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1.
Appl Environ Microbiol ; 76(22): 7482-90, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20851965

RESUMO

High-grain adaptation programs are widely used with feedlot cattle to balance enhanced growth performance against the risk of acidosis. This adaptation to a high-grain diet from a high-forage diet is known to change the rumen microbial population structure and help establish a stable microbial population within the rumen. Therefore, to evaluate bacterial population dynamics during adaptation to a high-grain diet, 4 ruminally cannulated beef steers were adapted to a high-grain diet using a step-up diet regimen containing grain and hay at ratios of 20:80, 40:60, 60:40, and 80:20. The rumen bacterial populations were evaluated at each stage of the step-up diet after 1 week of adaptation, before the steers were transitioned to the next stage of the diet, using terminal restriction fragment length polymorphism (T-RFLP) analysis, 16S rRNA gene libraries, and quantitative real-time PCR. The T-RFLP analysis displayed a shift in the rumen microbial population structure during the final two stages of the step-up diet. The 16S rRNA gene libraries demonstrated two distinct rumen microbial populations in hay-fed and high-grain-fed animals and detected only 24 common operational taxonomic units out of 398 and 315, respectively. The 16S rRNA gene libraries of hay-fed animals contained a significantly higher number of bacteria belonging to the phylum Fibrobacteres, whereas the 16S rRNA gene libraries of grain-fed animals contained a significantly higher number of bacteria belonging to the phylum Bacteroidetes. Real-time PCR analysis detected significant fold increases in the Megasphaera elsdenii, Streptococcus bovis, Selenomonas ruminantium, and Prevotella bryantii populations during adaptation to the high-concentrate (high-grain) diet, whereas the Butyrivibrio fibrisolvens and Fibrobacter succinogenes populations gradually decreased as the animals were adapted to the high-concentrate diet. This study evaluates the rumen microbial population using several molecular approaches and presents a broader picture of the rumen microbial population structure during adaptation to a high-grain diet from a forage diet.


Assuntos
Bactérias/classificação , Bactérias/genética , Biodiversidade , Dieta/métodos , Metagenoma , Rúmen/microbiologia , Animais , Bovinos , Análise por Conglomerados , Impressões Digitais de DNA , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Grão Comestível , Dados de Sequência Molecular , Filogenia , Polimorfismo de Fragmento de Restrição , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
2.
Insect Mol Biol ; 19 Suppl 2: 155-64, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20482647

RESUMO

Herbivorous insects use detoxification enzymes, including cytochrome P450 monooxygenases, glutathione S-transferases, and carboxy/cholinesterases, to metabolize otherwise deleterious plant secondary metabolites. Whereas Acyrthosiphon pisum (pea aphid) feeds almost exclusively from the Fabaceae, Myzus persicae (green peach aphid) feeds from hundreds of species in more than forty plant families. Therefore, M. persicae as a species would be exposed to a greater diversity of plant secondary metabolites than A. pisum, and has been predicted to require a larger complement of detoxification enzymes. A comparison of M. persicae cDNA and A. pisum genomic sequences is partially consistent with this hypothesis. There is evidence of at least 40% more cytochrome P450 genes in M. persicae than in A. pisum. In contrast, no major differences were found between the two species in the numbers of glutathione S-transferases, and carboxy/cholinesterases. However, given the incomplete M. persicae cDNA data set, the number of identified detoxification genes in this species is likely to be an underestimate.


Assuntos
Afídeos/enzimologia , Afídeos/genética , Genoma de Inseto , Sequência de Aminoácidos , Animais , Sequência de Bases , Biotransformação/genética , Hidrolases de Éster Carboxílico/genética , Hidrolases de Éster Carboxílico/metabolismo , Colinesterases/genética , Colinesterases/metabolismo , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Primers do DNA/genética , DNA Complementar/genética , Evolução Molecular , Etiquetas de Sequências Expressas , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Dados de Sequência Molecular , Pisum sativum/metabolismo , Pisum sativum/parasitologia , Filogenia , Prunus/metabolismo , Prunus/parasitologia , Homologia de Sequência de Aminoácidos , Especificidade da Espécie
3.
J Med Entomol ; 46(5): 1109-16, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19769042

RESUMO

We used an expressed sequence tag and 454 pyrosequencing approach to initiate a study of the genome of the screwworm, Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae). Two normalized cDNA libraries were constructed from RNA isolated from embryos and second instar larvae from the Panama 95 strain. Approximately 5,400 clones from each library were sequenced from both the 5' and 3' directions using the Sanger method. In addition, double-stranded cDNA was prepared from random-primed polyA RNA purified from embryos, second-instar larvae, adult males, and adult females. These four cDNA samples were used for 454 pyrosequencing that produced approximately 300,000 independent sequences. Sequences were assembled into a database of assembled contigs and singletons and used to search public protein databases and annotate the sequences. The full database consists of 6,076 contigs and 58,221 singletons assembled from both the traditional expressed sequence tag (EST) and 454 sequences. Annotation of the data led to the identification of several gene coding regions with possible roles in sex determination in the screwworm. This database will facilitate the design of microarray and other experiments to study screwworm gene expression on a larger scale than previously possible.


Assuntos
Dípteros/genética , Etiquetas de Sequências Expressas , Processos de Determinação Sexual , Sequência de Aminoácidos , Animais , Bases de Dados Genéticas , Feminino , Genes de Insetos , Masculino , Dados de Sequência Molecular
4.
Insect Mol Biol ; 18(2): 129-54, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19320755

RESUMO

Ticks infest a wide range of hosts while bypassing their immune, inflammatory and haemostatic responses during their extended feeding, which may last for more than two weeks. Here, we present a transcriptome analysis of 3868 expressed sequence tags (ESTs) from three cDNA libraries generated from the salivary glands of adult female Ambyomma americanum ticks at different stages of feeding. We applied a normalization step for one library, significantly decreasing the abundance of mitochondrial sequences amongst the 2292 sequences from the normalized library. Our ESTs include homologues that may modulate haemostatic, immune and inflammatory responses of the hosts. Other ESTs probably represent important components of the highly efficient secretory pathways for salivary proteins and concomitantly transmitted pathogens.


Assuntos
Perfilação da Expressão Gênica , Ixodidae/genética , Glândulas Salivares/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , DNA Mitocondrial/genética , Feminino , Biblioteca Gênica , Proteínas de Insetos/química , Proteínas de Insetos/genética , Masculino , Dados de Sequência Molecular , Inibidores de Proteases/química , Alinhamento de Sequência , Análise de Sequência de DNA
5.
Genomics ; 89(3): 429-38, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17210241

RESUMO

Kallikreins belong to a family of serine proteases that are widespread throughout living organisms, expressed in diverse tissue-specific patterns, and known to have highly diverse physiological functions. The 15 human and 24 mouse kallikreins have been implicated in pathophysiology of brain, kidney, and respiratory and reproductive systems and often are used as cancer biomarkers. To better elucidate the structure and evolutionary origin of this important gene family in the pig, we have constructed a contiguous BAC clone-derived physical map of the porcine kallikrein gene region and have fully sequenced a BAC clone containing 13 kallikrein genes, 11 of which are novel. Radiation hybrid mapping assigns this kallikrein-gene-rich region to porcine chromosome 6. Phylogenetic and percent identity plot-based analyses revealed strong structure and order conservation of kallikreins among four mammalian species. Reverse transcriptase-polymerase chain reaction-based expression analysis of porcine kallikreins showed a complex expression pattern across different tissues with the thymus being the only tissue expressing all 13 kallikrein genes. [The sequence data described in this paper has been submitted to GenBank under Accession No. AC149292].


Assuntos
Expressão Gênica , Calicreínas/genética , Mapeamento Físico do Cromossomo , Suínos/genética , Animais , Cromossomos Artificiais Bacterianos , Humanos , Dados de Sequência Molecular , Especificidade de Órgãos , Filogenia
6.
Pharmacogenomics J ; 6(2): 105-14, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16314882

RESUMO

The four members of the human CYP3A subfamily play important roles in the clearance of xenobiotics, hormones, and environmental compounds. Many SNPs at the CYP3A locus have been characterized, with several showing large allele frequency differences across populations. In addition to the effects of CYP3A SNPs on drug metabolism, recent studies have highlighted the potential for CYP3A variation in susceptibility to several common phenotypes, including hypertension and cancer. We previously showed that the CYP3A4 and CYP3A5 genes have a strong haplotype structure at varying frequencies across ethnic groups. Here, we extend our re-sequencing survey to the remaining CYP3A genes in the same cluster, CYP3A7 and CYP3A43. Our study identified a large number of SNPs in coding and conserved noncoding sequences, several of which are common. The combined data set allows us to investigate patterns of sequence variation and linkage disequilibrium at the entire CYP3A locus for use in future association studies.


Assuntos
Sistema Enzimático do Citocromo P-450/genética , Haplótipos , Desequilíbrio de Ligação , Família Multigênica , Polimorfismo de Nucleotídeo Único , Negro ou Afro-Americano/genética , Animais , Sequência de Bases , Citocromo P-450 CYP3A , Frequência do Gene , Humanos , Dados de Sequência Molecular , Análise de Sequência de DNA , População Branca/genética
7.
Pharmacogenomics J ; 6(1): 52-62, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16314881

RESUMO

Common polymorphisms within the human UGT1A gene locus are associated with irinotecan and tranilast toxicity. To uncover additional functional variation across this gene cluster, cross-species sequence comparisons were performed. Evolutionarily conserved segments (a total of 47.1 kb) were re-sequenced in 24 African-American, 24 European-American, and 24 Asian individuals, and 381 segregating sites (including 123 singletons) were identified. Highly conserved coding sites were less likely to be polymorphic than diverged sites (P<0.0001) but this pattern was not observed at non-coding sites (P=0.1025). Among coding variants, the distribution of those computationally predicted to affect function was skewed toward low frequencies. Some alleles occurred at similar frequencies in each population; others had wide disparities. Although strong linkage disequilibrium was detected among the hepatically expressed genes, the degree of linkage disequilibrium varied among populations. These results suggest that rare functional gene variants and inter-population variability must be considered in the interpretation of association studies between UGT1A and drug metabolism/toxicity phenotypes.


Assuntos
Variação Genética , Glucuronosiltransferase/genética , Família Multigênica , Animais , Povo Asiático/genética , Sequência de Bases , População Negra/genética , Cães , Frequência do Gene , Humanos , Camundongos , Dados de Sequência Molecular , Papio , Ratos , Alinhamento de Sequência , Especificidade da Espécie , População Branca/genética
8.
Appl Environ Microbiol ; 71(12): 7716-23, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16332744

RESUMO

Cucurbit yellow vine disease (CYVD) is caused by disease-associated Serratia marcescens strains that have phenotypes significantly different from those of nonphytopathogenic strains. To identify the genetic differences responsible for pathogenicity-related phenotypes, we used a suppressive subtractive hybridization (SSH) strategy. S. marcescens strain Z01-A, isolated from CYVD-affected zucchini, was used as the tester, whereas rice endophytic S. marcescens strain R02-A (IRBG 502) was used as the driver. SSH revealed 48 sequences, ranging from 200 to 700 bp, that were present in Z01-A but absent in R02-A. Sequence analysis showed that a large proportion of these sequences resembled genes involved in synthesis of surface structures. By construction of a fosmid library, followed by colony hybridization, selection, and DNA sequencing, a phage gene cluster and a genome island containing a fimbrial-gene cluster were identified. Arrayed dot hybridization showed that the conservation of subtracted sequences among CYVD pathogenic and nonpathogenic S. marcescens strains varied. Thirty-four sequences were present only in pathogenic strains. Primers were designed based on one Z01-A-specific sequence, A79, and used in a multiplex PCR to discriminate between S. marcescens strains causing CYVD and those from other ecological niches.


Assuntos
Plantas/microbiologia , Serratia marcescens/genética , Sequência de Bases , Cromossomos Bacterianos , Primers do DNA , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Dados de Sequência Molecular , Hibridização de Ácido Nucleico/métodos , Doenças das Plantas/microbiologia , Reação em Cadeia da Polimerase/métodos , Mapeamento por Restrição , Serratia marcescens/patogenicidade
10.
Am J Hum Genet ; 75(6): 1059-69, 2004 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15492926

RESUMO

Members of the cytochrome P450 3A subfamily catalyze the metabolism of endogenous substrates, environmental carcinogens, and clinically important exogenous compounds, such as prescription drugs and therapeutic agents. In particular, the CYP3A4 and CYP3A5 genes play an especially important role in pharmacogenetics, since they metabolize >50% of the drugs on the market. However, known genetic variants at these two loci are not sufficient to account for the observed phenotypic variability in drug response. We used a comparative genomics approach to identify conserved coding and noncoding regions at these genes and resequenced them in three ethnically diverse human populations. We show that remarkable interpopulation differences exist with regard to frequency spectrum and haplotype structure. The non-African samples are characterized by a marked excess of rare variants and the presence of a homogeneous group of long-range haplotypes at high frequency. The CYP3A5*1/*3 polymorphism, which is likely to influence salt and water retention and risk for salt-sensitive hypertension, was genotyped in >1,000 individuals from 52 worldwide population samples. The results reveal an unusual geographic pattern whereby the CYP3A5*3 frequency shows extreme variation across human populations and is significantly correlated with distance from the equator. Furthermore, we show that an unlinked variant, AGT M235T, previously implicated in hypertension and pre-eclampsia, exhibits a similar geographic distribution and is significantly correlated in frequency with CYP3A5*1/*3. Taken together, these results suggest that variants that influence salt homeostasis were the targets of a shared selective pressure that resulted from an environmental variable correlated with latitude.


Assuntos
Sistema Enzimático do Citocromo P-450/genética , Evolução Molecular , Variação Genética , Equilíbrio Hidroeletrolítico/genética , Negro ou Afro-Americano/genética , Asiático/genética , Sequência de Bases , Sítios de Ligação , Sequência Conservada/genética , Citocromo P-450 CYP3A , Primers do DNA , Frequência do Gene , Genômica/métodos , Geografia , Haplótipos/genética , Humanos , Los Angeles , Dados de Sequência Molecular , Polimorfismo de Nucleotídeo Único/genética , Análise de Sequência de DNA , Cloreto de Sódio/metabolismo , Fatores de Transcrição/metabolismo , População Branca/genética
11.
Mol Genet Genomics ; 271(3): 325-38, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15024644

RESUMO

Spiroplasma kunkelii is a cell wall-free, helical, and motile mycoplasma-like organism that causes corn stunt disease in maize. The bacterium has a compact genome with a gene set approaching the minimal complement necessary for cellular life and pathogenesis. A set of 21 ATP-binding cassette (ABC) domains was identified during the annotation of a draft S. kunkelii genome sequence. These 21 ABC domains are present in 18 predicted proteins, and are components of 16 functional systems, which account for 5% of the protein coding capacity of the S. kunkelii genome. Of the 16 systems, 11 are membrane-bound transporters, and two are cytosolic systems involved in DNA repair and the oxidative stress response; the genes for the remaining three hypothetical systems harbor nonsense and/or frameshift mutations, so their functional status is doubtful. Assembly of the 11 multicomponent transporters, and comparisons with other known systems permitted functional predictions for the S. kunkelii ABC transporter systems. These transporters convey a wide variety of substrates, and are critical for nutrient uptake, multidrug resistance, and perhaps virulence. Our findings provide a framework for functional characterization of the ABC systems in S. kunkelii.


Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Trifosfato de Adenosina/metabolismo , Proteínas de Bactérias/genética , Genes Bacterianos , Spiroplasma/genética , Transportadores de Cassetes de Ligação de ATP/química , Transportadores de Cassetes de Ligação de ATP/metabolismo , Proteínas de Bactérias/metabolismo , Sítios de Ligação , Replicação do DNA , Genoma Bacteriano , Dados de Sequência Molecular , Filogenia , Doenças das Plantas/microbiologia , Estrutura Terciária de Proteína , Zea mays/microbiologia
12.
Mol Genet Genomics ; 269(5): 592-602, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12845528

RESUMO

Spiroplasma kunkelii, the causative agent of corn stunt disease in maize (Zea maysL.), is a helical, cell wall-less prokaryote assigned to the class Mollicutes. As part of a project to sequence the entire S. kunkelii genome, we analyzed an 85-kb DNA segment from the pathogenic strain CR2-3x. This genome segment contains 101 ORFs and two tRNA genes. The majority of the ORFs code for predicted proteins that can be assigned to respective clusters of orthologous groups (COGs). These COGs cover diverse functional categories including genetic information storage and processing, cellular processes, and metabolism. The most notable gene cluster in this genome segment is a super-operon capable of encoding 24 ribosomal proteins. The organization of genes in this operon reflects the unique evolutionary position of the spiroplasma. Gene duplications, domain rearrangements, and frameshift mutations in the segment are interpreted as indicators of phase variation in the spiroplasma. To our knowledge, this is the first analysis of a large genome segment from a plant pathogenic spiroplasma.


Assuntos
Genes Bacterianos , Genoma Bacteriano , Mapeamento Físico do Cromossomo , Spiroplasma/genética , Sequência de Bases , Transporte Biológico , Metabolismo dos Carboidratos , Segregação de Cromossomos , Códon , Replicação do DNA , Metabolismo Energético , Duplicação Gênica , Regulação Bacteriana da Expressão Gênica , Dados de Sequência Molecular , Nucleotídeos/metabolismo , Proteínas Ribossômicas/genética , Alinhamento de Sequência , Análise de Sequência de DNA
14.
Mol Biol Evol ; 20(9): 1463-79, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12777517

RESUMO

Despite considerable advances in sequencing of the human genome over the past few years, the organization and evolution of human pericentromeric regions have been difficult to resolve. This is due, in part, to the presence of large, complex blocks of duplicated genomic sequence at the boundary between centromeric satellite and unique euchromatic DNA. Here, we report the identification and characterization of an approximately 49-kb repeat sequence that exists in more than 40 copies within the human genome. This repeat is specific to highly duplicated pericentromeric regions with multiple copies distributed in an interspersed fashion among a subset of human chromosomes. Using this interspersed repeat (termed PIR4) as a marker of pericentromeric DNA, we recovered and sequence-tagged 3 Mb of pericentromeric DNA from a variety of human chromosomes as well as nonhuman primate genomes. A global evolutionary reconstruction of the dispersal of PIR4 sequence and analysis of flanking sequence supports a model in which pericentromeric duplications initiated before the separation of the great ape species (>12 MYA). Further, analyses of this duplication and associated flanking duplications narrow the major burst of pericentromeric duplication activity to a time just before the divergence of the African great ape and human species (5 to 7 MYA). These recent duplication exchange events substantially restructured the pericentromeric regions of hominoid chromosomes and created an architecture where large blocks of sequence are shared among nonhomologous chromosomes. This report provides the first global view of the series of historical events that have reshaped human pericentromeric regions over recent evolutionary time.


Assuntos
Centrômero/genética , Duplicação Gênica , Genoma Humano , Hominidae/genética , Sequências Repetitivas de Ácido Nucleico/genética , Animais , Cromossomos Humanos , Evolução Molecular , Variação Genética , Humanos , Hibridização in Situ Fluorescente , Dados de Sequência Molecular , Filogenia , Mapeamento Físico do Cromossomo , Primatas
16.
Cytogenet Genome Res ; 102(1-4): 89-94, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14970685

RESUMO

1,144 sheep belonging to 21 breeds and known crosses were sequence analyzed for polymorphisms in the ovine PRNP gene. Genotype and allele frequencies of polymorphisms in PRNP known to confer resistance to scrapie, a fatal neurodegenerative disease of sheep, are reported. Known polymorphisms at codons 136 (A/V), 154 (H/R) and 171 (Q/R/H/K) were identified. The frequency of the 171R allele known to confer resistance to type C scrapie was 53.8% and the frequency of the 136A allele known to influence the resistance to type A scrapie was 96.01%. In addition, we report the identification of five new polymorphisms at codons 143 (H/R), 167 (R/S), 180 (H/Y), 195 (T/S) and 196 (T/S). We also report the identification of a novel allele (S/R) at codon 138.


Assuntos
Frequência do Gene/genética , Variação Genética/genética , Polimorfismo Genético/genética , Proteínas PrPC/genética , Scrapie/genética , Carneiro Doméstico/genética , Animais , Códon/genética , Feminino , Masculino , Oklahoma
17.
J Interferon Cytokine Res ; 22(6): 729-37, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12162885

RESUMO

The murine 200 family proteins p202a, p202b, and p204, and also RNA-dependent protein kinase (PKR) are inducible by interferons (IFNs). p202a, p202b, and p204 modulate the activity of a large variety of transcription factors and also are involved in muscle differentiation. PKR is a multifunctional serine/threonine kinase, which is involved in antiviral defense and cell growth control and in the response to various stress signals. We reported earlier that the level of p204 increases during cultured C2C12 myoblast differentiation to myotubes in consequence of transactivation by the skeletal muscle-specific MyoD protein. The levels of p202a, p202b, and PKR also increase during the differentiation. We report here that these increased protein levels also are due to the transactivation of their genes by MyoD. This is made possible by the occurrence in each of these genes of at least six E boxes, which are recognition sites for MyoD. We also show that the distribution of the p204, p202a, p202b, and PKR proteins in five tissues of adult C129 mice is the same in wild-type mice and mice lacking the IFN-alpha, IFN-beta, and IFN-gamma receptors. This indicates that the synthesis and distribution of these proteins in uninfected adult mice are not affected by endogenous IFNs.


Assuntos
Proteínas de Transporte/genética , Diferenciação Celular , Interferons , Peptídeos e Proteínas de Sinalização Intracelular , Proteína MyoD/metabolismo , Mioblastos/metabolismo , Fosfoproteínas/genética , Ativação Transcricional , eIF-2 Quinase/genética , Animais , Sequência de Bases , Proteínas de Transporte/biossíntese , Linhagem Celular , Expressão Gênica , Camundongos , Camundongos Knockout , Dados de Sequência Molecular , Mioblastos/citologia , Fosfoproteínas/biossíntese , Sequências Reguladoras de Ácido Nucleico , Distribuição Tecidual , Transcrição Gênica , eIF-2 Quinase/biossíntese
18.
Gene ; 289(1-2): 109-18, 2002 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-12036589

RESUMO

The genomes of the three temperate bacteriophages contained in the chromosome of Staphylococcus aureus 8325 have been extracted from the sequence database and analyzed. phi 11, phi 12 and phi 13 are members of the same lytic group but different serogroups and consequently co-habitate the same host cell. Their genomes are approximately 42 kb to 45 kb and contain about 90 ORFs of at least 50 codons. Of these, about 50 have similarities to known genes or to genes of other staphylococcal phages. Each of the phages clusters within a homology group that share large regions of sequence identity while intergroup homology is comparatively low. The arrangement of genes on the chromosomes of the three phages is similar and consistent with current modular theory of phage gene organization. The replicated genomes appear to be packaged by different mechanisms. Phage phi 11 and phi 12 have been found to contain sequences consistent with pac-site phages while phi 13 has sequences consistent with cos-site phages. The attBsite for phi 11 is located in an intergenic region of the S. aureus chromosome while phi 12 and phi 13 integrate into specific genes. The phi 12 att-site is within an unknown gene, but the phi 13 att-site is within the beta-toxin gene. In contrast to the other two phages, phi 13 also introduces the staphylokinase gene (sak) and a second gene related to expression of fib.


Assuntos
Genoma Viral , Fagos de Staphylococcus/genética , Composição de Bases , DNA Circular/genética , DNA Viral/genética , Bases de Dados de Ácidos Nucleicos , Fases de Leitura Aberta/genética , Filogenia , Mapeamento por Restrição , Especificidade da Espécie , Staphylococcus aureus/virologia
19.
Cytogenet Genome Res ; 98(4): 245-8, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12826747

RESUMO

The human TCF12 gene, mapping to 15q21, encodes the helix-loop-helix transcription factor 4 (HTF4). A detailed analysis of this genomic region established the organization of the TCF12 gene. The gene includes 21 exons and is significantly larger than an average human gene. Preceding the second exon, two alternative acceptor sites for mRNA splicing yield two distinguishable transcripts (HTF4a and HTF4b) which differ in their 5' untranslated region but share identical coding sequences. Differential utilization of exon 15 in the TCF12 gene may reflect a mechanism producing a cell-type-specific protein (HTF4c). In addition, intron 5 in the TCF12 gene corresponds to the region involved in a translocation, t(9;15)(q22;q21), that results in a form of extraskeletal myxoid chondrosarcoma.


Assuntos
Proteínas de Ligação a DNA/genética , Splicing de RNA/genética , Fatores de Transcrição/genética , Região 5'-Flanqueadora/genética , Sequência de Aminoácidos , Sequência de Bases , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Neoplasias Ósseas/genética , Condrossarcoma/genética , Cromossomos Humanos Par 15 , Proteínas de Ligação a DNA/química , Éxons/genética , Humanos , Isomerismo , Dados de Sequência Molecular , RNA Mensageiro/genética , Fatores de Transcrição/química , Translocação Genética
20.
Genomics ; 78(1-2): 30-7, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11707070

RESUMO

Hermansky-Pudlak syndrome (HPS) is a group of human disorders of organelle biogenesis characterized by defective synthesis of melanosomes, lysosomes, and platelet dense granules. In the mouse, at least 15 loci are associated with mutant phenotypes similar to human HPS. We have identified the gene mutated in cocoa (coa) mice, which is associated with an HPS-like mutant phenotype and thus represents a strong candidate for human HPS. Analysis of coa-mutant mice and cultured coa-mutant mouse melanocytes indicates that the normal coa gene product is involved in early stages of melanosome biogenesis and maturation.


Assuntos
Proteínas de Membrana/genética , Organelas/metabolismo , Alelos , Sequência de Aminoácidos , Animais , Sequência de Bases , Northern Blotting , Células Cultivadas , Mapeamento Cromossômico , Clonagem Molecular , DNA/química , DNA/genética , Feminino , Expressão Gênica , Genes/genética , Cor de Cabelo/genética , Heterozigoto , Homozigoto , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Masculino , Melanócitos/citologia , Melanócitos/metabolismo , Melanócitos/ultraestrutura , Melanossomas/metabolismo , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Microscopia Eletrônica , Dados de Sequência Molecular , Mutação , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Distribuição Tecidual
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