Displaying publications 341 - 360 of 3479 in total

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  1. Fulltext Psychrobacter Phage Encoding an Antibiotics Resistance Gene Represents a Novel Caudoviral Family
    Wang H, Ren L, Liang Y, Zheng K, Guo R, Liu Y, et al.
    Microbiol Spectr, 2023 Aug 17;11(4):e0533522.
    PMID: 37272818 DOI: 10.1128/spectrum.05335-22
    Psychrobacter is an important bacterial genus that is widespread in Antarctic and marine environments. However, to date, only two complete Psychrobacter phage sequences have been deposited in the NCBI database. Here, the novel Psychrobacter phage vB_PmaS_Y8A, infecting Psychrobacter HM08A, was isolated from sewage in the Qingdao area, China. The morphology of vB_PmaS_Y8A was characterized by transmission electron microscopy, revealing an icosahedral head and long tail. The genomic sequence of vB_PmaS_Y8A is linear, double-stranded DNA with a length of 40,226 bp and 44.1% G+C content, and encodes 69 putative open reading frames. Two auxiliary metabolic genes (AMGs) were identified, encoding phosphoadenosine phosphosulfate reductase and MarR protein. The first AMG uses thioredoxin as an electron donor for the reduction of phosphoadenosine phosphosulfate to phosphoadenosine phosphate. MarR regulates multiple antibiotic resistance mechanisms in Escherichia coli and is rarely found in viruses. No tRNA genes were identified and no lysogeny-related feature genes were detected. However, many similar open reading frames (ORFs) were found in the host genome, which may indicate that Y8A also has a lysogenic stage. Phylogenetic analysis based on the amino acid sequences of whole genomes and comparative genomic analysis indicate that vB_PmaS_Y8A contains a novel genomic architecture similar only to that of Psychrobacter phage pOW20-A, although at a low similarity. vB_PmaS_Y8A represents a new family-level virus cluster with 22 metagenomic assembled viral genomes, here named Minviridae. IMPORTANCE Although Psychrobacter is a well-known and important bacterial genus that is widespread in Antarctic and marine environments, genetic characterization of its phages is still rare. This study describes a novel Psychrobacter phage containing an uncharacterized antibiotic resistance gene and representing a new virus family, Minviridae. The characterization provided here will bolster current understanding of genomes, diversity, evolution, and phage-host interactions in Psychrobacter populations.
    Matched MeSH terms: DNA, Viral/genetics
  2. Fulltext Prevalence and type distribution of human papillomavirus (HPV) in Malaysian women with and without cervical cancer: an updated estimate
    Tan SC, Ismail MP, Duski DR, Othman NH, Ankathil R
    Biosci Rep, 2018 Apr 27;38(2).
    PMID: 29487170 DOI: 10.1042/BSR20171268
    Information on the prevalence and type distribution of human papillomavirus (HPV) among Malaysian women is currently limited. The present study therefore aimed to provide an updated estimate on the prevalence and type distribution of HPV among Malaysian women with and without cervical cancer. Total DNA was isolated from the cervical cell specimens of 185 histopathologically confirmed cervical cancer patients and 209 cancer-free healthy females who were tested negative in a recent Pap test. Viral-specific DNA was subsequently amplified with biotinylated primers and hybridized to HPV type-specific probes via a proprietary "flow-through hybridization" process for determination of HPV genotype. It was demonstrated that 83.2% of the cervical cancer patients and none (0.0%) of the cancer-free females were positive for HPV infection. Among HPV-positive subjects, 14 different viral genotypes were observed, namely HPV16, 18, 31, 33, 35, 45, 52, 53, 58, 66/68, 73, 81, 82, and 84/26. A total of 91.6% of the HPV-positive subjects had single-type HPV infections and the remaining 8.4% were simultaneously infected by two HPV genotypes. The most common HPV infections found were HPV16 (35.7%), HPV18 (26.0%), HPV58 (9.1%), and HPV33 (7.1%) single-type infections, followed by HPV16 + HPV18 co-infections (5.2%). The study has successfully provided an updated estimate on the prevalence and type distribution of HPV among Malaysian women with and without cervical cancer. These findings could contribute valuable information for appraisal of the impact and cost-effectiveness of prophylactic HPV vaccines in the Malaysian population.
    Matched MeSH terms: DNA, Viral/genetics*
  3. Fulltext Deep-WET: a deep learning-based approach for predicting DNA-binding proteins using word embedding techniques with weighted features
    Mahmud SMH, Goh KOM, Hosen MF, Nandi D, Shoombuatong W
    Sci Rep, 2024 Feb 05;14(1):2961.
    PMID: 38316843 DOI: 10.1038/s41598-024-52653-9
    DNA-binding proteins (DBPs) play a significant role in all phases of genetic processes, including DNA recombination, repair, and modification. They are often utilized in drug discovery as fundamental elements of steroids, antibiotics, and anticancer drugs. Predicting them poses the most challenging task in proteomics research. Conventional experimental methods for DBP identification are costly and sometimes biased toward prediction. Therefore, developing powerful computational methods that can accurately and rapidly identify DBPs from sequence information is an urgent need. In this study, we propose a novel deep learning-based method called Deep-WET to accurately identify DBPs from primary sequence information. In Deep-WET, we employed three powerful feature encoding schemes containing Global Vectors, Word2Vec, and fastText to encode the protein sequence. Subsequently, these three features were sequentially combined and weighted using the weights obtained from the elements learned through the differential evolution (DE) algorithm. To enhance the predictive performance of Deep-WET, we applied the SHapley Additive exPlanations approach to remove irrelevant features. Finally, the optimal feature subset was input into convolutional neural networks to construct the Deep-WET predictor. Both cross-validation and independent tests indicated that Deep-WET achieved superior predictive performance compared to conventional machine learning classifiers. In addition, in extensive independent test, Deep-WET was effective and outperformed than several state-of-the-art methods for DBP prediction, with accuracy of 78.08%, MCC of 0.559, and AUC of 0.805. This superior performance shows that Deep-WET has a tremendous predictive capacity to predict DBPs. The web server of Deep-WET and curated datasets in this study are available at https://deepwet-dna.monarcatechnical.com/ . The proposed Deep-WET is anticipated to serve the community-wide effort for large-scale identification of potential DBPs.
    Matched MeSH terms: DNA-Binding Proteins*
  4. Contrasting genetic and morphological differentiation among geographical lineages of a stenotopic miniature rasborine, Boraras maculatus, in Peninsular Malaysia
    Fam YQ, Jamaluddin JAF, Muhammad-Rasul AH, Ilham-Norhakim ML, Rosely NFN, Lavoué S
    J Fish Biol, 2024 Jan;104(1):171-183.
    PMID: 37775959 DOI: 10.1111/jfb.15572
    The variability in the stenotopic miniature rasborine Boraras maculatus (Cypriniformes: Danionidae: Rasborinae) across acidic-water habitats of Peninsular Malaysia (PM) was investigated using two molecular markers (the mitochondrial cytochrome c oxidase subunit I [COI] gene and the nuclear rhodopsin gene), as well as morphological evidence. Molecular phylogenetic analyses revealed differentiation among populations of B. maculatus in PM with the distinction of four allopatric lineages. Each of them was recognized as a putative species by automatic species delimitation methods. These lineages diverged from each other between 7.4 and 1.9 million years ago. A principal component analysis (PCA) was conducted to examine the multivariate variation in 11 morphometric measurements among three of these lineages. PCA results showed a significant overlap in morphological characteristics among these lineages. Additionally, a photograph-based machine learning approach failed to fully differentiate these lineages, suggesting limited morphological differentiation. B. maculatus represents a case of morphological stasis in a stenotopic miniature species. Strong habitat preference, coupled with long-term habitat fragmentation, may explain why each lineage of B. maculatus has a restricted distribution and did not disperse to other regions within and outside of PM, despite ample possibilities when the Sunda shelf was emerged and drained by large paleodrainages for most of the past 7 million years. The conservation status of B. maculatus and its peat swamp habitats are discussed, and it is concluded that peat swamps comprise several evolutionary units. Each of these units is considered a conservation unit and deserves appropriate protection.
    Matched MeSH terms: DNA, Mitochondrial/genetics
  5. Intraspecific genetic diversity with unrestricted gene flow in the domoic acid-producing diatom Nitzschia navis-varingica (Bacillariophyceae) from the Western Pacific
    Tan SN, Kotaki Y, Teng ST, Lim HC, Gao C, Lundholm N, et al.
    Harmful Algae, 2025 Jan;141:102769.
    PMID: 39645396 DOI: 10.1016/j.hal.2024.102769
    The benthic pennate diatom Nitzschia navis-varingica, known for producing domoic acid (DA) and its isomers, is widely distributed in the Western Pacific (WP) region. To investigate the genetic differentiation and gene flow patterns among the populations in the WP, the genetic diversity of 354 strains of N. navis-varingica was analysed using two nuclear-encoded rDNA loci: the large subunit rDNA (LSU rDNA) and the internal transcribed spacer 2 (ITS2). Frustule morphology of each strain was examined by TEM. The LSU rDNA phylogeny revealed a monophyletic lineage encompassing all strains, with sequence divergences of <0.9 %. Phylogenetic and population genetic analyses of ITS2 identified eight distinct clades (designated as Groups A to H) with moderate to high genetic heterogeneity (0.5-19.7 %). The low genetic differentiations between the geographically separated populations (pairwise FST of <0.03) suggested high gene flow and lack of spatial genetic structuring. Molecular clock analysis of the ITS2 phylogeny traced the evolutionary history of N. navis-varingica to the Eocene Epoch, and the split between clades likely occurred from the mid-Miocene to Pleistocene Epochs (10.8-1.2 Ma). The population dispersal in the WP were likely influenced by historical events like the Quarternary glacial cycles during the period, contributing to its homogenous distributions in the region.
    Matched MeSH terms: DNA, Ribosomal/genetics
  6. Newly developed mRNA vaccines induce immune responses in Litopenaeus vannamei shrimps during primary vaccination
    See SA, Bhassu S, Tang SS, Yusoff K
    Dev Comp Immunol, 2025 Jan;162:105264.
    PMID: 39299363 DOI: 10.1016/j.dci.2024.105264
    White spot syndrome virus (WSSV) causes highly destructive infection in crustacean aquaculture, often resulting in 100% mortality within a week. However, there is lack of studies addressing the safety issues of WSSV vaccines in shrimps. In this study, WSSV VP28 mRNA vaccines were developed using codon deoptimization approach. These vaccines were administered to Litopenaeus vannamei shrimps at various dosages to access their safety and the shrimps' immune responses using quantification PCR (qPCR). The findings of this study indicate that the expression level of codon deoptimized VP28 mRNA vaccines are lower compared to the wild type VP28 vaccines, as observed through a comparison of bioinformatic predictions and experimental results. Additionally, the total haemocyte count (THC) in shrimps injected with codon deoptimized VP28 vaccine was higher than those injected with wild type VP28 vaccines. Furthermore, the expression of immune-related genes differed between codon deoptimized and wild type VP28 vaccines. In summary, the results suggest that 0.01 μg codon deoptimized VP28-D1 mRNA vaccine is the most promising WSSV mRNA vaccine, displaying low pathogenicity and expression in shrimps. To the best of our knowledge, this research represents the first attempt to attenuate WSSV using codon deoptimization method and development of a potential mRNA vaccine for shrimp purpose. The study addresses an important gap in shrimp vaccine research, offering potential solutions for WSSV control in shrimps.
    Matched MeSH terms: DNA Virus Infections/immunology
  7. Distribution of Xanthomonas oryzae pv. oryzae DNA modification systems in Asia
    Choi SH, Vera Cruz CM, Leach JE
    Appl Environ Microbiol, 1998 May;64(5):1663-8.
    PMID: 9572933
    The presence or absence of two DNA modification systems, XorI and XorII, in 195 strains of Xanthomonas oryzae pv. oryzae collected from different major rice-growing countries of Asia was assessed. All four possible phenotypes (XorI+ XorII+, XorI+ XorII-, XorI- XorII+ and XorI- XorII-) were detected in the population at a ratio of approximately 1:2:2:2. The XorI+ XorII+ and XorI- XorII+ phenotypes were observed predominantly in strains from southeast Asia (Philippines, Malaysia, and Indonesia), whereas strains with the phenotypes XorI- XorII- and XorI+ XorII- were distributed in south Asia (India and Nepal) and northeast Asia (China, Korea, and Japan), respectively. Based on the prevalence and geographic distribution of the XorI and XorII systems, we suggest that the XorI modification system originated in northeast Asia and was later introduced to southeast Asia, while the XorII system originated in southeast Asia and moved to northeast Asia and south Asia. Genomic DNA from all tested strains of X. oryzae pv. oryzae that were resistant to digestion by endonuclease XorII or its isoschizomer PvuI also hybridized with a 7.0-kb clone that contained the XorII modification system, whereas strains that were digested by XorII or PvuI lacked DNA that hybridized with the clone. Size polymorphisms were observed in fragments that hybridized with the 7.0-kb clone. However, a single hybridization pattern generally was found in XorII+ strains within a country, indicating clonal maintenance of the XorII methyl-transferase gene locus. The locus was monomorphic for X. oryzae pv. oryzae strains from the Philippines and all strains from Indonesia and Korea.
    Matched MeSH terms: DNA Restriction Enzymes/metabolism*
  8. Molecular diversity of benthic harmful dinoflagellates on a tropical reef: Comparing natural and artificial substrate sampling methods using DNA metabarcoding and morphological analysis
    Kassim NS, Lee LK, Hii KS, Mohd Azmi NF, Baharudin SN, Liu M, et al.
    Harmful Algae, 2025 Feb;142:102795.
    PMID: 39947852 DOI: 10.1016/j.hal.2024.102795
    Harmful algal blooms in the benthic system (BHAB) are a major environmental problem that has increased worldwide in the context of global climate change. While systematic cell-based BHAB monitoring for risk assessment and early warning systems have been recommended, implementation of a standardized sampling method is challenging owing to the benthic nature of these harmful microalgal taxa. This study investigated the molecular diversity of benthic harmful dinoflagellates in tropical reefs of Perhentian Islands, Malaysia, using artificial substrate (AS) and sampling natural substrates (NS), combined with environmental DNA (eDNA) analysis and high-throughput amplicon sequencing targeting the small subunit (SSU) and large subunit (LSU) rDNA markers. Our results revealed that the AS method effectively captured a representative subset of the benthic dinoflagellate community, with significant taxonomic overlap between AS and NS. Both markers enabled high-resolution detection of BHAB taxa, particularly of Gambierdiscus and Ostreopsis, which are challenging to identify by light microscopy. The LSU rDNA marker provided finer taxonomic resolution, capturing a broader range of dinoflagellate species. The molecular approach consistently aligned with cell quantification data, supporting AS and DNA metabarcoding as robust methods for BHAB monitoring. The findings highlight the potential of these methods for early detection, especially areas susceptible for ciguatera and BHAB-related poisoning, offering a systematic approach for routine cell-based monitoring.
    Matched MeSH terms: DNA, Ribosomal/genetics
  9. Mitochondrial genomics identifies major haplogroups in Aboriginal Australians
    van Holst Pellekaan SM, Ingman M, Roberts-Thomson J, Harding RM
    Am J Phys Anthropol, 2006 Oct;131(2):282-94.
    PMID: 16596590
    We classified diversity in eight new complete mitochondrial genome sequences and 41 partial sequences from living Aboriginal Australians into five haplogroups. Haplogroup AuB belongs to global lineage M, and AuA, AuC, AuD, and AuE to N. Within N, we recognize subdivisions, assigning AuA to haplogroup S, AuD to haplogroup O, AuC to P4, and AuE to P8. On available evidence, (S)AuA and (M)AuB are widespread in Australia. (P4)AuC is found in the Riverine region of western New South Wales, and was identified by others in northern Australia. (O)AuD and (P8)AuE were clearly identified only from central Australia. Our eight Australian full mt genome sequences, combined with 20 others (Ingman and Gyllensten 2003 Genome Res. 13:1600-1606) and compared with full mt genome sequences from regions to the north that include Papua New Guinea, Malaya, and Andaman and Nicobar Islands, show that ancestral connections between regions are deep and limited to clustering at the level of the N and M macrohaplogroups. The Australian-specific distribution of the five haplogroups identified indicates genetic isolation over a long period. Ancestral connections within Australia are deeper than those reflected by known linguistic or culturally based affinities. Applying a coalescence analysis to a gene tree for the coding regions of the eight genomic sequences, we made estimates of time depth that support a continuity of presence for the descendants of a founding population already established by 40,000 years ago.
    Matched MeSH terms: DNA, Mitochondrial/genetics*
  10. Fulltext Overlooked: Extrachromosomal DNA and Their Possible Impact on Whole Genome Sequencing
    Dennin RH
    Malays J Med Sci, 2018 Mar;25(2):20-26.
    PMID: 30918452 DOI: 10.21315/mjms2018.25.2.3
    Extrachromosomal (ec) DNA in eukaryotic cells has been known for decades. The structures described range from linear double stranded (ds) DNA to circular dsDNA, distinct from mitochondrial (mt) DNA. The sizes of circular forms are described from some hundred base pairs (bp) up to more than 150 kbp. The number of molecules per cell ranges from several hundred to a thousand. Semi-quantitative determinations of circular dsDNA show proportions as high as several percentages of the total DNA per cell. These ecDNA fractions harbor sequences that are known to be present in chromosomal DNA (chrDNA) too. Sequencing projects on, for example the human genome, have to take into account the ecDNA sequences which are simultaneously ascertained; corrections cannot be performed retrospectively. Concerning the results of sequencings derived from extracted whole DNA: if the ecDNA fractions contained therein are not taken into account, erroneous conclusions at the chromosomal level may result.
    Matched MeSH terms: DNA, Mitochondrial; DNA, B-Form
  11. Ancient DNA analysis of elite nomadic warrior from Chinge-Tey I funerary commemorative complex in the "Valley of the Kings", Tuva
    Nedoluzhko A, Vergasova E, Sharko F, Agapitova N, Kharitonov D, Sukhanova X, et al.
    BMC Genomics, 2025 Mar 05;26(1):220.
    PMID: 40045199 DOI: 10.1186/s12864-025-11361-y
    BACKGROUND: In the Ist millennium BC bearers of the Scythian-type nomadic cultures inhabited the steppes of Eurasia, from Northern China to the Carpathians. According to archaeological data, the origin of nomadic life style and economy can be traced to the eastern part of this steppe "corridor", primarily to the territory of the present-day Republic of Tuva in Russia. Here, in the Turan-Uyuk Basin, also known as the "Valley of the Kings", some of the earliest known Scythian-type archaeological sites called Arzhan-1, Arzhan-2, Chinge-Tey I, Tunnug 1 were studied. Each of them is a large-scale funerary commemorative complex with burials of tribal nomadic leaders, surrounded by graves of supposed members of their families or associates. All these people belonged to the societies which are associated with the earliest nomadic cultures in Asia. Representatives of similar cultures will later be known and described as the Scythians/the Saka in Assyrian, Achaemenid, and Greek sources. Arzhan 2 and Chinge-Tey I elite level sites as well as ordinary pastoralist burials of the early-Scythian period in Tuva are attributed to the Aldy-Bel archaeological culture of the Early Iron Age (8th- 6th century BC). Taking the first step to shed light on the genetic origin of Aldy-Bel elites, we carried out a comparative genome-wide analysis of an elite level person buried in grave 9 at Chinge-Tey I (7th- 6th centuries BC) and two published earlier genomes of individuals, whose burials (graves 14 and 22) accompanied the 'royal couple' (grave 5) at Arzhan-2. This study aims also at checking a hypothesis of genetic kinship between human individuals buried in the large-scale burial complexes of the "Valley of the Kings" and brings up the issue of possible dynastic connections of local elites, buried under different kurgans of the valley.

    RESULTS: First, ancient DNA analysis of an elite nomadic warrior from Chinge-Tey I has been carried out, thus a third wide-genome dataset for Aldy-Bel culture- one of the earliest nomadic cultures in Asia, is presented in this study. Second, we undertook a comparative analysis of genome-wide data of three mentioned Aldy-Bel culture representatives and individuals of the other Bronze and Early Iron Age population groups of Asia to estimate their possible genetic connections. Then, kinship analysis was undertaken for these three Aldy-Bel culture individuals. Finally, mitochondrial and Y-chromosome haplogroups of Chinge-Tey princely person were compared to those of other Aldy-Bel culture representatives and to individuals of subsequent Scythian-type Uyuk-Sagly culture in Tuva.

    CONCLUSION: (1) Generating the third wide-genome of the enabled us to undertake its comparison with two other genomes of Aldy-Bel culture representatives (Arzhan-2, graves 14 and 22) and with other Bronze and Early Iron Age population groups in Asia to trace the origin and genetic connection of Aldy-Bel population, representing one of the earliest Scythian-type nomadic group. (2) The results obtained show that the princely individual from Chinge-Tey I and two 'king's associates' from Arzhan-2 were genetically close to nomads of simultaneous Tasmola culture in Eastern and Central Kazakhstan and pastoralists buried in the Early Iron Age cemeteries of present-day Xinjiang (first of all, Abusanteer archaeological site). Aldy-Bel culture representatives appeared also close to individuals of the Middle Bronze Age Okunevo culture in the Minusinsk Basin. Besides, Aldy-Bel pastoralists turned out genetically close to nomads of the subsequent Uyuk-Sagly culture in Mongolia (5th - 3rd centuries BC). (3) Ancient DNA kinship analyses, undertaken for three Aldy-Bel culture individuals pointed out to the absence of their tribe kinship. (4) On the other hand, Chinge-Tey warrior's mitochondrial haplogroup G was previously described in two (graves 14 and 5) individuals from Arzhan-2, including a female individual from the "royal" tomb 5. This result provided a possibility of maternal kinship among this so called 'queen' from Arzhan-2 and the princely person from Chinge-Tey I. This possibility supported a hypothesis of their family ties suggested on archaeological materials. Y-chromosome haplogroup Q1b1, revealed for the princely person, was widely distributed among local people of Aldy-Bel and subsequent Uyuk-Sagly cultures.

    Matched MeSH terms: DNA, Mitochondrial/genetics
  12. Fulltext Nanoparticle-Encapsulated Camptothecin: Epigenetic Modulation in DNA Repair Mechanisms in Colon Cancer Cells
    Farhana A, Koh AE, Tong JB, Alsrhani A, Kumar Subbiah S, Mok PL
    Molecules, 2021 Sep 06;26(17).
    PMID: 34500845 DOI: 10.3390/molecules26175414
    Molecular crosstalk between the cellular epigenome and genome converge as a synergistic driver of oncogenic transformations. Besides other pathways, epigenetic regulatory circuits exert their effect towards cancer progression through the induction of DNA repair deficiencies. We explored this mechanism using a camptothecin encapsulated in β-cyclodextrin-EDTA-Fe3O4 nanoparticles (CPT-CEF)-treated HT29 cells model. We previously demonstrated that CPT-CEF treatment of HT29 cells effectively induces apoptosis and cell cycle arrest, stalling cancer progression. A comparative transcriptome analysis of CPT-CEF-treated versus untreated HT29 cells indicated that genes controlling mismatch repair, base excision repair, and homologues recombination were downregulated in these cancer cells. Our study demonstrated that treatment with CPT-CEF alleviated this repression. We observed that CPT-CEF exerts its effect by possibly affecting the DNA repair mechanism through epigenetic modulation involving genes of HMGB1, APEX1, and POLE3. Hence, we propose that CPT-CEF could be a DNA repair modulator that harnesses the cell's epigenomic plasticity to amend DNA repair deficiencies in cancer cells.
    Matched MeSH terms: DNA Polymerase III/genetics; DNA Polymerase III/metabolism; DNA Repair/drug effects*; DNA-Binding Proteins/genetics; DNA-Binding Proteins/metabolism
  13. Fulltext Scanning the effects of ethyl methanesulfonate on the whole genome of Lotus japonicus using second-generation sequencing analysis
    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: Sequence Analysis, DNA; DNA, Plant/analysis; DNA, Plant/chemistry
  14. Fulltext First case of a naturally acquired human infection with Plasmodium cynomolgi
    Ta TH, Hisam S, Lanza M, Jiram AI, Ismail N, Rubio JM
    Malar J, 2014;13:68.
    PMID: 24564912 DOI: 10.1186/1475-2875-13-68
    Since 1960, a total of seven species of monkey malaria have been reported as transmissible to man by mosquito bite: Plasmodium cynomolgi, Plasmodium brasilianum, Plasmodium eylesi, Plasmodium knowlesi, Plasmodium inui, Plasmodium schwetzi and Plasmodium simium. With the exception of P. knowlesi, none of the other species has been found to infect humans in nature. In this report, it is described the first known case of a naturally acquired P. cynomolgi malaria in humans.The patient was a 39-year-old woman from a malaria-free area with no previous history of malaria or travel to endemic areas. Initially, malaria was diagnosed and identified as Plasmodium malariae/P. knowlesi by microscopy in the Terengganu State Health Department. Thick and thin blood films stained with 10% Giemsa were performed for microscopy examination. Molecular species identification was performed at the Institute for Medical Research (IMR, Malaysia) and in the Malaria & Emerging Parasitic Diseases Laboratory (MAPELAB, Spain) using different nested PCR methods.Microscopic re-examination in the IMR showed characteristics of Plasmodium vivax and was confirmed by a nested PCR assay developed by Snounou et al. Instead, a different PCR assay plus sequencing performed at the MAPELAB confirmed that the patient was infected with P. cynomolgi and not with P. vivax.This is the first report of human P. cynomolgi infection acquired in a natural way, but there might be more undiagnosed or misdiagnosed cases, since P. cynomolgi is morphologically indistinguishable from P. vivax, and one of the most used PCR methods for malaria infection detection may identify a P. cynomolgi infection as P. vivax.Simian Plasmodium species may routinely infect humans in Southeast Asia. New diagnostic methods are necessary to distinguish between the human and monkey malaria species. Further epidemiological studies, incriminating also the mosquito vector(s), must be performed to know the relevance of cynomolgi malaria and its implication on human public health and in the control of human malaria.The zoonotic malaria cannot be ignored in view of increasing interactions between man and wild animals in the process of urbanization.
    Matched MeSH terms: DNA, Protozoan/genetics; DNA, Protozoan/chemistry; Sequence Analysis, DNA
  15. Fulltext DNA methylation and expression of the EgDEF1 gene and neighboring retrotransposons in mantled somaclonal variants of oil palm
    Jaligot E, Hooi WY, Debladis E, Richaud F, Beulé T, Collin M, et al.
    PLoS One, 2014;9(3):e91896.
    PMID: 24638102 DOI: 10.1371/journal.pone.0091896
    The mantled floral phenotype of oil palm (Elaeis guineensis) affects somatic embryogenesis-derived individuals and is morphologically similar to mutants defective in the B-class MADS-box genes. This somaclonal variation has been previously demonstrated to be associated to a significant deficit in genome-wide DNA methylation. In order to elucidate the possible role of DNA methylation in the transcriptional regulation of EgDEF1, the APETALA3 ortholog of oil palm, we studied this epigenetic mark within the gene in parallel with transcript accumulation in both normal and mantled developing inflorescences. We also examined the methylation and expression of two neighboring retrotransposons that might interfere with EgDEF1 regulation. We show that the EgDEF1 gene is essentially unmethylated and that its methylation pattern does not change with the floral phenotype whereas expression is dramatically different, ruling out a direct implication of DNA methylation in the regulation of this gene. Also, we find that both the gypsy element inserted within an intron of the EgDEF1 gene and the copia element located upstream from the promoter are heavily methylated and show little or no expression. Interestingly, we identify a shorter, alternative transcript produced by EgDEF1 and characterize its accumulation with respect to its full-length counterpart. We demonstrate that, depending on the floral phenotype, the respective proportions of these two transcripts change differently during inflorescence development. We discuss the possible phenotypical consequences of this alternative splicing and the new questions it raises in the search for the molecular mechanisms underlying the mantled phenotype in the oil palm.
    Matched MeSH terms: Sequence Analysis, DNA; DNA, Complementary; DNA Methylation*
  16. The complete mitogenome of the red claw crayfish Cherax quadricarinatus (Von Martens, 1868) (Crustacea: Decapoda: Parastacidae)
    Gan HM, Tan MH, Austin CM
    Mitochondrial DNA A DNA Mapp Seq Anal, 2016;27(1):385-6.
    PMID: 24617485 DOI: 10.3109/19401736.2014.895997
    The commercial freshwater crayfish Cherax quadricarinatus complete mitochondrial genome was recovered from partial genome sequencing using the MiSeq Personal Sequencer. The mitogenome has 15,869 base pairs consisting of 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs, and a non-coding AT-rich region. The base composition of C. quadricarinatus is 32.16% for T, 23.39% for C, 33.26% for A, and 11.19% for G, with an AT bias of 65.42%.
    Matched MeSH terms: DNA, Mitochondrial/genetics; Sequence Analysis, DNA/veterinary
  17. The complete mitogenome of the Australian crayfish Geocharax gracilis Clark 1936 (Crustacea: Decapoda: Parastacidae)
    Gan HM, Tan MH, Gan HY, Lee YP, Schultz MB, Austin CM
    Mitochondrial DNA A DNA Mapp Seq Anal, 2016;27(2):826-7.
    PMID: 24845437 DOI: 10.3109/19401736.2014.919460
    The mitogenome of the black yabby, Geocharax gracilis, was sequenced using the MiSeq Personal Sequencer. It has 15,924 base pairs consisting of 13 protein-coding genes, 2 ribosomal subunit genes, 23 transfer RNAs, and a non-coding AT-rich region. The base composition of G. gracilis mitogenome is 32.18% for T, 22.32% for C, 34.83% for A, and 10.68% for G, with an AT bias of 67.01%. The mitogenome gene order is typical for that of parastacid crayfish with the exception of some minor rearrangements involving tRNA genes.
    Matched MeSH terms: DNA, Mitochondrial/genetics*; Sequence Analysis, DNA/veterinary
  18. Phylogeography and demographic history of two widespread Indo-Pacific mudskippers (Gobiidae: Periophthalmus)
    Polgar G, Zane L, Babbucci M, Barbisan F, Patarnello T, Rüber L, et al.
    Mol Phylogenet Evol, 2014 Apr;73:161-76.
    PMID: 24486991 DOI: 10.1016/j.ympev.2014.01.014
    This study provides a first description of the phylogeographic patterns and evolutionary history of two species of the mudskipper genus Periophthalmus. These amphibious gobies are distributed throughout the whole Indo-Pacific region and Atlantic coast of Africa, in peritidal habitats of soft-bottom coastal ecosystems. Three sequence datasets of two widely distributed species, Periophthalmus argentilineatus and P. kalolo, were obtained by amplifying and sequencing two mtDNA markers (D-loop and 16S rDNA) and the nDNA rag1 region. The three datasets were then used to perform phylogeographic, demographic and population genetic analyses. Our results indicate that tectonic events and past climatic oscillations strongly contributed to shape present genetic differentiation, phylogeographic and demographic patterns. We found support for the monophyly of P. kalolo, and only shallow genetic differentiation between East-African and Indo-Malayan populations of this species. However, our collections of the morphospecies P. argentilineatus include three molecularly distinct lineages, one of them more closely related to P. kalolo. The presence of Miocenic timings for the most recent common ancestors of some of these morphologically similar clades, suggests the presence of strong stabilising selection in mudskippers' habitats. At population level, demographic analyses and palaeoecological records of mangrove ecosystems suggest that Pleistocene bottlenecks and expansion plus secondary contact events of the studied species were associated with recurrent sea transgressions during interglacials, and sea regressions or stable regimes during glacials, respectively.
    Matched MeSH terms: DNA, Mitochondrial/genetics; DNA, Ribosomal/genetics
  19. Detection and characterization of viruses of the genus Megalocytivirus in ornamental fish imported into an Australian border quarantine premises: an emerging risk to national biosecurity
    Nolan D, Stephens F, Crockford M, Jones JB, Snow M
    J Fish Dis, 2015 Feb;38(2):187-95.
    PMID: 24475941 DOI: 10.1111/jfd.12222
    This report documents an emerging trend of identification of Megalocytivirus-like inclusions in a range of ornamental fish species intercepted during quarantine detention at the Australian border. From September 2012 to February 2013, 5 species of fish that had suffered mortality levels in excess of 25% whilst in the post-entry quarantine and had Megalocytivirus-like inclusion bodies in histological sections were examined by PCR. The fish had been imported from Singapore, Malaysia and Sri Lanka. Ninety-seven of 111 individual fish from affected tanks of fish tested were positive for the presence of Megalocytivirus by PCR. Sequence analysis of representative PCR products revealed an identical sequence of 621 bp in all cases which was identical to a previously characterized Megalocytivirus (Sabah/RAA1/2012 strain BMGIV48). Phylogenetic analysis of available Megalocytivirus major capsid protein (MCP) sequences confirmed the existence of 3 major clades of Megalocytivirus. The virus detected in this study was identified as a member of Genotype II. The broad host range and pathogenicity of megalocytiviruses, coupled to the documented spread of ornamental fish into the environment, render this a significant and emerging biosecurity threat to Australia.
    Matched MeSH terms: DNA Virus Infections/transmission; DNA Virus Infections/veterinary*; DNA Virus Infections/virology
  20. Fulltext Development of chloroplast simple sequence repeats (cpSSRs) for the intraspecific study of Gracilaria tenuistipitata (Gracilariales, Rhodophyta) from different populations
    Song SL, Lim PE, Phang SM, Lee WW, Hong DD, Prathep A
    BMC Res Notes, 2014;7:77.
    PMID: 24490797 DOI: 10.1186/1756-0500-7-77
    Gracilaria tenuistipitata is an agarophyte with substantial economic potential because of its high growth rate and tolerance to a wide range of environment factors. This red seaweed is intensively cultured in China for the production of agar and fodder for abalone. Microsatellite markers were developed from the chloroplast genome of G. tenuistipitata var. liui to differentiate G. tenuistipitata obtained from six different localities: four from Peninsular Malaysia, one from Thailand and one from Vietnam. Eighty G. tenuistipitata specimens were analyzed using eight simple sequence repeat (SSR) primer-pairs that we developed for polymerase chain reaction (PCR) amplification.
    Matched MeSH terms: DNA Primers; DNA, Chloroplast/genetics*; Random Amplified Polymorphic DNA Technique
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