RESUMO
The family Adenoviridae includes non-enveloped viruses with linear dsDNA genomes of 25-48 kb and medium-sized icosahedral capsids. Adenoviruses have been discovered in vertebrates from fish to humans. The family is divided into six genera, each of which is more common in certain animal groups. The outcome of infection may vary from subclinical to lethal disease. This is a summary of the ICTV Report on the family Adenoviridae, which is available at ictv.global/report/adenoviridae.
Assuntos
Adenoviridae , Vertebrados , Animais , Peixes , Genoma Viral , Vírion , Replicação ViralRESUMO
Species Human mastadenovirus E (HAdV-E) comprises several simian types and a single human type: HAdV-E4, a respiratory and ocular pathogen. RFLP analysis for the characterization of intratypic genetic variability has previously distinguished two HAdV-E4 clusters: prototype (p)-like and a-like. Our analysis of whole genome sequences confirmed two distinct lineages, which we refer to as phylogroups (PGs). PGs I and II comprise the p- and a-like genomes, respectively, and differ significantly in their G + C content (57.7% ± 0.013 vs 56.3% ± 0.015). Sequence differences distinguishing the two clades map to several regions of the genome including E3 and ITR. Bayesian analyses showed that the two phylogroups diverged approximately 602 years before the present. A relatively faster evolutionary rate was identified for PG II. Our data provide a rationale for the incorporation of phylogroup identity to HAdV-E4 strain designation to reflect the identified unique genetic characteristics that distinguish PGs I and II.
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Infecções por Adenovirus Humanos/virologia , Adenovírus Humanos/genética , Genoma Viral , Filogenia , Adenovírus Humanos/classificação , Adenovírus Humanos/isolamento & purificação , Composição de Bases , Sequência de Bases , Evolução Molecular , Genômica , Humanos , Recombinação Genética , Proteínas Virais/genéticaRESUMO
BACKGROUND: Retroposition, one of the processes of copying the genetic material, is an important RNA-mediated mechanism leading to the emergence of new genes. Because the transcription controlling segments are usually not copied to the new location in this mechanism, the duplicated gene copies (retrocopies) become pseudogenized. However, few can still survive, e.g. by recruiting novel regulatory elements from the region of insertion. Subsequently, these duplicated genes can contribute to the formation of lineage-specific traits and phenotypic diversity. Despite the numerous studies of the functional retrocopies (retrogenes) in animals and plants, very little is known about their presence in green algae, including morphologically diverse species. The current availability of the genomes of both uni- and multicellular algae provides a good opportunity to conduct a genome-wide investigation in order to fill the knowledge gap in retroposition phenomenon in this lineage. RESULTS: Here we present a comparative genomic analysis of uni- and multicellular algae, Chlamydomonas reinhardtii and Volvox carteri, respectively, to explore their retrogene complements. By adopting a computational approach, we identified 141 retrogene candidates in total in both genomes, with their fraction being significantly higher in the multicellular Volvox. Majority of the retrogene candidates showed signatures of functional constraints, thus indicating their functionality. Detailed analyses of the identified retrogene candidates, their parental genes, and homologs of both, revealed that most of the retrogene candidates were derived from ancient retroposition events in the common ancestor of the two algae and that the parental genes were subsequently lost from the respective lineages, making many retrogenes 'orphan'. CONCLUSION: We revealed that the genomes of the green algae have maintained many possibly functional retrogenes in spite of experiencing various molecular evolutionary events during a long evolutionary time after the retroposition events. Our first report about the retrogene set in the green algae provides a good foundation for any future investigation of the repertoire of retrogenes and facilitates the assessment of the evolutionary impact of retroposition on diverse morphological traits in this lineage. REVIEWERS: This article was reviewed by William Martin and Piotr Zielenkiewicz.
Assuntos
Proteínas de Algas/genética , Chlamydomonas reinhardtii/genética , Genoma de Planta , Proteínas de Plantas/genética , Retroelementos , Volvox/genética , Proteínas de Algas/metabolismo , Proteínas de Plantas/metabolismoRESUMO
UNLABELLED: Human mastadenovirus D (HAdV-D) is exceptionally rich in type among the seven human adenovirus species. This feature is attributed to frequent intertypic recombination events that have reshuffled orthologous genomic regions between different HAdV-D types. However, this trend appears to be paradoxical, as it has been demonstrated that the replacement of some of the interacting proteins for a specific function with other orthologues causes malfunction, indicating that intertypic recombination events may be deleterious. In order to understand why the paradoxical trend has been possible in HAdV-D evolution, we conducted an interregional coevolution analysis between different genomic regions of 45 different HAdV-D types and found that ca. 70% of the genome has coevolved, even though these are fragmented into several pieces via short intertypic recombination hot spot regions. Since it is statistically and biologically unlikely that all of the coevolving fragments have synchronously recombined between different genomes, it is probable that these regions have stayed in their original genomes during evolution as a platform for frequent intertypic recombination events in limited regions. It is also unlikely that the same genomic regions have remained almost untouched during frequent recombination events, independently, in all different types, by chance. In addition, the coevolving regions contain the coding regions of physically interacting proteins for important functions. Therefore, the coevolution of these regions should be attributed at least in part to natural selection due to common biological constraints operating on all types, including protein-protein interactions for essential functions. Our results predict additional unknown protein interactions. IMPORTANCE: Human mastadenovirus D, an exceptionally type-rich human adenovirus species and causative agent of different diseases in a wide variety of tissues, including that of ocular region and digestive tract, as well as an opportunistic infection in immunocompromised patients, is known to have highly diverged through frequent intertypic recombination events; however, it has also been demonstrated that the replacement of a component protein of a multiprotein system with a homologous protein causes malfunction. The present study solved this apparent paradox by looking at which genomic parts have coevolved using a newly developed method. The results revealed that intertypic recombination events have occurred in limited genomic regions and been avoided in the genomic regions encoding proteins that physically interact for a given function. This approach detects purifying selection against recombination events causing the replacement of partial components of multiprotein systems and therefore predicts physical and functional interactions between different proteins and/or genomic elements.
Assuntos
Evolução Molecular , Variação Genética , Genoma Viral , Mastadenovirus/classificação , Mastadenovirus/genética , Humanos , Ligação Proteica , Recombinação Genética , Seleção Genética , Proteínas Virais/genética , Proteínas Virais/metabolismoRESUMO
OBJECTIVES: Do antimicrobial stewardship programs (ASPs) contribute to reduction of antimicrobial therapy costs in Japanese community hospitals? To answer this health economic question, a before-after comparative two-year trial in a community hospital in the country was designed. METHODS: The study was conducted at National Hospital Organization Tochigi Medical Center, a community hospital with 429 beds. We compared six-month period before-ASP (January 2010 to June 2010) and 24-month period after ASP (July 2010 to June 2012) in primary and secondary outcome measures. Three medical doctors, three pharmacists and two microbiology technologists participate in the ASPs. The team then provided recommendations based on the supplemental elements to primary physicians who prescribed injectable antimicrobials. Prospective audit with intervention and feedback was applied in the core strategy while dose optimization, de-escalation and recommendations for alternate agents and blood cultures were applied in the supplemental elements. The primary outcome was measured by the antimicrobial therapy costs (USD per 1,000 patient-days), while the secondary outcomes included the amount of antimicrobials used (defined daily doses per 1,000 patient-days), sensitivity rates (%) of Pseudomonas aeruginosa (P. aeruginosa) to Meropenem (MEPM), Ciprofloxacin (CPFX) and Amikacin (AMK), length of stay (days) and detection rates (per 1,000 patient-day) of methicillin-resistant Staphylococcus aureus (MRSA) and extended spectrum beta-lactamase-producing organisms (ESBLs) through blood cultures. RESULTS: In the study, recommendations were made for 465 cases out of 1,427 cases subject to the core strategy, and recommendations for 251 cases (54.0%) were accepted. After ASP, the antimicrobial therapy costs decreased by 25.8% (P = 0.005) from those before ASP. Among the secondary outcomes, significant changes were observed in the amount of aminoglycosides used, which decreased by 80.0% (P < 0.001) and the detection rate of MRSA, which decreased by 48.3% (P < 0.001). CONCLUSIONS: The study suggested the possibility that ASPs contributed to the reduction of the antimicrobial therapy costs in a community hospital with 429 beds.
RESUMO
Recently, new genotypes of human adenoviruses (HAdVs) have been reported and many of them have been found to be recombinant forms of different known types of HAdV species D (HAdV-D). The objective of this study was to document the evolutionary features of a novel isolate (HAdV_Chiba_E086/2012) obtained from the eye swab of a patient with conjunctivitis in Japan. Viral DNA was extracted from the isolate to sequence the whole genome by the Sanger method and aligned with available genome sequences of HAdV-Ds. The phylogenetic trees of the nucleotide sequences of the penton base, hexon, and fiber genes and the E3 region showed that HAdV_Chiba_E086/2012 is closest to HAdV genotype 65 (HAdV-GT65), HAdV-48, HAdV-GT60 and HAdV-22 at 98%, 99%, 95% and 98% identity, respectively, suggesting that this isolate is a novel recombinant form to be designated as P65H48F60. Further phylogenetic and recombination analyses of the genome alignment of the new isolate implied that nested recombination events involving HAdV-GT59, GT65, 48, GT60, 22, and some ancestral lineages or their close relatives have shaped its genome. These results showed that HAdV_Chiba_E086/2012 is the first HAdV-48-related HAdV found in Japan, which has the most complicated evolutionary history among the known HAdVs so far.
Assuntos
Infecções por Adenovirus Humanos/virologia , Adenovírus Humanos/genética , Adenovírus Humanos/classificação , Adenovírus Humanos/isolamento & purificação , DNA Viral/análise , DNA Viral/genética , Feminino , Humanos , Japão , Pessoa de Meia-Idade , Filogenia , Recombinação Genética , Análise de Sequência de DNARESUMO
Human adenovirus species D (HAdV-D), which is composed of clinically and epidemiologically important pathogens worldwide, contains more taxonomic "types" than any other species of the genus Mastadenovirus, although the mechanisms accounting for the high level of diversity remain to be disclosed. Recent studies of known and new types of HAdV-D have indicated that intertypic recombination between distant types contributes to the increasing diversity of the species. However, such findings raise the question as to how homologous recombination events occur between diversified types since homologous recombination is suppressed as nucleotide sequences diverge. In order to address this question, we investigated the distribution of the recombination boundaries in comparison with the landscape of intergenomic sequence conservation assessed according to the synonymous substitution rate (dS). The results revealed that specific genomic segments are conserved between even the most distantly related genomes; we call these segments "universally conserved segments" (UCSs). These findings suggest that UCSs facilitate homologous recombination, resulting in intergenomic segmental exchanges of UCS-flanking genomic regions as recombination modules. With the aid of such a mechanism, the haploid genomes of HAdV-Ds may have been reshuffled, resulting in chimeric genomes out of diversified repertoires in the HAdV-D population analogous to the MHC region reshuffled via crossing over in vertebrates. In addition, some HAdVs with chimeric genomes may have had the opportunity to avoid host immune responses thereby causing epidemics.
Assuntos
Adenoviridae/genética , Genoma Viral , Recombinação Homóloga , Filogenia , Alinhamento de SequênciaRESUMO
Human adenovirus (HAdV) causing epidemic keratoconjunctivitis is limited to D and E species. Recent progress in bioinformatics revealed that these viruses attach to the host with fibers, infiltrate the host cells via RGD (Arg-Gly-Asp) motif of penton base, and reveal their serological reaction by hexons. Loops 1 and 2 are the variable regions of each hexon. The possibility that a novel adenovirus later named HAdV-52 was transmitted over the wall of species' from monkeys to humans was reported. The recombination of the above three hot spots introduces novel types such as HAdV-53, -54, and -56. Boinformatics may provide rapid genotyping in nosocomial infection, predicting future epidemics, and an estimate of the therapeutic target molecules in the near future.
Assuntos
Adenovírus Humanos/genética , Biologia Computacional , Infecção Hospitalar/virologia , Adenovírus Humanos/química , Animais , Sequência de Bases , Haplorrinos , Humanos , Ceratoconjuntivite Infecciosa/virologiaAssuntos
Adenovírus Humanos/genética , Adenovírus Humanos/isolamento & purificação , Bancos de Espécimes Biológicos/normas , Preservação Biológica/normas , Análise por Conglomerados , DNA Viral/química , DNA Viral/genética , Genoma Viral , Humanos , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNA , Estados UnidosRESUMO
We sequenced the genome of Theileria orientalis, a tick-borne apicomplexan protozoan parasite of cattle. The focus of this study was a comparative genome analysis of T. orientalis relative to other highly pathogenic Theileria species, T. parva and T. annulata. T. parva and T. annulata induce transformation of infected cells of lymphocyte or macrophage/monocyte lineages; in contrast, T. orientalis does not induce uncontrolled proliferation of infected leukocytes and multiplies predominantly within infected erythrocytes. While synteny across homologous chromosomes of the three Theileria species was found to be well conserved overall, subtelomeric structures were found to differ substantially, as T. orientalis lacks the large tandemly arrayed subtelomere-encoded variable secreted protein-encoding gene family. Moreover, expansion of particular gene families by gene duplication was found in the genomes of the two transforming Theileria species, most notably, the TashAT/TpHN and Tar/Tpr gene families. Gene families that are present only in T. parva and T. annulata and not in T. orientalis, Babesia bovis, or Plasmodium were also identified. Identification of differences between the genome sequences of Theileria species with different abilities to transform and immortalize bovine leukocytes will provide insight into proteins and mechanisms that have evolved to induce and regulate this process. The T. orientalis genome database is available at http://totdb.czc.hokudai.ac.jp/.
Assuntos
Genoma de Protozoário , Theileria/genética , Theileria/patogenicidade , Fatores de Virulência/genética , Animais , Bovinos , Proliferação de Células , Leucócitos/parasitologia , SinteniaRESUMO
Brachyury, a member of the T-box transcription family, has been suggested to be essential for morphogenetic movements in various processes of animal development. However, little is known about its critical transcriptional targets. In order to identify targets of Brachyury and understand the molecular mechanisms underlying morphogenetic movements, we first searched the genome sequence of Xenopus tropicalis, the only amphibian genomic sequence available, for Brachyury-binding sequences known as T-half sites, and then screened for the ones conserved between vertebrate genomes. We found three genes that have evolutionarily conserved T-half sites in the promoter regions and examined these genes experimentally to determine whether their expressions were regulated by Brachyury, using the animal cap system of Xenopus laevis embryos. Eventually, we obtained evidence that vimentin, encoding an intermediate filament protein, was a potential target of Brachyury. This is the first report to demonstrate that Brachyury might affect the cytoskeletal structure through regulating the expression of an intermediate filament protein, vimentin.
Assuntos
Movimento Celular/genética , Desenvolvimento Embrionário/genética , Proteínas Fetais/genética , Regulação da Expressão Gênica no Desenvolvimento , Proteínas com Domínio T/genética , Vimentina/genética , Animais , Regulação para Baixo , Xenopus/genética , Xenopus laevis/genéticaRESUMO
Human adenovirus type 53 (HAdV-53) has commonly been detected in samples from epidemic keratoconjunctivitis (EKC) patients in Japan since 1996. HAdV-53 is an intermediate virus, containing hexon-chimeric, penton base and fiber structures similar to HAdV-22 and -37, HAdV-37 and HAdV-8, respectively. HAdV-53-like intermediate strains were first isolated from EKC samples in Japan in the 1980s. Here, the complete genome sequences of three such HAdV-53-like intermediate strains (870006C, 880249C and 890357C) and four HAdV-53 strains were determined, and their relationships were analysed. The seven HAdV strains were classified into three groups, 870006C/880249C, 890357C and the four HAdV-53 strains, on the basis of phylogenetic analyses of the partial and complete genome sequences. HAdV strains within the same group showed the highest nucleotide identities (99.87-100.00â%). Like HAdV-53, the hexon loop 1 and 2 regions of 870006C, 880249C and 890357C showed the highest identity with HAdV-22. However, these strains did not show a hexon-chimeric structure similar to HAdV-22 and -37, or a penton base similar to HAdV-37. The fiber genes of 870006C and 880249C were identical to that of HAdV-37, but not HAdV-8. Thus, the three intermediate HAdVs isolated in the 1980s were similar to each other but not to HAdV-53. The recombination breakpoints were inferred by the Recombination Detection Program (rdp) using whole-genome sequences of these seven HAdV and of 12 HAdV-D strains from GenBank. HAdV-53 may have evolved from intermediate HAdVs circulating in the 1980s, and from HAdV-8, -22 and -37, by recombination of sections cut at the putative breakpoints.
Assuntos
Infecções por Adenovirus Humanos/virologia , Adenovírus Humanos/genética , Genoma Viral , Ceratoconjuntivite/virologia , Recombinação Genética , Infecções por Adenovirus Humanos/epidemiologia , Adenovírus Humanos/classificação , Adenovírus Humanos/isolamento & purificação , Humanos , Japão/epidemiologia , Ceratoconjuntivite/epidemiologia , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNARESUMO
For 4 months from September 2008, 102 conjunctival swab specimens were collected for surveillance purposes from patients across Japan suspected of having epidemic keratoconjunctivitis (EKC). Human adenovirus (HAdV) DNA was detected in 61 samples by PCR, though the HAdV type for 6 of the PCR-positive samples could not be determined by phylogenetic analysis using a partial hexon gene sequence. Moreover, for 2 months from January 2009, HAdV strains with identical sequences were isolated from five conjunctival swab samples obtained from EKC patients in five different regions of Japan. For the analyses of the 11 samples mentioned above, we determined the nucleotide sequences of the entire penton base, hexon, and fiber genes and early 3 (E3) region, which are variable regions among HAdV types, and compared them to those of other HAdV species D strains. The nucleotide sequences of loops 1 and 2 in the hexons of all 11 samples showed high degrees of identity with those of the HAdV type 15 (HAdV-15) and HAdV-29 prototype strains. However, the fiber gene and E3 region sequences showed high degrees of identity with those of HAdV-9, and the penton base gene sequence showed a high degree of identity with the penton base gene sequences of HAdV-9 and -26. Moreover, the complete genome sequence of the 2307-S strain, which was isolated by viral culture from 1 of the 11 samples, was determined. The 2307-S strain was a recombinant HAdV between HAdV-9, -15, -26, -29, and/or another HAdV type; however, the recombination sites in the genome were not obvious. We propose that this virus is a novel intertypic recombinant, HAdV-15/29/H9, and may be an etiological agent of EKC.
Assuntos
Infecções por Adenoviridae/epidemiologia , Adenovírus Humanos/genética , Adenovírus Humanos/isolamento & purificação , DNA Viral/genética , Genoma Viral , Ceratoconjuntivite/epidemiologia , Infecções por Adenoviridae/virologia , Análise por Conglomerados , DNA Viral/química , Humanos , Japão/epidemiologia , Ceratoconjuntivite/virologia , Epidemiologia Molecular , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNA , Homologia de Sequência , Proteínas Virais/genéticaRESUMO
SUMMARY: Comparative approach is one of the most essential methods for extracting functional and evolutionary information from genomic sequences. So far, a number of sequence comparison tools have been developed, and most are either for on-site use, requiring program installation but providing a wide variety of analyses, or for the online search of user's sequences against given databases on a server. We newly devised an Asynchronous JavaScript and XML (Ajax)-based system for comparative genomic analyses, CGAS, with highly interactive interface within a browser, requiring no software installation. The current version, CGAS version 1, provides functionality for viewing similarity relationships between user's sequences, including a multiple dot plot between sequences with their annotation information. The scrollbar-less 'draggable' interface of CGAS is implemented with Google Maps API version 2. The annotation information associated with the genomic sequences compared is synchronously displayed with the comparison view. The multiple-comparison viewer is one of the unique functionalities of this system to allow the users to compare the differences between different pairs of sequences. In this viewer, the system tells orthologous correspondences between the sequences compared interactively. This web-based tool is platform-independent and will provide biologists having no computational skills with opportunities to analyze their own data without software installation and customization of the computer system. AVAILABILITY AND IMPLEMENTATION: CGAS is available at http://cgas.ist.hokudai.ac.jp/.
Assuntos
Genoma , Genômica/métodos , Software , Hibridização Genômica Comparativa , Internet , Interface Usuário-ComputadorAssuntos
Sequência de Bases/genética , Genoma Humano/genética , Genoma/genética , Pan troglodytes/genética , Análise de Sequência de DNA , Substituição de Aminoácidos/genética , Animais , Evolução Molecular , Frequência do Gene , Humanos , Mutação , Polimorfismo de Nucleotídeo Único , Seleção Genética , Homologia de Sequência do Ácido NucleicoRESUMO
The coalescent process in the human-chimpanzee ancestral population is investigated using a model, which incorporates a certain time period of gene flow during the speciation process. a is a parameter to represent the degree and time of gene flow, and the model is identical to the null model with an instantaneous species split when a=infinity. A maximum likelihood (ML) method is developed to estimate a, and its power and reliability is investigated by coalescent simulations. The ML method is applied to nucleotide divergence data between human and chimpanzee. It is found that the null model with an instantaneous species split explains the data best, and no strong evidence for gene flow is detected. The result is discussed in the view of the mode of speciation. Another ML method is developed to estimate the male-female ratio (alpha) of mutation rate, in which the coalescent process in the ancestral population is taken into account.
Assuntos
Fluxo Gênico , Genética , Modelos Genéticos , Animais , Evolução Biológica , Feminino , Genética Populacional , Humanos , Funções Verossimilhança , Masculino , Modelos Estatísticos , Mutação , Pan troglodytes , Análise de Sequência de DNA , Especificidade da Espécie , Fatores de TempoRESUMO
Indirubin, a purple vegetable dye, is a traditional Chinese medicine for myelocytic leukaemia. Indirubin inhibits cyclin-dependent protein kinases (CDKs) and is present in human urine and serum. When indirubin was present during the neutrophilic differentiation of human myelocytic leukaemia HL-60 cells, it augmented superoxide production triggered by opsonized zymosan (OZ) by the terminally differentiated HL-60 cells. It also augmented the calcium response to OZ stimulation, and HL-60 cell chemotaxis evoked by interleukin-8 (IL-8, CXCL8) and formylpeptide. In addition, indirubin induced marked IL-8 release by the cells during differentiation and the cells differentiated with indirubin had typical neutrophilic properties, deformed nuclei and granules. Use of stable cloned HL-60 cells that contained a reporter vector for monitoring the activity of the transcription factor PU.1, which acts specifically at the stage of promyelocyte differentiation into neutrophils and monocytes, revealed that indirubin has a potent promoting activity on intracellular PU.1. Indirubin enhanced the expression of typical neutrophil proteins, including granulocyte-colony stimulating factor receptor, the beta2-integrin subunit CD18, the NADPH-oxidase subunit p47phox, and the IL-8 receptor CXCR1, all are controlled by PU.1. Indirubin also inhibited CDK2-dependent phosphorylation of retinoblastoma protein during neutrophilic differentiation. These results suggest that indirubin augments the neutrophilic differentiation of human myelocytic leukaemia HL-60 cells through inhibition of CDK2 and activation of PU.1.
Assuntos
Quinases Ciclina-Dependentes/antagonistas & inibidores , Leucemia Mieloide/patologia , Neutrófilos/efeitos dos fármacos , Antígenos CD18/metabolismo , Diferenciação Celular , Quimiotaxia , Dimetil Sulfóxido/farmacologia , Relação Dose-Resposta a Droga , Fator Estimulador de Colônias de Granulócitos/farmacologia , Células HL-60 , Humanos , Processamento de Imagem Assistida por Computador , Immunoblotting , Indóis/farmacologia , Interleucina-8/metabolismo , Interleucina-8/farmacologia , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Fosforilação , Receptores de Fator Estimulador de Colônias de Granulócitos/metabolismo , Receptores de Interleucina-8A/metabolismo , Proteína do Retinoblastoma/metabolismo , Estimulação Química , Superóxidos/metabolismoRESUMO
Approximately half of all human genes have CpG islands (CGIs)around their promoter regions. Although CGIs usually escape methylation, those on Chromosome X in females and those in the vicinity of imprinted genes are exceptions: They have both methylated and unmethylated alleles to display a "composite" pattern in methylation analysis. In addition, aberrant methylation of CGIs is known to often occur in cancer cells. Here we developed a simple HpaII-McrBC PCR method for discrimination of full, null, incomplete, and composite methylation patterns, and applied it to all computationally identified CGIs on human Chromosome 21q. This comprehensive analysis revealed that, although most CGIs (103 out of 149)escape methylation, a sizable fraction (31 out of 149)are fully methylated even in normal peripheral blood cells. Furthermore, we identified seven CGIs showing the composite methylation, and demonstrated that three of them are indeed methylated monoallelically. Further analyses using informative pedigrees revealed that two of the three are subject to maternal allele-specific methylation. Intriguingly, the other CGI is methylated in an allele-specific but parental-origin-independent manner. Thus, the cell seems to have a broader repertoire of methylating CGIs than previously thought, and our approach may contribute to uncover novel modes of allelic methylation.
Assuntos
Alelos , Mapeamento Cromossômico/métodos , Cromossomos Humanos Par 21/genética , Ilhas de CpG/genética , Metilação de DNA , Reação em Cadeia da Polimerase/métodos , Biologia Computacional/métodos , DNA/sangue , DNA/metabolismo , Feminino , Humanos , Leucócitos/química , Masculino , Mosaicismo/genética , Placenta/química , Polimorfismo de Nucleotídeo Único/genética , Projetos de Pesquisa , Análise de Sequência de DNA/métodosRESUMO
In order to identify single nucleotide polymorphisms (SNPs) and haplotype frequencies of CYP3A4 in a Japanese population, the distal enhancer and proximal promoter regions, all exons, and the surrounding introns were sequenced from genomic DNA of 416 Japanese subjects. We found 24 SNPs, including 17 novel ones: two in the distal enhancer, four in the proximal promoter, one in the 5'-untranslated region (UTR), seven in the introns, and three in the 3'-UTR. The most common SNP was c.1026+12G>A (IVS10+12G>A), with a 0.249 frequency. Four non-synonymous SNPs, c.554C>G (p.T185S, CYP3A4(*)16), c.830_831insA (p.E277fsX8, (*)6), c.878T>C (p.L293P, (*)18), and c.1088 C>T (p.T363M, (*)11) were found with frequencies of 0.014, 0.001, 0.028, and 0.002, respectively. No SNP was found in the known nuclear transcriptional factor-binding sites in the enhancer and promoter regions. Using these 24 SNPs, 16 haplotypes were unambiguously identified, and nine haplotypes were inferred by aid of an expectation-maximization-based program. In addition, using data from 186 subjects enabled a close linkage to be found between CYP3A4 and CYP3A5 SNPs, especially among the SNPs at c.1026+12 in CYP3A4 and c.219-237 (IVS3-237, a key SNP site for CYP3A5(*)3), c.865+77 (IVS9+77) and c.1523 in CYP3A5. This result suggested that CYP3A4 and CYP3A5 are within the same gene block. Haplotype analysis between CYP3A4 and CYP3A5 revealed several major haplotype combinations in the CYP3A4-CYP3A5 block. Our findings provide fundamental and useful information for genotyping CYP3A4 (and CYP3A5) in the Japanese, and probably Asian populations.