develop upon initial T. cruzi infection.
Assuntos
Autoanticorpos/sangue , Doença de Chagas/imunologia , Ribonucleoproteínas Nucleares Pequenas/imunologia , Trypanosoma cruzi/imunologia , Animais , Autoanticorpos/imunologia , Western Blotting , Doença Crônica , Reações Cruzadas/imunologia , Ensaio de Imunoadsorção Enzimática , Células HeLa/imunologia , Humanos , Testes de PrecipitinaRESUMO
Mitochondrial DNA (mtDNA) population data for forensic purposes are still scarce for some populations, which may limit the evaluation of forensic evidence especially when the rarity of a haplotype needs to be determined in a database search. In order to improve the collection of mtDNA lineages from the Iberian and South American subcontinents, we here report the results of a collaborative study involving nine laboratories from the Spanish and Portuguese Speaking Working Group of the International Society for Forensic Genetics (GHEP-ISFG) and EMPOP. The individual laboratories contributed population data that were generated throughout the past 10 years, but in the majority of cases have not been made available to the scientific community. A total of 1019 haplotypes from Iberia (Basque Country, 2 general Spanish populations, 2 North and 1 Central Portugal populations), and Latin America (3 populations from São Paulo) were collected, reviewed and harmonized according to defined EMPOP criteria. The majority of data ambiguities that were found during the reviewing process (41 in total) were transcription errors confirming that the documentation process is still the most error-prone stage in reporting mtDNA population data, especially when performed manually. This GHEP-EMPOP collaboration has significantly improved the quality of the individual mtDNA datasets and adds mtDNA population data as valuable resource to the EMPOP database (www.empop.org).
Assuntos
Comportamento Cooperativo , DNA Mitocondrial/genética , Genética Populacional , Análise de Sequência de DNA , Sociedades Científicas , Bases de Dados de Ácidos Nucleicos , Haplótipos , Humanos , Internacionalidade , Dados de Sequência MolecularRESUMO
Allele frequency distributions and population data for 12 Y-chromosomal short tandem repeats (STRs) included in the PowerPlex Y Systems (Promega) were obtained for a sample of 200 healthy unrelated males living in São Paulo State (Southeast of Brazil). A total of 192 haplotypes were identified, of which 184 were unique and 8 were found in 2 individuals. The average gene diversity of the 12 Y-STR was 0.6746 and the haplotype diversity was 0.9996. Pairwise analysis confirmed that our population is more similar with the Italy, North Portugal and Spain, being more distant of the Japan.
Assuntos
Cromossomos Humanos Y , Frequência do Gene , Genética Populacional , Sequências de Repetição em Tandem , Brasil , Impressões Digitais de DNA , Haplótipos , Humanos , Masculino , Reação em Cadeia da PolimeraseRESUMO
We report the results of the seventh edition of the GEP-ISFG mitochondrial DNA (mtDNA) collaborative exercise. The samples submitted to the participant laboratories were blood stains from a maternity case and simulated forensic samples, including a case of mixture. The success rate for the blood stains was moderate ( approximately 77%); even though four inexperienced laboratories concentrated about one-third of the total errors. A similar success was obtained for the analysis of mixed samples (78.8% for a hair-saliva mixture and 69.2% for a saliva-saliva mixture). Two laboratories also dissected the haplotypes contributing to the saliva-saliva mixture. Most of the errors were due to reading problems and misinterpretation of electropherograms, demonstrating once more that the lack of a solid devised experimental approach is the main cause of error in mtDNA testing.
Assuntos
Artefatos , Técnicas de Laboratório Clínico/normas , Impressões Digitais de DNA/normas , DNA Mitocondrial/genética , DNA/isolamento & purificação , Manchas de Sangue , Simulação por Computador , DNA/análise , DNA/genética , DNA Mitocondrial/sangue , DNA Mitocondrial/química , Interpretação Estatística de Dados , Bases de Dados Factuais , Feminino , Medicina Legal , Marcadores Genéticos , Cabelo/química , Haplótipos , Humanos , Filogenia , Reação em Cadeia da Polimerase , Polimorfismo Genético , Gravidez , Controle de Qualidade , Padrões de Referência , Saliva/químicaRESUMO
Small nuclear RNAs (snRNAs) are important factors in the functioning of eukaryotic cells that form several small complexes with proteins; these ribonucleoprotein particles (U snRNPs) have an essential role in the pre-mRNA processing, particularly in splicing, catalyzed by spliceosomes, large RNA-protein complexes composed of various snRNPs. Even though they are well defined in mammals, snRNPs are still not totally characterized in certain trypanosomatids as Trypanosoma cruzi. For this reason we subjected snRNAs (U2, U4, U5, and U6) from T. cruzi epimastigotes to molecular characterization by polymerase chain reaction (PCR) and reverse transcription-PCR. These amplified sequences were cloned, sequenced, and compared with those other of trypanosomatids. Among these snRNAs, U5 was less conserved and U6 the most conserved. Their respective secondary structures were predicted and compared with known T. brucei structures. In addition, the copy number of each snRNA in the T. cruzi genome was characterized by Southern blotting.
Assuntos
Genoma de Protozoário/genética , RNA Nuclear Pequeno/genética , Trypanosoma cruzi/genética , Animais , Southern Blotting , Clonagem Molecular , Reação em Cadeia da Polimerase/métodos , Splicing de RNA , Análise de Sequência de DNARESUMO
A protein from Trypanosoma cruzi bloodstream trypomastigotes that binds IgG from man and several other animal species was isolated and characterized. The 52-kDa protein obtained from different T. cruzi cell extracts showed saturable binding with a K of 3.72 nM. Immunoblot analysis revealed that Fab, but not Fc, fragments of the Ig were recognized. When the protein was added to an unrelated C-fixation reaction, lysis was abolished in a dose-dependent fashion. When freshly prepared T. cruzi extracts were run in a 10% acrylamide SDS gel into which normal rabbit IgG was incorporated before polymerization, proteolytic activity, as seen by a transparent band after Coomassie blue staining, migrated in the same m.w. range of the 52-kDa protein. These data provide further clues to the mechanisms through which this pathogen escapes the host's immune response, thus maintaining a long-standing infection.
Assuntos
Sítios de Ligação de Anticorpos , Fragmentos Fab das Imunoglobulinas/metabolismo , Imunoglobulina G/metabolismo , Trypanosoma cruzi/análise , Glicoproteínas Variantes de Superfície de Trypanosoma/fisiologia , Animais , Afinidade de Anticorpos , Ligação Competitiva , Proteínas de Transporte/isolamento & purificação , Proteínas de Transporte/fisiologia , Cromatografia de Afinidade , Feminino , Humanos , Hidrólise , Imunoglobulina G/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Peso Molecular , Coelhos , Trypanosoma cruzi/fisiologia , Tripsina , Glicoproteínas Variantes de Superfície de Trypanosoma/isolamento & purificação , Glicoproteínas Variantes de Superfície de Trypanosoma/metabolismoRESUMO
We investigated the possibility that Chagas' patients develop an autoimmune response to human UsnRNPs (small nuclear ribonucleoprotein) or Sm epitopes. Using purified human UsnRNPs, we detected anti-human UsnRNPs antibodies in sera from patients suffering from Chagas' disease. The antibodies were also detected using peptide enzyme-linked immunosorbent assays containing the Sm-motif 1 domain. The latter technique showed that 61% (31/51) of the Chagas' patients' sera contained antibodies against Sm-motif 1. The detection of anti-UsnRNPs autoantibodies in Chagas' patients' sera strongly encourages further studies using animal models to determine how these autoantibodies appear.
Assuntos
Autoanticorpos/sangue , Doença de Chagas/imunologia , Ribonucleoproteínas Nucleares Pequenas/imunologia , Animais , Autoimunidade , Western Blotting , Ensaio de Imunoadsorção Enzimática , Epitopos/imunologia , Células HeLa , Humanos , Ribonucleoproteínas Nucleares Pequenas/isolamento & purificação , Trypanosoma cruzi/imunologiaRESUMO
Pre-mRNA maturation in trypanosomatids occurs through a process called trans-splicing which involves excision of introns and union of exons in two independent transcripts. For the first time, we present the standardization of Trypanosoma cruzi permeable cells (Y strain) as a model for trans-splicing study of mRNAs in trypanosomes, following by RNase protection reaction, which localizes the SL exon and intron. This trans-splicing reaction in vitro was also used to analyze the influence of NFOH-121, a nitrofurazone-derivative, on this mechanism. The results suggested that the prodrug affects the RNA processing in these parasites, but the trans-splicing reaction still occurred.
Assuntos
Nitrofurazona/análogos & derivados , Nitrofurazona/farmacologia , Splicing de RNA/efeitos dos fármacos , RNA Mensageiro/efeitos dos fármacos , RNA de Protozoário/efeitos dos fármacos , Tripanossomicidas/farmacologia , Trypanosoma cruzi/genética , Animais , Permeabilidade da Membrana Celular/efeitos dos fármacos , Éxons/genética , Íntrons/genética , Fatores de Tempo , Transcrição Gênica/efeitos dos fármacos , Trypanosoma cruzi/efeitos dos fármacos , Trypanosoma cruzi/crescimento & desenvolvimentoRESUMO
We describe a defective HeLa nuclear extract which is particularly deficient in step 2 of splicing reaction. With this extract we have studied the conservation of a second-step activity from yeast to human cells. We detected a S. cerevisiae second-step splicing activity that allows restoration of step 2 of the defective HeLa nuclear extract, which indicates that yeast purified fraction has a second-step activity that is conserved from yeast to human cells. The activity is a yeast UsnRNP protein(s) since it is purified with anti-trimethylguanosine by immunoaffinity columns.
Assuntos
Evolução Biológica , Splicing de RNA , Cromatografia de Afinidade , Teste de Complementação Genética , Globinas/genética , Células HeLa , Humanos , Precursores de RNA/genética , Precursores de RNA/metabolismo , Splicing de RNA/genética , Ribonucleoproteínas Nucleares Pequenas/isolamento & purificação , Ribonucleoproteínas Nucleares Pequenas/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismoRESUMO
Small nuclear ribonucleoproteins (snRNPs) are involved in trans-splicing processing of pre-mRNA in Trypanosoma cruzi. To clone T. cruzi snRNPs we screened an epimastigote cDNA library with a purified antibody raised against the Sm-binding site of a yeast sequence. A clone was obtained containing a 507 bp-insert with an ORF of 399 bp and coding for a protein of 133 amino acids. Sequence analysis revealed high identity with the L27 ribosomal proteins from different species including: Canis familiaris, Homo sapiens, Schizosaccharomyces pombe and Saccharomyces cerevisiae. This protein has not been previously described in the literature and seems to be a new ribosomal protein in T. cruzi and was given the code TcrL27. To express this recombinant T. cruzi L27 ribosomal protein in E. coli, the insert was subcloned into the pET32a vector and a 26 kDa recombinant protein was purified. Immunoblotting studies demonstrated that this purified recombinant protein was recognized by the same anti-Sm serum used in the library screening as well as by chagasic and systemic lupus erythemathosus (SLE) sera. Our results suggest that the T. cruzi L27 ribosomal protein may be involved in autoimmunity of Chagas disease.
Assuntos
Autoanticorpos/sangue , Autoimunidade/imunologia , Doença de Chagas/imunologia , Ribonucleoproteínas Nucleares Pequenas/imunologia , Proteínas Ribossômicas/imunologia , Trypanosoma cruzi/genética , Sequência de Aminoácidos , Animais , Autoantígenos/imunologia , Autoimunidade/genética , Southern Blotting , Western Blotting , Clonagem Molecular , Reações Cruzadas , DNA Complementar/química , DNA de Protozoário/química , DNA de Protozoário/isolamento & purificação , Eletroforese em Gel de Poliacrilamida , Humanos , Dados de Sequência Molecular , Coelhos , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/imunologia , Proteínas Ribossômicas/química , Proteínas Ribossômicas/genética , Alinhamento de Sequência , Trypanosoma cruzi/imunologia , Proteínas Centrais de snRNPRESUMO
Two regions common to all UsnRNP core polypeptides have been described: Sm motif 1 and Sm motif 2. Rabbits were immunized with a 22 amino-acid peptide containing one segment of Sm motif 1 (YRGTLVSTDNYFNLQLNEAEEF, corresponding to residues 11-32) from yeast F protein. After immunization, the rabbit sera contained antibodies that not only reacted specifically with the peptide from yeast F protein but also cross-reacted with Sm polypeptides from mammals; that is, with purified human U1snRNPs. The results suggest that the peptide used and human Sm polypeptides contain a common feature recognized by the polyclonal antibodies. A large collection of human systemic lupus erythematosus sera was assayed using the yeast peptide as an antigen source. Seventy per cent of systemic lupus erythematosus sera contain an antibody specificity that cross-reacts with the yeast peptide.
Assuntos
Anticorpos Antifúngicos/metabolismo , Autoantígenos/imunologia , Proteínas Fúngicas/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Ribonucleoproteínas Nucleares Pequenas/imunologia , Sequência de Aminoácidos , Reações Cruzadas , Humanos , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos , Proteínas Centrais de snRNPRESUMO
2,2,7-trimethylguanosine (TMG) binding proteins from human cells were purified through TMG-affinity columns. TMG synthesis was improved and the TMG obtained was shown to be similar to the TMG in the 5' cap of the UsnRNAs. The eluates obtained with TMG-affinity chromatographies were very different from those isolated with m7G-affinity columns, thus suggesting that specific TMG-binding proteins were obtained. The fraction may be enriched with factors associated with import and/or hypermethylation of UsnRNPs.
Assuntos
Proteínas de Transporte/isolamento & purificação , Cromatografia de Afinidade/métodos , Guanosina/análogos & derivados , Proteínas Nucleares/isolamento & purificação , Animais , Anticorpos , Anticorpos Monoclonais , Núcleo Celular/química , Cromatografia de Afinidade/instrumentação , Citoplasma/química , Proteínas Fúngicas/isolamento & purificação , Guanosina/síntese química , Células HeLa , Hemocianinas , Humanos , Camundongos , Coelhos , Saccharomyces cerevisiae , Sefarose , Albumina SéricaRESUMO
The genus Xanthomonas is a diverse and economically important group of bacterial phytopathogens, belonging to the gamma-subdivision of the Proteobacteria. Xanthomonas axonopodis pv. citri (Xac) causes citrus canker, which affects most commercial citrus cultivars, resulting in significant losses worldwide. Symptoms include canker lesions, leading to abscission of fruit and leaves and general tree decline. Xanthomonas campestris pv. campestris (Xcc) causes black rot, which affects crucifers such as Brassica and Arabidopsis. Symptoms include marginal leaf chlorosis and darkening of vascular tissue, accompanied by extensive wilting and necrosis. Xanthomonas campestris pv. campestris is grown commercially to produce the exopolysaccharide xanthan gum, which is used as a viscosifying and stabilizing agent in many industries. Here we report and compare the complete genome sequences of Xac and Xcc. Their distinct disease phenotypes and host ranges belie a high degree of similarity at the genomic level. More than 80% of genes are shared, and gene order is conserved along most of their respective chromosomes. We identified several groups of strain-specific genes, and on the basis of these groups we propose mechanisms that may explain the differing host specificities and pathogenic processes.