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1.
Genome Announc ; 3(2)2015 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-25792047

RESUMO

Dickeya solani is an important bacterial pathogen of potato cultivars in Europe. Here, we present the draft genome of D. solani strain IFB0099 isolated from potato in Poland that shows a high level of pectinolytic activity and a high virulence. This genome sequence is 5,094,121 bp and contains 4,365 protein-coding sequences.

2.
Mol Ecol Resour ; 14(2): 426-34, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24128146

RESUMO

Next-generation sequencing technologies are extensively used in the field of molecular microbial ecology to describe taxonomic composition and to infer functionality of microbial communities. In particular, the so-called barcode or metagenetic applications that are based on PCR amplicon library sequencing are very popular at present. One of the problems, related to the utilization of the data of these libraries, is the analysis of reads quality and removal (trimming) of low-quality segments, while retaining sufficient information for subsequent analyses (e.g. taxonomic assignment). Here, we present StreamingTrim, a DNA reads trimming software, written in Java, with which researchers are able to analyse the quality of DNA sequences in fastq files and to search for low-quality zones in a very conservative way. This software has been developed with the aim to provide a tool capable of trimming amplicon library data, retaining as much as taxonomic information as possible. This software is equipped with a graphical user interface for a user-friendly usage. Moreover, from a computational point of view, StreamingTrim reads and analyses sequences one by one from an input fastq file, without keeping anything in memory, permitting to run the computation on a normal desktop PC or even a laptop. Trimmed sequences are saved in an output file, and a statistics summary is displayed that contains the mean and standard deviation of the length and quality of the whole sequence file. Compiled software, a manual and example data sets are available under the BSD-2-Clause License at the GitHub repository at https://github.com/GiBacci/StreamingTrim/.


Assuntos
Biologia Computacional/métodos , Metagenômica/métodos , RNA Ribossômico 16S/genética , Análise de Sequência de DNA/métodos , Software
3.
Lett Appl Microbiol ; 48(3): 355-61, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19207854

RESUMO

AIMS: Sinorhizobium meliloti is a nitrogen-fixing alpha-proteobacterium present in soil and symbiotically associated with root nodules of leguminous plants. To date, estimation of bacterial titres in soil is achieved by most-probable-number assays based on the number of nodules on the roots of test plants. Here, we report the development of two real-time PCR (qPCR) assays to detect the presence of S. meliloti in soil and plant tissues by targeting, in a species-specific fashion, the chromosomal gene rpoE1 and the pSymA gene nodC. METHODS AND RESULTS: rpoE1 and nodC primer pairs were tested on DNA extracted from soil samples unspiked and spiked with known titres of S. meliloti and from plant root samples nodulated with S. meliloti. Results obtained were well in agreement with viable titres of S. meliloti cells estimated in the same samples. CONCLUSIONS: The developed qPCR assays appear to be enough sensitive, precise and species-specific to be used as a complementary tool for S. meliloti titre estimation. SIGNIFICANCE AND IMPACT OF THE STUDY: These two novel markers offer the possibility of quick and reliable estimation of S. meliloti titres in soil and plant roots contributing new tools to explore S. meliloti biology and ecology including viable but nonculturable fraction.


Assuntos
DNA Bacteriano/análise , Medicago sativa/microbiologia , Reação em Cadeia da Polimerase/métodos , Sinorhizobium meliloti/isolamento & purificação , Microbiologia do Solo , Proteínas de Bactérias/genética , DNA Bacteriano/isolamento & purificação , N-Acetilglucosaminiltransferases/genética , Nodulação , Raízes de Plantas/microbiologia , Sensibilidade e Especificidade , Sinorhizobium meliloti/classificação , Sinorhizobium meliloti/genética , Especificidade da Espécie , Simbiose
4.
Microb Ecol ; 48(2): 209-17, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15546041

RESUMO

Serpentine soils are characterized by high levels of heavy metals (Ni, Co, Cr), and low levels of important plant nutrients (P, Ca, N). Because of these inhospitable edaphic conditions, serpentine soils are typically home to a very specialized flora including endemic species as the nickel hyperaccumulator Alyssum bertolonii. Although much is known about the serpentine flora, few researches have investigated the bacterial communities of serpentine areas. In the present study bacterial communities were sampled at various distances from A. bertolonii roots in three different serpentine areas and their genetic diversity was assessed by terminal restriction fragment length polymorphism (T-RFLP) analysis. The obtained results indicated the occurrence of a high genetic diversity and heterogeneity of the bacterial communities present in the different serpentine areas. Moreover, TRFs (terminal restriction fragments) common to all the investigated A. bertolonii rhizosphere samples were found. A new cloning strategy was applied to 27 TRFs that were sequenced and taxonomically interpreted as mainly belonging to Gram-positive and alpha-Proteobacteria representatives. In particular, cloned TRFs which discriminated between rhizosphere and soil samples were mainly interpreted as belonging to Proteobacteria representatives.


Assuntos
Bactérias/genética , Brassicaceae/microbiologia , Variação Genética , Raízes de Plantas/microbiologia , Microbiologia do Solo , Sequência de Bases , Clonagem Molecular/métodos , Análise por Conglomerados , Primers do DNA , Enzimas de Restrição do DNA/genética , DNA Ribossômico/genética , Itália , Metais Pesados/análise , Dados de Sequência Molecular , Polimorfismo de Fragmento de Restrição , Análise de Componente Principal , Análise de Sequência de DNA , Solo/análise
5.
Mar Pollut Bull ; 48(5-6): 526-32, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-14980468

RESUMO

The use of sandhoppers and beachfleas as biomonitors of heavy metals contamination is relatively recent. Using adult individuals of Talitrus saltator from nine localities on the northern Mediterranean Sea, we studied the concentrations of eight trace elements: Al, Cd, Cr, Fe, Hg, Pb, Cu, Zn, both in the substratum and in the individuals. We also carried out a preliminary investigation of the correspondence between the sandhoppers' genetic variability and heavy metal contamination at the sampling sites. T. saltator accumulated Cd, Cu, Zn and Hg (at higher concentrations than in the sand) and also Al and Fe (at lower concentrations than in the sand). It seems that Mediterranean sandhoppers do not accumulate Pb and Cr. An intraspecific comparison between northern European (Baltic) and Mediterranean populations of T. saltator was made. Finally, we observed a tendency to a positive correlation between the sandhoppers' genetic variability and heavy metals contamination.


Assuntos
Anfípodes/química , Monitoramento Ambiental/métodos , Metais Pesados/análise , Anfípodes/genética , Animais , Variação Genética , Genética Populacional , Mar Mediterrâneo , Metais Pesados/farmacocinética , Distribuição Tecidual
6.
Mol Ecol ; 10(8): 1909-16, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11555235

RESUMO

Eight populations of Silene paradoxa L. (Caryophyllaceae) growing in copper mine deposits, in serpentine outcrops or in uncontaminated soil in central Italy were studied. Genetic diversity was estimated using five polymorphic chloroplast microsatellite loci (cpSSR), identifying 27 different chloroplast haplotypes. The effective number of alleles, the haplotypic diversity and a stepwise mutational model-based parameter (DSH2) were computed. The effective number of alleles observed within populations from copper mine deposits was 20% that of the serpentine neighbouring populations, suggesting the occurrence of a founder effect. Moreover, 13 of the 27 different haplotypes scored were exclusive to only one population, indicating genetic isolation for all tolerant populations. Even the copper-tolerant populations appeared to have evolved independently. Finally, analysis of molecular variance (AMOVA) of the cpSSR markers gave statistical significance to the grouping of populations according to their geographical location. This study demonstrates that cpSSR markers could be a useful complementary tool to isoenzymes or random amplified polymorphic DNA markers for elucidating the pattern of genetic differentiation in heavy metal-tolerant populations.


Assuntos
DNA de Cloroplastos/genética , Variação Genética , Magnoliopsida/genética , Metais Pesados/metabolismo , Repetições de Microssatélites , Alelos , Cloroplastos/genética , Genes de Plantas , Haplótipos , Itália , Magnoliopsida/metabolismo
7.
Environ Microbiol ; 3(11): 691-8, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11846759

RESUMO

In the present study, heterotrophic nickel-resistant bacteria were isolated and characterized from three different serpentine outcrops in central Italy populated by the nickel-hyperaccumulating plant Alyssum bertolonii. Bacteria were isolated from the rhizosphere of the plant and from soil portions at various distances from the plant. The proportion of nickel-resistant cfu was higher in proximity to the plant than in free soil. A total of 138 isolates was collected and grouped into 47 different operational taxonomic units (OTUs) by means of amplified ribosomal DNA restriction analysis (ARDRA) and into 25 heavy-metal resistant phenotypes. The phylogenetic position of strains belonging to 20 OTUs, representing more than the 70% of the total isolates, was determined by 16S rDNA sequencing. These analyses showed that the most represented genera in all three different outcrops were Pseudomonas and Streptomyces. Pseudomonas strains were found to be predominant in the plant rhizosphere, whereas Streptomyces strains were mainly present in the soil.


Assuntos
Brassicaceae/microbiologia , Níquel/farmacologia , Pseudomonas/fisiologia , Microbiologia do Solo , Streptomyces/fisiologia , Brassicaceae/metabolismo , Contagem de Colônia Microbiana , Farmacorresistência Bacteriana , Itália , Metais/farmacologia , Dados de Sequência Molecular , Filogenia , Pseudomonas/classificação , Pseudomonas/efeitos dos fármacos , Pseudomonas/genética , RNA Ribossômico 16S/análise , Streptomyces/classificação , Streptomyces/efeitos dos fármacos , Streptomyces/genética
8.
Appl Environ Microbiol ; 66(11): 4785-9, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11055924

RESUMO

We analyzed the genetic diversity of 531 Sinorhizobium meliloti strains isolated from nodules of Medicago sativa cultivars in two different Italian soils during 4 years of plant growth. The isolates were analyzed for DNA polymorphism with the random amplified polymorphic DNA method. The populations showed a high level of genetic polymorphism distributed throughout all the isolates, with 440 different haplotypes. Analysis of molecular variance allowed us to relate the genetic structure of the symbiotic population to various factors, including soil type, alfalfa cultivar, individual plants within a cultivar, and time. Some of these factors significantly affected the genetic structure of the population, and their relative influence changed with time. At the beginning of the experiment, the soil of origin and, even more, the cultivar significantly influenced the distribution of genetic variability of S. meliloti. After 3 years, the rhizobium population was altered; it showed a genetic structure based mainly on differences among plants, while the effects of soil and cultivar were not significant.


Assuntos
Variação Genética , Medicago sativa/microbiologia , Sinorhizobium meliloti/crescimento & desenvolvimento , Sinorhizobium meliloti/genética , DNA Bacteriano/análise , DNA Bacteriano/genética , Itália , Técnica de Amplificação ao Acaso de DNA Polimórfico/métodos , Solo , Simbiose
9.
Mol Ecol ; 9(9): 1319-24, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10972771

RESUMO

Metal-contaminated sites can occur naturally in serpentine outcrops or as consequence of anthropogenic activities, such as mining deposits, aerial fallout from smelters and industrial processes. Serpentine outcrops are characterized by high levels of nickel, cobalt and chromium and present a typical vegetation which includes endemisms and plants which also live in uncontaminated soils. These latter metal-tolerant populations provide the opportunity to investigate the first steps in the differentiation of plant populations under severe selection pressure and to select plants to be used in the phytoremediation of industrially contaminated soils. In this report eight populations of Silene paradoxa L. (Caryophyllaceae) growing in copper mine deposits, in serpentine outcrops or in noncontaminated soil in central Italy, were analysed using random amplified polymorphic DNA (RAPD) markers to investigate the pattern of genetic variation. The genetic diversity observed in populations at copper mine deposits was found to be at least as high as that of the neighbouring serpentine populations. Analysis of molecular variance (AMOVA) of the RAPD markers gave high statistical significance to the groupings of populations according: (i) with their geographical location; and (ii) with the metals present in the soil of origin (copper vs. nickel), indicating that RAPD markers detected a polymorphism related to the soil contamination by copper. Finally, two RAPD bands exclusive to copper-tolerant populations were identified.


Assuntos
Magnoliopsida/efeitos dos fármacos , Magnoliopsida/genética , Metais Pesados/toxicidade , Sequência de Bases , Cobre/toxicidade , Primers do DNA/genética , DNA de Plantas/genética , Variação Genética , Genética Populacional , Itália , Filogenia , Técnica de Amplificação ao Acaso de DNA Polimórfico , Seleção Genética , Poluentes do Solo/toxicidade
10.
FEMS Microbiol Lett ; 181(1): 171-6, 1999 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-10564804

RESUMO

In this study the description of a new insertion sequence of Sinorhizobium meliloti, ISRm10, is reported. ISRm10 was found in the intergenic region between nodJ and nodQ of a natural isolated strain. ISRm10 was 1047 bp long and showed the typical features of the ISs belonging to the IS630-Tc1/IS3 superfamily. In particular the ISRm10 nucleotide sequence showed the highest homology (62%) with a Sphingomonas aromaticivorans IS. ISRm10 was present in 32% of the analyzed S. meliloti strains while it was not found in the reference strains of other Rhizobium species.


Assuntos
Elementos de DNA Transponíveis , Sinorhizobium meliloti/genética , Sequência de Bases , Impressões Digitais de DNA , DNA Bacteriano/genética , Medicago sativa/microbiologia , Filogenia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Sinorhizobium meliloti/isolamento & purificação
11.
Br J Cancer ; 77(12): 2148-51, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9649126

RESUMO

We investigated in the rat the role of the Apc gene, which is mutated in familial adenomatous polyposis and sporadic colon cancer in the process leading from normal colonic mucosa to aberrant crypt foci (ACF) and finally to adenomas and adenocarcinomas. We analysed mutations in exon 15 of the rat Apc gene using in vitro synthesized protein assay in 66 ACF and in 28 colon tumours induced by azoxymethane. No Apc mutations were found in ACF, whereas five mutations were found in the tumours. The data suggest that mutations of the Apc gene are associated with the transition from ACF to adenoma and adenocarcinoma and not from normal mucosa to ACF.


Assuntos
Adenocarcinoma/genética , Adenoma/genética , Transformação Celular Neoplásica/genética , Neoplasias Colorretais/genética , Genes APC , Mutação , Lesões Pré-Cancerosas/genética , Adenocarcinoma/induzido quimicamente , Adenoma/induzido quimicamente , Animais , Azoximetano , Carcinógenos , Transformação Celular Neoplásica/efeitos dos fármacos , Neoplasias Colorretais/induzido quimicamente , DNA de Neoplasias/genética , Epitélio/efeitos dos fármacos , Mucosa Intestinal/efeitos dos fármacos , Masculino , Reação em Cadeia da Polimerase , Lesões Pré-Cancerosas/induzido quimicamente , Ratos , Ratos Endogâmicos F344
12.
Antonie Van Leeuwenhoek ; 73(1): 3-8, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9602273

RESUMO

We analysed the genetic diversity of 270 Sinorhizobium meliloti strains isolated from nodules of three different Medicago sativa varieties, planted in three different Italian soils, combining the Analysis of Molecular Variance (AMOVA) with the Random Amplified Polymorphic DNA (RAPD) technique to estimate variance among RAPD patterns with the aim to draw an objective description of the population genetic structure. Results indicated that a general intraspecific genetic diversity was globally distributed among all the population, however a very high level of diversity was found among strains nodulating different Medicago sativa varieties. Moreover the distribution of the RAPD haplotypes among the plant varieties also showed to be non-random. The overall data indicated that the plant genotype is a major factor in shaping the genetic structure of this natural Rhizobium population.


Assuntos
Variação Genética , Medicago sativa/microbiologia , Rhizobiaceae/genética , Análise de Variância , DNA Bacteriano/análise , Genótipo , Haplótipos , Itália , Medicago sativa/genética , Filogenia , Técnica de Amplificação ao Acaso de DNA Polimórfico , Rhizobiaceae/classificação , Rhizobiaceae/isolamento & purificação , Rhizobiaceae/fisiologia , Microbiologia do Solo
13.
Can J Microbiol ; 44(11): 1110-3, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10030007

RESUMO

The characterization of a DNA fragment with a Tn5 insertion in a regulatory nif gene of Azospirillum brasilense is reported. Restriction endonuclease mapping, Southern hybridization with a Tn5 probe, and nucleotide sequencing revealed that IS50 had duplicated in Tn5. The duplication of an IS50 element suggests the occurrence of a replicative mechanism of transposition. A strategy, based on the bacterial ability of homologous recombination that was used to precisely eliminate Tn5 along with the duplicated IS50 element, is presented.


Assuntos
Azospirillum brasilense/genética , Elementos de DNA Transponíveis , Sequência de Bases , Southern Blotting , Mapeamento Cromossômico , DNA Bacteriano/genética , Dados de Sequência Molecular , Mutagênese Insercional , Fixação de Nitrogênio/genética , Recombinação Genética , Mapeamento por Restrição , Transformação Bacteriana
14.
Appl Environ Microbiol ; 62(7): 2279-85, 1996 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8779566

RESUMO

We investigated the genetic diversity of 96 Rhizobium meliloti strains isolated from nodules of four Medicago sativa varieties from distinct geographic areas and planted in two different northern Italian soils. The 96 isolates, which were phenotypically indistinguishable, were analyzed for DNA polymorphism with the following three methods: (i) a randomly amplified polymorphic DNA (RAPD) method, (ii) a restriction fragment length polymorphism (RFLP) analysis of the 16S-23S ribosomal operon spacer region, and (iii) an RFLP analysis of a 25-kb region of the pSym plasmid containing nod genes. Although the bacteria which were studied constituted a unique genetic population, a considerable level of genetic diversity was found. The new analysis of molecular variance (AMOVA) method was used to estimate the variance among the RAPD patterns. The results indicated that there was significant genetic diversity among strains nodulating different varieties. The AMOVA method was confirmed to be a useful tool for investigating the genetic variation in an intraspecific population. Moreover, the data obtained with the two RFLP methods were consistent with the RAPD results. The genetic diversity of the population was found to reside on the whole bacterial genome, as suggested by the RAPD analysis results, and seemed to be distributed on both the chromosome and plasmid pSym.


Assuntos
Medicago sativa/microbiologia , Sinorhizobium meliloti/genética , Sinorhizobium meliloti/isolamento & purificação , Análise de Variância , Sequência de Bases , Mapeamento Cromossômico , Cromossomos Bacterianos/genética , Primers do DNA/genética , DNA Bacteriano/genética , DNA Ribossômico/genética , Variação Genética , Itália , Dados de Sequência Molecular , Plasmídeos/genética , Polimorfismo de Fragmento de Restrição , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , RNA Ribossômico 23S/genética , Técnica de Amplificação ao Acaso de DNA Polimórfico , Microbiologia do Solo , Simbiose
15.
J Bacteriol ; 178(12): 3440-6, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8655539

RESUMO

The lon gene of Escherichia coli encodes the lon (La) protease, which is associated with cellular protein degradation. A lon gene homolog from Azospirillum brasilense, a nitrogen-fixing soil bacterium which lives in association with the roots of cereal grasses, was cloned and characterized. The nucleotide sequence of the A. brasilense lon gene was determined. It contains an open reading frame that encodes a protein of 810 amino acids with a predicted molecular mass of about 90 kDa. The deduced amino acid sequence showed a high level of homology with the sequences of all the known lon gene products. An open reading frame homologous to the E. coli clpX gene was found in front of the lon gene. Transcriptional analysis showed that the lon gene of A. brasilense is induced by heat shock and that the mRNA is monocistronic. An A. brasilense mutant, with Tn5 inserted in the lon gene, was shown to be defective in iron uptake and failed to express two membrane proteins that are induced by iron starvation in the parental strain.


Assuntos
Azospirillum brasilense/genética , Proteínas de Escherichia coli , Genes Bacterianos , Proteínas de Choque Térmico/genética , Protease La , Serina Endopeptidases/genética , Proteases Dependentes de ATP , Sequência de Aminoácidos , Azospirillum brasilense/enzimologia , Sequência de Bases , Transporte Biológico , Clonagem Molecular , Primers do DNA/química , Regulação Bacteriana da Expressão Gênica , Temperatura Alta , Ferro/metabolismo , Dados de Sequência Molecular , Regiões Promotoras Genéticas , RNA Mensageiro/genética , Mapeamento por Restrição , Transcrição Genética , Raios Ultravioleta
18.
FEMS Microbiol Lett ; 129(2-3): 195-200, 1995 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-7607400

RESUMO

The 16S rDNA of 17 strains of Azospirillum, 14 assigned to one of the known species A. amazonense, A. brasilense, A. halopraeferens, A. irakense and A. lipoferum, and the other three of uncertain taxonomic position, was sequenced after polymerase chain reaction amplification and analysed in order to investigate the phylogenetic relationships at the intra-generic and super-generic level. The phylogenetic analysis confirms that the genus Azospirillum constitutes a phylogenetically separate entity within the alpha subclass of Proteobacteria and that the five species are well defined. A. brasilense and A. lipoferum are closely related species and form one cluster together with A. halopraeferens; the pair of species A. amazonense and A. irakense forms a second cluster in which Rhodospirillum centenum is also placed.


Assuntos
Azospirillum/genética , Azospirillum/classificação , Técnicas de Tipagem Bacteriana , Sequência de Bases , DNA Bacteriano/genética , DNA Ribossômico/análise , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 16S/genética
19.
FEMS Microbiol Lett ; 127(1-2): 85-91, 1995 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-7737487

RESUMO

DNA fingerprints of several Azospirillum strains, belonging to the five known species A. amazonense, A. brasilense, A. halopraeferens, A. irakense and A. lipoferum, were obtained by restriction analysis of the amplified 16S rDNA and by restriction fragment length polymorphism of the histidine biosynthetic genes. Data obtained showed that amplified rDNA restriction analysis is an easy, fast, reproducible and reliable tool for identification of Azospirillum strains, mainly at the species level, whereas restriction fragment length polymorphism could, in some cases, differentiate strains belonging to the same species. Moreover, both analyses gave congruent results in grouping strains and in the assignment of new strains to a given species.


Assuntos
Azospirillum/classificação , Azospirillum/genética , DNA Bacteriano/genética , DNA Ribossômico/genética , Histidina/genética , Polimorfismo de Fragmento de Restrição , Azospirillum brasilense/classificação , Azospirillum brasilense/genética , Técnicas de Tipagem Bacteriana , Sequência de Bases , Impressões Digitais de DNA , Primers do DNA/genética , Dados de Sequência Molecular , Óperon , Mapeamento por Restrição , Especificidade da Espécie
20.
J Mol Evol ; 38(5): 489-95, 1994 May.
Artigo em Inglês | MEDLINE | ID: mdl-8028028

RESUMO

The hisA and hisF genes belong to the histidine operon that has been extensively studied in the enterobacteria Escherichia coli and Salmonella typhimurium where the hisA gene codes for the phosphoribosyl-5-amino-1-phosphoribosyl-4-imidazolecarboxamide isomerase (EC 5.3.1.16) catalyzing the fourth step of the histidine biosynthetic pathway, and the hisF gene codes for a cyclase catalyzing the sixth reaction. Comparative analysis of nucleotide and predicted amino acid sequence of hisA and hisF genes in different microorganisms showed extensive sequence homology (43% considering similar amino acids), suggesting that the two genes arose from an ancestral gene by duplication and subsequent evolutionary divergence. A more detailed analysis, including mutual information, revealed an internal duplication both in hisA and hisF genes in each of the considered microorganisms. We propose that the hisA and hisF have originated from the duplication of a smaller ancestral gene corresponding to half the size of the actual genes followed by rapid evolutionary divergence. The involvement of gene elongation, gene duplication, and gene fusion in the evolution of the histidine biosynthetic genes is also discussed.


Assuntos
Aldose-Cetose Isomerases , Aminoidrolases/genética , Evolução Biológica , Genes Bacterianos , Histidina/genética , Isomerases/genética , Família Multigênica , Sequência de Aminoácidos , Aminoidrolases/química , Composição de Bases , Sequência de Bases , DNA , Histidina/biossíntese , Isomerases/química , Dados de Sequência Molecular , Óperon , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido Nucleico
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