Displaying publications 421 - 440 of 951 in total

Abstract:
Sort:
  1. Kumar N, Mariappan V, Baddam R, Lankapalli AK, Shaik S, Goh KL, et al.
    Nucleic Acids Res, 2015 Jan;43(1):324-35.
    PMID: 25452339 DOI: 10.1093/nar/gku1271
    The discordant prevalence of Helicobacter pylori and its related diseases, for a long time, fostered certain enigmatic situations observed in the countries of the southern world. Variation in H. pylori infection rates and disease outcomes among different populations in multi-ethnic Malaysia provides a unique opportunity to understand dynamics of host-pathogen interaction and genome evolution. In this study, we extensively analyzed and compared genomes of 27 Malaysian H. pylori isolates and identified three major phylogeographic lineages: hspEastAsia, hpEurope and hpSouthIndia. The analysis of the virulence genes within the core genome, however, revealed a comparable pathogenic potential of the strains. In addition, we identified four genes limited to strains of East-Asian lineage. Our analyses identified a few strain-specific genes encoding restriction modification systems and outlined 311 core genes possibly under differential evolutionary constraints, among the strains representing different ethnic groups. The cagA and vacA genes also showed variations in accordance with the host genetic background of the strains. Moreover, restriction modification genes were found to be significantly enriched in East-Asian strains. An understanding of these variations in the genome content would provide significant insights into various adaptive and host modulation strategies harnessed by H. pylori to effectively persist in a host-specific manner.
    Matched MeSH terms: Genome, Bacterial*
  2. Panagiotou OA, Travis RC, Campa D, Berndt SI, Lindstrom S, Kraft P, et al.
    Eur Urol, 2015 Apr;67(4):649-57.
    PMID: 25277271 DOI: 10.1016/j.eururo.2014.09.020
    BACKGROUND: No single-nucleotide polymorphisms (SNPs) specific for aggressive prostate cancer have been identified in genome-wide association studies (GWAS).

    OBJECTIVE: To test if SNPs associated with other traits may also affect the risk of aggressive prostate cancer.

    DESIGN, SETTING, AND PARTICIPANTS: SNPs implicated in any phenotype other than prostate cancer (p≤10(-7)) were identified through the catalog of published GWAS and tested in 2891 aggressive prostate cancer cases and 4592 controls from the Breast and Prostate Cancer Cohort Consortium (BPC3). The 40 most significant SNPs were followed up in 4872 aggressive prostate cancer cases and 24,534 controls from the Prostate Cancer Association Group to Investigate Cancer Associated Alterations in the Genome (PRACTICAL) consortium.

    OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Odds ratios (ORs) and 95% confidence intervals (CIs) for aggressive prostate cancer were estimated.

    RESULTS AND LIMITATIONS: A total of 4666 SNPs were evaluated by the BPC3. Two signals were seen in regions already reported for prostate cancer risk. rs7014346 at 8q24.21 was marginally associated with aggressive prostate cancer in the BPC3 trial (p=1.6×10(-6)), whereas after meta-analysis by PRACTICAL the summary OR was 1.21 (95% CI 1.16-1.27; p=3.22×10(-18)). rs9900242 at 17q24.3 was also marginally associated with aggressive disease in the meta-analysis (OR 0.90, 95% CI 0.86-0.94; p=2.5×10(-6)). Neither of these SNPs remained statistically significant when conditioning on correlated known prostate cancer SNPs. The meta-analysis by BPC3 and PRACTICAL identified a third promising signal, marked by rs16844874 at 2q34, independent of known prostate cancer loci (OR 1.12, 95% CI 1.06-1.19; p=4.67×10(-5)); it has been shown that SNPs correlated with this signal affect glycine concentrations. The main limitation is the heterogeneity in the definition of aggressive prostate cancer between BPC3 and PRACTICAL.

    CONCLUSIONS: We did not identify new SNPs for aggressive prostate cancer. However, rs16844874 may provide preliminary genetic evidence on the role of the glycine pathway in prostate cancer etiology.

    PATIENT SUMMARY: We evaluated whether genetic variants associated with several traits are linked to the risk of aggressive prostate cancer. No new such variants were identified.

    Matched MeSH terms: Genome-Wide Association Study/methods*
  3. Tan JL, Ngeow YF, Wee WY, Wong GJ, Ng HF, Choo SW
    Sci Rep, 2014;4:7169.
    PMID: 25417557 DOI: 10.1038/srep07169
    Mycobacterium iranicum is a newly reported mycobacterial species. We present the first comparative study of M. iranicum UM_TJL and other mycobacteria. We found M. iranicum to have a close genetic association with environmental mycobacteria infrequently associated with human infections. Nonetheless, UM_TJL is also equipped with many virulence genes (some of which appear to be the consequence of transduction-related gene transfer) that have been identified in established human pathogens. Taken all together, our data suggest that M. iranicum is an environmental bacterium adapted for pathogenicity in the human host. This comparative study provides important clues and forms the basis for future functional studies on this mycobacterium.
    Matched MeSH terms: Genome, Bacterial*
  4. Hu T, Qiu W, He B, Zhang Y, Yu J, Liang X, et al.
    BMC Microbiol, 2014;14:293.
    PMID: 25433675 DOI: 10.1186/s12866-014-0293-4
    In recent years novel human respiratory disease agents have been described for Southeast Asia and Australia. The causative pathogens were classified as pteropine orthoreoviruses with a strong phylogenetic relationship to orthoreoviruses of bat origin.
    Matched MeSH terms: Genome, Viral/genetics
  5. Chan XY, Chua KO, How KY, Yin WF, Chan KG
    ScientificWorldJournal, 2014;2014:930727.
    PMID: 25436236 DOI: 10.1155/2014/930727
    Most Pseudomonas putida strains are environmental microorganisms exhibiting a wide range of metabolic capability but certain strains have been reported as rare opportunistic pathogens and some emerged as multidrug resistant P. putida. This study aimed to assess the drug resistance profile of, via whole genome analysis, P. putida strain T2-2 isolated from oral cavity. At the same time, we also compared the nonenvironmental strain with environmentally isolated P. putida. In silico comparative genome analysis with available reference strains of P. putida shows that T2-2 has lesser gene counts on carbohydrate and aromatic compounds metabolisms, which suggested its little versatility. The detection of its edd gene also suggested T2-2's catabolism of glucose via ED pathway instead of EMP pathway. On the other hand, its drug resistance profile was observed via in silico gene prediction and most of the genes found were in agreement with drug-susceptibility testing in laboratory by automated VITEK 2. In addition, the finding of putative genes of multidrug resistance efflux pump and ATP-binding cassette transporters in this strain suggests a multidrug resistant phenotype. In summary, it is believed that multiple metabolic characteristics and drug resistance in P. putida strain T2-2 helped in its survival in human oral cavity.
    Matched MeSH terms: Genome, Bacterial/genetics*
  6. Loh KH, Shao KT, Chen HM, Chen CH, Chong VC, Loo PL, et al.
    Mitochondrial DNA A DNA Mapp Seq Anal, 2016 11;27(6):4230-4231.
    PMID: 26000942
    In this study, the complete mitogenome sequence of the Zebra moray, Gymnomuraena zebra (Anguilliformes: Muraenidae) has been sequenced by the next-generation sequencing method. The assembled mitogenome consisting of 16,576 bp includes 13 protein coding genes, 22 transfer RNAs, and two ribosomal RNAs genes. The overall base composition of Zebra moray is 30.2% for A, 26.8% for C, 17.2% for G, and 25.8% for T and show 80% identities to Kidako moray, Gymnothorax kidako. The complete mitogenome of the Zebra moray provides an essential and important DNA molecular data for further phylogeography and evolutionary analysis for moray eel phylogeny.
    Matched MeSH terms: Genome, Mitochondrial/genetics*
  7. Krzeminska U, Wilson R, Rahman S, Song BK, Seneviratne S, Gan HM, et al.
    Mitochondrial DNA A DNA Mapp Seq Anal, 2016 Jul;27(4):2668-70.
    PMID: 26075478 DOI: 10.3109/19401736.2015.1043540
    The complete mitochondrial genomes of two jungle crows (Corvus macrorhynchos) were sequenced. DNA was extracted from tissue samples obtained from shed feathers collected in the field in Sri Lanka and sequenced using the Illumina MiSeq Personal Sequencer. Jungle crow mitogenomes have a structural organization typical of the genus Corvus and are 16,927 bp and 17,066 bp in length, both comprising 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal subunit genes, and a non-coding control region. In addition, we complement already available house crow (Corvus spelendens) mitogenome resources by sequencing an individual from Singapore. A phylogenetic tree constructed from Corvidae family mitogenome sequences available on GenBank is presented. We confirm the monophyly of the genus Corvus and propose to use complete mitogenome resources for further intra- and interspecies genetic studies.
    Matched MeSH terms: Genome, Mitochondrial/genetics*
  8. Lim YL, Yong D, Ee R, Tee KK, Yin WF, Chan KG
    J Biotechnol, 2015 Aug 10;207:32-3.
    PMID: 25975625 DOI: 10.1016/j.jbiotec.2015.04.027
    Serratia multitudinisentens RB-25(T) (=DSM 28811(T) =LMG 28304(T)) is a newly proposed type strain in the genus of Serratia isolated from a municipal landfill site. Here, we present the complete genome of S. multitudinisentens RB-25(T) which contains a complete chitinase operon and other chitin and N-acetylglucosamine utilisation enzymes. To our knowledge, this is the first report of the complete genome sequence of this novel isolate and its chitinase gene discovery.
    Matched MeSH terms: Genome, Bacterial*
  9. Thevarajoo S, Selvaratnam C, Chan KG, Goh KM, Chong CS
    Mar Genomics, 2015 Oct;23:49-50.
    PMID: 25957696 DOI: 10.1016/j.margen.2015.04.009
    Type strain Vitellibacter vladivostokensis KMM 3516(T) (=NBRC 16718(T)) belongs to the phylum Cytophaga-Flavobacterium-Bacteroides. To date, no genomes of the Vitellibacter spp. have been reported, and their metabolic pathways are unknown. This study reports the draft genome sequence of V. vladivostokensis. Moreover, mining of genes associated with proteolytic enzymes was performed to provide insights for further enzyme characterization.
    Matched MeSH terms: Genome, Bacterial/genetics*
  10. Lee WC, Anton BP, Wang S, Baybayan P, Singh S, Ashby M, et al.
    BMC Genomics, 2015;16:424.
    PMID: 26031894 DOI: 10.1186/s12864-015-1585-2
    The genome of the human gastric pathogen Helicobacter pylori encodes a large number of DNA methyltransferases (MTases), some of which are shared among many strains, and others of which are unique to a given strain. The MTases have potential roles in the survival of the bacterium. In this study, we sequenced a Malaysian H. pylori clinical strain, designated UM032, by using a combination of PacBio Single Molecule, Real-Time (SMRT) and Illumina MiSeq next generation sequencing platforms, and used the SMRT data to characterize the set of methylated bases (the methylome).
    Matched MeSH terms: Genome, Bacterial*
  11. Loh KH, Shao KT, Chen CH, Chen HM, Then AY, Loo PL, et al.
    PMID: 26029876 DOI: 10.3109/19401736.2015.1043530
    In this study, the complete mitogenome sequence of two moray eels of Gymnothorax formosus and Scuticaria tigrina (Anguilliformes: Muraenidae) has been sequenced by the next-generation sequencing method. The assembled mitogenome, with the length of 16,558 bp for G. formosus and 16,521 bp for S. tigrina, shows 78% identity to each other. Both mitogenomes follow the typical vertebrate arrangement, including 13 protein coding genes, 22 transfer RNAs, two ribosomal RNAs genes, and a non-coding control region of D-loop. The length of D-loop is 927 bp (G. formosus) and 850 bp (S. tigrina), which is located between tRNA-Pro and tRNA-Phe. The overall GC content is 45.5% for G. formosus and 47.9% for S. tigrina. Complete mitogenomes of G. formosus and S. tigrina provide essential and important DNA molecular data for further phylogenetic and evolutionary analysis for moray eel.
    Matched MeSH terms: Genome, Mitochondrial/genetics*
  12. Tan KK, Tan YC, Chang LY, Lee KW, Nore SS, Yee WY, et al.
    BMC Genomics, 2015;16:93.
    PMID: 25888205 DOI: 10.1186/s12864-015-1294-x
    Brucellosis is an important zoonotic disease that affects both humans and animals. We sequenced the full genome and characterised the genetic diversity of two Brucella melitensis isolates from Malaysia and the Philippines. In addition, we performed a comparative whole-genome single nucleotide polymorphism (SNP) analysis of B. melitensis strains collected from around the world, to investigate the potential origin and the history of the global spread of B. melitensis.
    Matched MeSH terms: Genome, Bacterial*
  13. Yu D, Zhang J, Li P, Zheng R, Shao C
    PLoS One, 2015;10(4):e0124825.
    PMID: 25875761 DOI: 10.1371/journal.pone.0124825
    he Chinese tiger frog Hoplobatrachus rugulosus is widely distributed in southern China, Malaysia, Myanmar, Thailand, and Vietnam. It is listed in Appendix II of CITES as the only Class II nationally-protected frog in China. The bred tiger frog known as the Thailand tiger frog, is also identified as H. rugulosus. Our analysis of the Cyt b gene showed high genetic divergence (13.8%) between wild and bred samples of tiger frog. Unexpected genetic divergence of the complete mt genome (14.0%) was also observed between wild and bred samples of tiger frog. Yet, the nuclear genes (NCX1, Rag1, Rhod, Tyr) showed little divergence between them. Despite this and their very similar morphology, the features of the mitochondrial genome including genetic divergence of other genes, different three-dimensional structures of ND5 proteins, and gene rearrangements indicate that H. rugulosus may be a cryptic species complex. Using Bayesian inference, maximum likelihood, and maximum parsimony analyses, Hoplobatrachus was resolved as a sister clade to Euphlyctis, and H. rugulosus (BT) as a sister clade to H. rugulosus (WT). We suggest that we should prevent Thailand tiger frogs (bred type) from escaping into wild environments lest they produce hybrids with Chinese tiger frogs (wild type).
    Matched MeSH terms: Genome, Mitochondrial/genetics*
  14. Tan SY, Dutta A, Jakubovics NS, Ang MY, Siow CC, Mutha NV, et al.
    BMC Bioinformatics, 2015;16:9.
    PMID: 25591325 DOI: 10.1186/s12859-014-0422-y
    Yersinia is a Gram-negative bacteria that includes serious pathogens such as the Yersinia pestis, which causes plague, Yersinia pseudotuberculosis, Yersinia enterocolitica. The remaining species are generally considered non-pathogenic to humans, although there is evidence that at least some of these species can cause occasional infections using distinct mechanisms from the more pathogenic species. With the advances in sequencing technologies, many genomes of Yersinia have been sequenced. However, there is currently no specialized platform to hold the rapidly-growing Yersinia genomic data and to provide analysis tools particularly for comparative analyses, which are required to provide improved insights into their biology, evolution and pathogenicity.
    Matched MeSH terms: Genome, Bacterial*
  15. Kwasiborski A, Mondy S, Chong TM, Barbey C, Chan KG, Beury-Cirou A, et al.
    Heredity (Edinb), 2015 May;114(5):476-84.
    PMID: 25585922 DOI: 10.1038/hdy.2014.121
    Social bacteria use chemical communication to coordinate and synchronize gene expression via the quorum-sensing (QS) regulatory pathway. In Pectobacterium, a causative agent of the blackleg and soft-rot diseases on potato plants and tubers, expression of the virulence factors is collectively controlled by the QS-signals N-acylhomoserine lactones (NAHLs). Several soil bacteria, such as the actinobacterium Rhodococcus erythropolis, are able to degrade NAHLs, hence quench the chemical communication and virulence of Pectobacterium. Here, next-generation sequencing was used to investigate structural and functional genomics of the NAHL-degrading R. erythropolis strain R138. The R. erythropolis R138 genome (6.7 Mbp) contained a single circular chromosome, one linear (250 kbp) and one circular (84 kbp) plasmid. Growth of R. erythropolis and P. atrosepticum was not altered in mixed-cultures as compared with monocultures on potato tuber slices. HiSeq-transcriptomics revealed that no R. erythropolis genes were differentially expressed when R. erythropolis was cultivated in the presence vs absence of the avirulent P. atrosepticum mutant expI, which is defective for QS-signal synthesis. By contrast 50 genes (<1% of the R. erythropolis genome) were differentially expressed when R. erythropolis was cultivated in the presence vs absence of the NAHL-producing virulent P. atrosepticum. Among them, quantitative real-time reverse-transcriptase-PCR confirmed that the expression of some alkyl-sulfatase genes decreased in the presence of a virulent P. atrosepticum, as well as deprivation of organic sulfur such as methionine, which is a key precursor in the synthesis of NAHL by P. atrosepticum.
    Matched MeSH terms: Genome, Bacterial*
  16. Gan HY, Gan HM, Tan MH, Lee YP, Austin CM
    Mitochondrial DNA A DNA Mapp Seq Anal, 2016 11;27(6):4099-4100.
    PMID: 25629489
    The complete mitochondrial genome of the hermit crab Clibanarius infraspinatus was recovered by genome skimming using Next-Gen sequencing. The Clibanarius infraspinatus mitogenome has 16,504 base pairs (67.94% A + T content) made up of 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs and a putative 1500 bp non-coding AT-rich region. The Clibanarius infraspinatus mitogenome sequence is the first for the family Diogenidae and the second for the superfamily Paguroidea and exhibits a translocation of the ND3 gene not previously reported for the Decapoda.
    Matched MeSH terms: Genome, Mitochondrial/genetics*
  17. Network and Pathway Analysis Subgroup of Psychiatric Genomics Consortium
    Nat Neurosci, 2015 Feb;18(2):199-209.
    PMID: 25599223 DOI: 10.1038/nn.3922
    Genome-wide association studies (GWAS) of psychiatric disorders have identified multiple genetic associations with such disorders, but better methods are needed to derive the underlying biological mechanisms that these signals indicate. We sought to identify biological pathways in GWAS data from over 60,000 participants from the Psychiatric Genomics Consortium. We developed an analysis framework to rank pathways that requires only summary statistics. We combined this score across disorders to find common pathways across three adult psychiatric disorders: schizophrenia, major depression and bipolar disorder. Histone methylation processes showed the strongest association, and we also found statistically significant evidence for associations with multiple immune and neuronal signaling pathways and with the postsynaptic density. Our study indicates that risk variants for psychiatric disorders aggregate in particular biological pathways and that these pathways are frequently shared between disorders. Our results confirm known mechanisms and suggest several novel insights into the etiology of psychiatric disorders.
    Matched MeSH terms: Genome-Wide Association Study/methods*
  18. Chook JB, Teo WL, Ngeow YF, Tee KK, Ng KP, Mohamed R
    J Clin Microbiol, 2015 Jun;53(6):1831-5.
    PMID: 25788548 DOI: 10.1128/JCM.03449-14
    Hepatitis B virus (HBV) has been divided into 10 genotypes, A to J, based on an 8% nucleotide sequence divergence between genotypes. The conventional practice of using a single set of primers to amplify a near-complete HBV genome is hampered by its low analytical sensitivity. The current practice of using overlapping conserved primer sets to amplify a complete HBV genome in a clinical sample is limited by the lack of pan-primers to detect all HBV genotypes. In this study, we designed six highly conserved, overlapping primer sets to cover the complete HBV genome. We based our design on the sequences of 5,154 HBV genomes of genotypes A to I downloaded from the GenBank nucleotide database. These primer sets were tested on 126 plasma samples from Malaysia, containing genotypes A to D and with viral loads ranging from 20 to >79,780,000 IU/ml. The overall success rates for PCR amplification and sequencing were >96% and >94%, respectively. Similarly, there was 100% amplification and sequencing success when the primer sets were tested on an HBV reference panel of genotypes A to G. Thus, we have established primer sets that gave a high analytical sensitivity for PCR-based detection of HBV and a high rate of sequencing success for HBV genomes in most of the viral genotypes, if not all, without prior known sequence data for the particular genotype/genome.
    Matched MeSH terms: Genome, Viral/genetics
  19. Gan HM, Gan HY, Lee YP, Grandjean F, Austin CM
    PMID: 25648916 DOI: 10.3109/19401736.2015.1007326
    The invasive freshwater crayfish Orconectes limosus mitogenome was recovered by genome skimming. The mitogenome is 16,223 base pairs in length consisting of 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs, and a non-coding AT-rich region. The O. limosus mitogenome has an AT bias of 71.37% and base composition of 39.8% for T, 10.3% for C, 31.5% for A, and 18.4% for G. The mitogene order is identical to two other genera of northern hemisphere crayfish that have been sequenced for this organelle.
    Matched MeSH terms: Genome, Mitochondrial*
  20. Mohd-Yusoff NF, Ruperao P, Tomoyoshi NE, Edwards D, Gresshoff PM, Biswas B, et al.
    G3 (Bethesda), 2015 Apr;5(4):559-67.
    PMID: 25660167 DOI: 10.1534/g3.114.014571
    Genetic structure can be altered by chemical mutagenesis, which is a common method applied in molecular biology and genetics. Second-generation sequencing provides a platform to reveal base alterations occurring in the whole genome due to mutagenesis. A model legume, Lotus japonicus ecotype Miyakojima, was chemically mutated with alkylating ethyl methanesulfonate (EMS) for the scanning of DNA lesions throughout the genome. Using second-generation sequencing, two individually mutated third-generation progeny (M3, named AM and AS) were sequenced and analyzed to identify single nucleotide polymorphisms and reveal the effects of EMS on nucleotide sequences in these mutant genomes. Single-nucleotide polymorphisms were found in every 208 kb (AS) and 202 kb (AM) with a bias mutation of G/C-to-A/T changes at low percentage. Most mutations were intergenic. The mutation spectrum of the genomes was comparable in their individual chromosomes; however, each mutated genome has unique alterations, which are useful to identify causal mutations for their phenotypic changes. The data obtained demonstrate that whole genomic sequencing is applicable as a high-throughput tool to investigate genomic changes due to mutagenesis. The identification of these single-point mutations will facilitate the identification of phenotypically causative mutations in EMS-mutated germplasm.
    Matched MeSH terms: Genome, Plant*
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links