Displaying publications 1401 - 1420 of 3507 in total

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  1. Pipatchartlearnwong K, Swatdipong A, Vuttipongchaikij S, Apisitwanich S
    BMC Genet, 2017 10 12;18(1):88.
    PMID: 29025415 DOI: 10.1186/s12863-017-0554-y
    BACKGROUND: Borassus flabellifer or Asian Palmyra palm is an important crop for local economies in the South and Southeast Asia for its fruit and palm sugar production. Archeological and historical evidence indicated the presence of this species in Southeast Asia dating back at least 1500 years. B. flabellifer is believed to be originated in Africa, spread to South Asia and introduced into Southeast Asia through commercial routes and dissemination of cultures, however, the nature of its invasion and settlement in Thailand is unclear.

    RESULTS: Here, we analyzed genetic data of 230 B. flabellifer accessions across Thailand using 17 EST-SSR and 12 gSSR polymorphic markers. Clustering analysis revealed that the population consisted of two genetic clusters (STRUCTURE K = 2). Cluster I is found mainly in southern Thailand, while Cluster II is found mainly in the northeastern. Those found in the central are of an extensive mix between the two. These two clusters are in moderate differentiation (F ST = 0.066 and N M = 3.532) and have low genetic diversity (HO = 0.371 and 0.416; AR = 2.99 and 3.19, for the cluster I and II respectively). The minimum numbers of founders for each genetic group varies from 3 to 4 individuals, based on simulation using different allele frequency assumptions. These numbers coincide with that B. flabellifer is dioecious, and a number of seeds had to be simultaneously introduced for obtaining both male and female founders.

    CONCLUSIONS: From these data and geographical and historical evidence, we hypothesize that there were at least two different invasive events of B. flabellifer in Thailand. B. flabellifer was likely brought through the Straits of Malacca to be propagated in the southern Thailand as one of the invasive events before spreading to the central Thailand. The second event likely occurred in Khmer Empire, currently Cambodia, before spreading to the northeastern Thailand.

    Matched MeSH terms: Sequence Analysis, DNA/methods*
  2. Parmin NA, Hashim U, Gopinath SCB
    Int J Biol Macromol, 2018 Feb;107(Pt B):1738-1746.
    PMID: 29030179 DOI: 10.1016/j.ijbiomac.2017.10.051
    Human Papillomavirus (HPV) is a standout amongst the most commonly reported over 100 types, among them genotypes 16, 18, 31 and 45 are the high-risk HPV. Herein, we designed the oligonucleotide probe for the detection of predominant HPV type 16 for the sensing applications. Conserved amino acid sequences within E6 region of the open reading frame in the HPV genome was used as the basis to design oligonucleotide probe to detect cervical cancer. Analyses of E6 amino acid sequences from the high-risk HPVs were done to check the percentage of similarity and consensus regions that cause different cancers, including cervical cancer. Basic local alignment search tools (BLAST) have given extra statistical parameters, for example, desire values (E-values) and score bits. The probe, 'GGG GTC GGT GGA CCG GTC GAT GTA' was designed with 66.7% GC content. This oligonucleotide probe is designed with the length of 24 mer, GC percent is between 40 and 70, and the melting point (Tm) is above 50°C. The probe needed an acceptable length between 22 and 31 mer. The choice of region is identified here can be used as a probe, has implications for HPV detection techniques in biosensor especially for clinical determination of cervical cancer.
    Matched MeSH terms: DNA Probes/metabolism*
  3. Thevarajoo S, Selvaratnam C, Chan KG, Goh KM, Chong CS
    Braz J Microbiol, 2017 07 19;49(1):10-12.
    PMID: 28778371 DOI: 10.1016/j.bjm.2017.03.013
    Vitellibacter aquimaris D-24T (=KCTC 42708T=DSM 101732T), a halophilic marine bacterium, was isolated from seawater collected from Desaru beach, Malaysia. Here, we present the draft genome sequence of D-24T with a genome size of approximately 3.1Mbp and G+C content of 39.93%. The genome of D-24T contains genes involved in reducing a potent greenhouse gas (N2O) in the environment and the degradation of proteinaceous compounds. Genome availability will provide insights into potential biotechnological and environmental applications of this bacterium.
    Matched MeSH terms: DNA, Bacterial/genetics
  4. Ali EZ, Yakob Y, Md Desa N, Ishak T, Zakaria Z, Ngu LK, et al.
    Malays J Pathol, 2017 08;39(2):99-106.
    PMID: 28866690 MyJurnal
    Fragile X syndrome (FXS) is a neurodevelopmental disorder commonly found worldwide, caused by the silencing of fragile X mental retardation 1 (FMR1) gene on the X-chromosome. Most of the patients lost FMR1 function due to an expansion of cytosine-guanine-guanine (CGG) repeat at the 5' untranslated region (5'UTR) of the gene. The purpose of this study is to identify the prevalence of FXS and characterize the FMR1 gene CGG repeats distribution among children with developmental disability in Malaysia. Genomic DNA of 2201 samples from different ethnicities (Malays, Chinese, Indian and others) of both genders were PCR-amplified from peripheral blood leukocytes based on specific primers at 5'UTR of FMR1 gene. Full mutations and mosaics were successfully identified by triple methylation specific PCR (ms-PCR) and subsequently verified with FragilEase kit. The findings revealed for the first time the prevalence of FXS full mutation in children with developmental disability in Malaysia was 3.5%, a slightly higher figure as compared to other countries. Molecular investigation also identified 0.2% and 0.4% probands have permutation and intermediate alleles, respectively. The CGG repeats length observation showed 95% of patients had normal alleles within 11 to 44 CGG repeats; with 29 repeats found most common among Malays and Indians while 28 repeats were most common among Chinese. In conclusion, this is the first report of prevalence and characterisation of CGG repeats that reflects genetic variability among Malaysian ethnic grouping.
    Matched MeSH terms: DNA; DNA Primers
  5. Ser HL, Tan WS, Ab Mutalib NS, Yin WF, Chan KG, Goh BH, et al.
    Braz J Microbiol, 2017 09 06;49(1):13-15.
    PMID: 28927873 DOI: 10.1016/j.bjm.2017.01.013
    As the largest genus in Actinobacteria family, Streptomyces species have the ability to synthesize numerous compounds of diverse structures with bioactivities. Streptomyces mangrovisoli MUSC 149T was previously isolated as a novel streptomycete from mangrove forest in east coast of Peninsular Malaysia. The high quality draft genome of MUSC 149T comprises 9,165,825bp with G+C content of 72.5%. Through bioinformatics analysis, 21 gene clusters identified in the genome were associated with the production of bioactive secondary metabolites. The presence of these biosynthetic gene clusters in MUSC 149T suggests the potential exploitation of the strain for production of medically important compounds.
    Matched MeSH terms: DNA, Bacterial/genetics
  6. Loo SK, Ab Hamid SS, Musa M, Wong KK
    Pathol Res Pract, 2018 Jan;214(1):134-143.
    PMID: 29137822 DOI: 10.1016/j.prp.2017.10.005
    Dysregulation of DNA (cytosine-5)-methyltransferase 1 (DNMT1) is associated with the pathogenesis of various types of cancer. It has been previously shown that DNMT1 is frequently expressed in diffuse large B-cell lymphoma (DLBCL), however its functions remain to be elucidated in the disease. In this study, we gene expression profiled (GEP) shRNA targeting DNMT1(shDNMT1)-treated germinal center B-cell-like DLBCL (GCB-DLBCL)-derived cell line (i.e. HT) compared with non-silencing shRNA (control shRNA)-treated HT cells. Independent gene set enrichment analysis (GSEA) performed using GEPs of shRNA-treated HT cells and primary GCB-DLBCL cases derived from two publicly-available datasets (i.e. GSE10846 and GSE31312) produced three separate lists of enriched gene sets for each gene sets collection from Molecular Signatures Database (MSigDB). Subsequent Venn analysis identified 268, 145 and six consensus gene sets from analyzing gene sets in C2 collection (curated gene sets), C5 sub-collection [gene sets from gene ontology (GO) biological process ontology] and Hallmark collection, respectively to be enriched in positive correlation with DNMT1 expression profiles in shRNA-treated HT cells, GSE10846 and GSE31312 datasets [false discovery rate (FDR) <0.05]. Cell cycle progression and DNA replication were among the significantly enriched biological processes (FDR <0.05). Expression of genes involved in the activation of cell cycle and DNA replication (e.g. CDK1, CCNA2, E2F2, PCNA, RFC5 and POLD3) were highly correlated (r>0.8) with DNMT1 expression and significantly downregulated (log fold-change DNA replication in DLBCL cells.
    Matched MeSH terms: DNA; DNA Replication
  7. Trottet A, Wilson B, Sew Wei Xin G, George C, Casten L, Schmoker C, et al.
    Environ Manage, 2018 02;61(2):275-290.
    PMID: 29204675 DOI: 10.1007/s00267-017-0966-5
    Resting strategies of planktonic organisms are important for the ecological processes of coastal waters and their impacts should be taken into consideration in management of water bodies used by multiple industries. We combined different approaches to evaluate the importance of resting stages in Singapore coastal waters. We used molecular approaches to improve the knowledge on Singapore biodiversity, we sampled and extracted cysts from sediments to evaluate the density of resting stages in Johor Strait, and we compared systematically information on Singapore planktonic biodiversity to existing published information on resting stages from these reported organisms. This is the first study evaluating the importance of resting stages in Singapore waters. Above 120 species reported in Singapore are known to produce resting stages though no previous work has ever been done to evaluate the importance of these strategies in these waters. The results from the resting stage survey confirmed 0.66 to 5.34 cyst g-1 dry weight sediment were present in the Johor Strait suggesting that cysts may be flushed by tidal currents into and out of the strait regularly. This also suggest that the blooms occurring in Singapore are likely due to secondary growth of Harmful Algae Bloom species in the water rather than from direct germination of cysts from sediment. Finally, we discuss the importance of these resting eggs for three main national industries in Singapore (shipping, marine aquaculture and provision of drinking water through seawater desalination). We argue that this study will serve as a baseline for some of the future management of Singapore waters.
    Matched MeSH terms: DNA, Bacterial/analysis
  8. Lim VC, Ramli R, Bhassu S, Wilson JJ
    PeerJ, 2018;6:e4572.
    PMID: 29607265 DOI: 10.7717/peerj.4572
    Background: Intense landscaping often alters the plant composition in urban areas. Knowing which plant species that pollinators are visiting in urban areas is necessary for understanding how landscaping impacts biodiversity and associated ecosystem services. The cave nectar bat,Eonycteris spelaea, is an important pollinator for many plants and is often recorded in human-dominated habitats. Previous studies of the diet ofE. spelaearelied on morphological identification of pollen grains found in faeces and on the body of bats and by necessity disregarded other forms of digested plant material present in the faeces (i.e., plant juice and remnants). The main objective of this study was to examine the diet of the nectarivorous bat,E. spelaea,roosting in an urban cave at Batu Caves, Peninsular Malaysia by identifying the plant material present in the faeces of bats using DNA metabarcoding.

    Methods: Faeces were collected under the roost ofE. spelaeaonce a week from December 2015 to March 2016. Plant DNA was extracted from the faeces, Polymerase chain reaction (PCR) amplified atITS2andrbcLregions and mass sequenced. The resultant plant operational taxonomic units were searched against NCBI GenBank for identification.

    Results: A total of 55 species of plants were detected from faeces ofE. spelaeaincludingArtocarpus heterophyllus, Duabanga grandifloraandMusaspp. which are likely to be important food resources for the cave nectar bat.

    Discussion: Many native plant species that had not been reported in previous dietary studies ofE. spelaeawere detected in this study includingBauhinia strychnoideaandUrophyllum leucophlaeum, suggesting thatE. spelaearemains a crucial pollinator for these plants even in highly disturbed habitats. The detection of many introduced plant species in the bat faeces indicates thatE. spelaeaare exploiting them, particularlyXanthostemon chrysanthus,as food resources in urban area. Commercial food crops were detected from all of the faecal samples, suggesting thatE. spelaeafeed predominantly on the crops particularly jackfruit and banana and play a significant role in pollination of economically important plants. Ferns and figs were also detected in the faeces ofE. spelaeasuggesting future research avenues to determine whether the 'specialised nectarivorous'E. spelaeafeed opportunistically on other parts of plants.

    Matched MeSH terms: DNA, Plant; DNA Barcoding, Taxonomic
  9. Rayani M, Hatam G, Unyah NZ, Ashrafmansori A, Abdullah WO, Hamat RA
    Iran J Parasitol, 2017 Oct-Dec;12(4):522-533.
    PMID: 29317877
    Background: This study is the first phylogenetic genotype analysis of Giardia lamblia in Iran. The main objective was to determine genotyping and identify the sub-assemblages of Giardia lamblia isolates involved in the transmission of giardiasis in Fars Province, south of Iran, in 2012.

    Methods: Forty G. lamblia isolates were collected from the patient's fecal samples with gastrointestinal discomfort referred to the health centers and hospitals in Shiraz, Fars Province, south of Iran. Purification of G. lamblia cysts from fecal samples and DNA extraction were performed using monolayer of sucrose density gradient and Phenol-Chloroform-Isoamylalcohol (PCI) respectively. Semi-nested PCR and sequence analysis were then performed using the primers (GDHeF, GDHiF, and GDHiR) which amplified a 432-bp fragment of Giardia glutamate dehydrogenase (gdh) gene. Phylogenetic analysis was carried out using a neighbor-joining tree composed of the nucleotide sequences of G. lamblia isolates obtained in this study and the known sequences isolates published in GenBank.

    Results: G. lamblia sub-assemblage AII was the most prevalent genotype with 80% of the cases and 20% of the cases belong to sub-assemblage BIII and BIV based on the DNA sequence of the gdh. G. lamblia isolates at Fars Province were widely distributed within assemblage A cluster (sub-assemblage AII) and the remaining isolates were dispersed throughout the assemblage B cluster (sub-assemblage BIII and BIV).

    Conclusion: PCR Sequencing and phylogenetic analysis was a proper molecular method for genotyping and discriminating of the of G. lamblia sub-assemblages in fecal samples, using the glutamate dehydrogenase gene that suggests a human contamination origin of giardiasis.
    Matched MeSH terms: DNA; DNA Primers
  10. Rizan N, Yew CY, Niknam MR, Krishnasamy J, Bhassu S, Hong GZ, et al.
    Sci Rep, 2018 01 17;8(1):896.
    PMID: 29343758 DOI: 10.1038/s41598-017-18825-6
    The exciting discovery of the semiconducting-like properties of deoxyribonucleic acid (DNA) and its potential applications in molecular genetics and diagnostics in recent times has resulted in a paradigm shift in biophysics research. Recent studies in our laboratory provide a platform towards detecting charge transfer mechanism and understanding the electronic properties of DNA based on the sequence-specific electronic response, which can be applied as an alternative to identify or detect DNA. In this study, we demonstrate a novel method for identification of DNA from different shrimp viruses and bacteria using electronic properties of DNA obtained from both negative and positive bias regions in current-voltage (I-V) profiles. Characteristic electronic properties were calculated and used for quantification and further understanding in the identification process. Aquaculture in shrimp industry is a fast-growing food sector throughout the world. However, shrimp culture in many Asian countries faced a huge economic loss due to disease outbreaks. Scientists have been using specific established methods for detecting shrimp infection, but those methods do have their significant drawbacks due to many inherent factors. As such, we believe that this simple, rapid, sensitive and cost-effective tool can be used for detection and identification of DNA from different shrimp viruses and bacteria.
    Matched MeSH terms: DNA/genetics*
  11. Zainuddin NH, Chee HY, Ahmad MZ, Mahdi MA, Abu Bakar MH, Yaacob MH
    J Biophotonics, 2018 08;11(8):e201700363.
    PMID: 29570957 DOI: 10.1002/jbio.201700363
    This paper presents the development of tapered optical fiber sensor to detect a specific Leptospira bacteria DNA. The bacteria causes Leptospirosis, a deadly disease but with common early flu-like symptoms. Optical single mode fiber (SMF) of 125 μm diameter is tapered to produce 12 μm waist diameter and 15 cm length. The novel DNA-based optical fiber sensor is functionalized by incubating the tapered region with sodium hydroxide (NaOH), (3-Aminopropyl) triethoxysilane and glutaraldehyde. Probe DNA is immobilized onto the tapered region and subsequently hybridized by its complementary DNA (cDNA). The transmission spectra of the DNA-based optical fiber sensor are measured in the 1500 to 1600 nm wavelength range. It is discovered that the shift of the wavelength in the SMF sensor is linearly proportional with the increase in the cDNA concentrations from 0.1 to 1.0 nM. The sensitivity of the sensor toward DNA is measured to be 1.2862 nm/nM and able to detect as low as 0.1 fM. The sensor indicates high specificity when only minimal shift is detected for non-cDNA testing. The developed sensor is able to distinguish between actual DNA of Leptospira serovars (Canicola and Copenhageni) against Clostridium difficile (control sample) at very low (femtomolar) target concentrations.
    Matched MeSH terms: DNA, Bacterial/analysis*
  12. Mohamad NA, Mustafa S, Khairil Mokhtar NF, El Sheikha AF
    J Sci Food Agric, 2018 Sep;98(12):4570-4577.
    PMID: 29505123 DOI: 10.1002/jsfa.8985
    BACKGROUND: The pharmaceutical industry has boosted gelatin consumption worldwide. This is supported by the availability of cost-effective gelatin production from porcine by-products. However, cross-contamination of gelatin materials, where porcine gelatin was unintentionally included in the other animal sources of gelatin, has caused significant concerns about halal authenticity. The real-time polymerase chain reaction (PCR) has enabled a highly specific and sensitive animal species detection method in various food products. Hence, such a technique was employed in the present study to detect and quantify porcine DNA in gelatin using a molecular beacon probe, with differences in performance between mitochondrial (cytochrome b gene) and chromosomal DNA-(MPRE42 repetitive element) based porcine-specific PCR assays being compared.

    RESULTS: A higher sensitivity was observed in chromosomal DNA (MPRE-PCR assay), where this assay allows the detection of gelatin DNA at amounts as as low as 1 pg, whereas mitochondrial DNA (CBH-PCR assay) can only detect at levels down to 10 pg of gelatin DNA. When an analysis with commercial gelatin and gelatin capsule samples was conducted, the same result was observed, with a significantly more sensitive detection being provided by the repetitive element of chromosomal DNA.

    CONCLUSION: The present study has established highly sensitive DNA-based porcine detection systems derived from chromosomal DNA that are feasible for highly processed products such as gelatin and gelatin capsules containing a minute amount of DNA. This sensitive detection method can also be implemented to assist the halal authentication process of various food products available on the market. © 2018 Society of Chemical Industry.

    Matched MeSH terms: DNA Primers/genetics
  13. Zakaria NNA, Okello EJ, Howes MJ, Birch-Machin MA, Bowman A
    Phytother Res, 2018 Jun;32(6):1064-1072.
    PMID: 29464849 DOI: 10.1002/ptr.6045
    The traditional practice of eating the flowers of Clitoria ternatea L. or drinking their infusion as herbal tea in some of the Asian countries is believed to promote a younger skin complexion and defend against skin aging. This study was conducted to investigate the protective effect of C. ternatea flower water extract (CTW) against hydrogen peroxide-induced cytotoxicity and ultraviolet (UV)-induced mitochondrial DNA (mtDNA) damage in human keratinocytes. The protective effect against hydrogen peroxide-induced cytotoxicity was determined by 3-(4, 5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium assay, and mtDNA damage induced by UV was determined by polymerase chain reaction. Preincubation of HaCaT with 100, 250, and 500 μg/ml CTW reduced cytotoxicity effects of H2 O2 compared with control (H2 O2 alone). CTW also significantly reduced mtDNA damage in UV-exposed HaCaT (p 
    Matched MeSH terms: DNA, Mitochondrial/adverse effects*
  14. Bakri NM, Ramachandran V, Kee HF, Subrayan V, Isa H, Ngah NF, et al.
    Kaohsiung J. Med. Sci., 2017 Dec;33(12):602-608.
    PMID: 29132549 DOI: 10.1016/j.kjms.2017.08.003
    Age-related macular degeneration (AMD) is the most widely recognised cause of irreversible vision loss and previous studies have suggested that the advancement of wet AMD is influenced by both modifiable and non-modifiable elements. Single nucleotide polymorphism (SNPs) and copy number of variations (CNVs) have been associated with AMD in various populations, however the results are conflicting. Our aim is to determine the CNVs of Complement Factor H-Related genes among Malaysian subjects with wet AMD. 130 patients with wet AMD and 120 healthy controls were included in this research. DNA was extracted from all subjects and CNVs of CFH, CFHR1 and CFHR3 genes; determined using quantitative real-time PCR and were compared between the two groups. A consistent association was observed between CFH gene and wet AMD susceptibility (P 
    Matched MeSH terms: DNA Copy Number Variations/genetics*
  15. Abdullahi, U.F., Igwenagu, E., Aliyu, S., Mu’azu, A., Naim, R., Wan-Taib, W.R.
    MyJurnal
    This study describes the development of a rapid and sensitive Loop-mediated isothermal
    amplification assay for detection of swine DNA in adulterated meat and meat products. The
    need to protect consumer’s right to eat foods of their choices, has made it imperative for
    researchers to develop efficient means of screening and certification of food products. Six sets
    of LAMP primers designed based on porcine tRNA lysine gene and ATPase subunit 8 genes
    were used for the assay. Amplification was carried out under constant temperature (630C), using
    a simple laboratory water bath. Average time spent in amplification and detection of results was
    25 min. All results were visually detected and confirmed by electrophoresis. Detection limit of
    the assay was 0.03 femtogram (fg) much high than the PCR assay, and detection probability of
    the assay was 100%. Detection of 0.5% of pork spiked with 99.5% of cattle beef is indicative
    of the sensitivity and robustness of the assay. This could serve as a prototype for development
    of a sensitive and inexpensive Swine DNA LAMP detection kit.
    Matched MeSH terms: DNA; DNA Primers
  16. Krzemińska U, Morales HE, Greening C, Nyári ÁS, Wilson R, Song BK, et al.
    Heredity (Edinb), 2018 04;120(4):296-309.
    PMID: 29180719 DOI: 10.1038/s41437-017-0020-7
    The House Crow (Corvus splendens) is a useful study system for investigating the genetic basis of adaptations underpinning successful range expansion. The species originates from the Indian subcontinent, but has successfully spread through a variety of thermal environments across Asia, Africa and Europe. Here, population mitogenomics was used to investigate the colonisation history and to test for signals of molecular selection on the mitochondrial genome. We sequenced the mitogenomes of 89 House Crows spanning four native and five invasive populations. A Bayesian dated phylogeny, based on the 13 mitochondrial protein-coding genes, supports a mid-Pleistocene (~630,000 years ago) divergence between the most distant genetic lineages. Phylogeographic patterns suggest that northern South Asia is the likely centre of origin for the species. Codon-based analyses of selection and assessments of changes in amino acid properties provide evidence of positive selection on the ND2 and ND5 genes against a background of purifying selection across the mitogenome. Protein homology modelling suggests that four amino acid substitutions inferred to be under positive selection may modulate coupling efficiency and proton translocation mediated by OXPHOS complex I. The identified substitutions are found within native House Crow lineages and ecological niche modelling predicts suitable climatic areas for the establishment of crow populations within the invasive range. Mitogenomic patterns in the invasive range of the species are more strongly associated with introduction history than climate. We speculate that invasions of the House Crow have been facilitated by standing genetic variation that accumulated due to diversifying selection within the native range.
    Matched MeSH terms: DNA, Mitochondrial/genetics
  17. Wassermann M, Raisch L, Lyons JA, Natusch DJD, Richter S, Wirth M, et al.
    PLoS One, 2017;12(11):e0187984.
    PMID: 29131856 DOI: 10.1371/journal.pone.0187984
    We examined Sarcocystis spp. in giant snakes from the Indo-Australian Archipelago and Australia using a combination of morphological (size of sporocyst) and molecular analyses. We amplified by PCR nuclear 18S rDNA from single sporocysts in order to detect mixed infections and unequivocally assign the retrieved sequences to the corresponding parasite stage. Sarcocystis infection was generally high across the study area, with 78 (68%) of 115 examined pythons being infected by one or more Sarcocystis spp. Among 18 randomly chosen, sporocyst-positive samples (11 from Southeast Asia, 7 from Northern Australia) the only Sarcocystis species detected in Southeast Asian snakes was S. singaporensis (in reticulated pythons), which was absent from all Australian samples. We distinguished three different Sarcocystis spp. in the Australian sample set; two were excreted by scrub pythons and one by the spotted python. The sequence of the latter is an undescribed species phylogenetically related to S. lacertae. Of the two Sarcocystis species found in scrub pythons, one showed an 18S rRNA gene sequence similar to S. zamani, which is described from Australia for the first time. The second sequence was identical/similar to that of S. nesbitti, a known human pathogen that was held responsible for outbreaks of disease among tourists in Malaysia. The potential presence of S. nesbitti in Australia challenges the current hypothesis of a snake-primate life cycle, and would have implications for human health in the region. Further molecular and biological characterizations are required to confirm species identity and determine whether or not the Australian isolate has the same zoonotic potential as its Malaysian counterpart. Finally, the absence of S. nesbitti in samples from reticulated pythons (which were reported to be definitive hosts), coupled with our phylogenetic analyses, suggest that alternative snake hosts may be responsible for transmitting this parasite in Malaysia.
    Matched MeSH terms: DNA, Protozoan/genetics
  18. Ahmad MK, Tabana YM, Ahmed MA, Sandai DA, Mohamed R, Ismail IS, et al.
    Malays J Med Sci, 2017 Dec;24(6):29-38.
    PMID: 29379384 DOI: 10.21315/mjms2017.24.6.4
    Background: A norovirus maintains its viability, infectivity and virulence by its ability to replicate. However, the biological mechanisms of the process remain to be explored. In this work, the NanoLuc™ Luciferase gene was used to develop a reporter-tagged replicon system to study norovirus replication.

    Methods: The NanoLuc™ Luciferase reporter protein was engineered to be expressed as a fusion protein for MNV-1 minor capsid protein, VP2. The foot-and-mouth disease virus 2A (FMDV2A) sequence was inserted between the 3'end of the reporter gene and the VP2 start sequence to allow co-translational 'cleavage' of fusion proteins during intracellular transcript expression. Amplification of the fusion gene was performed using a series of standard and overlapping polymerase chain reactions. The resulting amplicon was then cloned into three readily available backbones of MNV-1 cDNA clones.

    Results: Restriction enzyme analysis indicated that the NanoLucTM Luciferase gene was successfully inserted into the parental MNV-1 cDNA clone. The insertion was further confirmed by using DNA sequencing.

    Conclusion: NanoLuc™ Luciferase-tagged MNV-1 cDNA clones were successfully engineered. Such clones can be exploited to develop robust experimental assays for in vitro assessments of viral RNA replication.

    Matched MeSH terms: Sequence Analysis, DNA; DNA, Complementary
  19. Yew CW, Lu D, Deng L, Wong LP, Ong RT, Lu Y, et al.
    Hum Genet, 2018 Feb;137(2):161-173.
    PMID: 29383489 DOI: 10.1007/s00439-018-1869-0
    Southeast Asia (SEA) is enriched with a complex history of peopling. Malaysia, which is located at the crossroads of SEA, has been recognized as one of the hubs for early human migration. To unravel the genomic complexity of the native inhabitants of Malaysia, we sequenced 12 samples from 3 indigenous populations from Peninsular Malaysia and 4 native populations from North Borneo to a high coverage of 28-37×. We showed that the Negritos from Peninsular Malaysia shared a common ancestor with the East Asians, but exhibited some level of gene flow from South Asia, while the North Borneo populations exhibited closer genetic affinity towards East Asians than the Malays. The analysis of time of divergence suggested that ancestors of Negrito were the earliest settlers in the Malay Peninsula, whom first separated from the Papuans ~ 50-33 thousand years ago (kya), followed by East Asian (~ 40-15 kya), while the divergence time frame between North Borneo and East Asia populations predates the Austronesian expansion period implies a possible pre-Neolithic colonization. Substantial Neanderthal ancestry was confirmed in our genomes, as was observed in other East Asians. However, no significant difference was observed, in terms of the proportion of Denisovan gene flow into these native inhabitants from Malaysia. Judging from the similar amount of introgression in the Southeast Asians and East Asians, our findings suggest that the Denisovan gene flow may have occurred before the divergence of these populations and that the shared similarities are likely an ancestral component.
    Matched MeSH terms: DNA, Mitochondrial/genetics*
  20. Nordin N, Yusof NA, Radu S, Hushiarian R
    J Vis Exp, 2018 06 03.
    PMID: 29912194 DOI: 10.3791/56585
    Vibrio parahaemolyticus (V. parahaemolyticus) is a common foodborne pathogen that contributes to a large proportion of public health problems globally, significantly affecting the rate of human mortality and morbidity. Conventional methods for the detection of V. parahaemolyticus such as culture-based methods, immunological assays, and molecular-based methods require complicated sample handling and are time-consuming, tedious, and costly. Recently, biosensors have proven to be a promising and comprehensive detection method with the advantages of fast detection, cost-effectiveness, and practicality. This research focuses on developing a rapid method of detecting V. parahaemolyticus with high selectivity and sensitivity using the principles of DNA hybridization. In the work, characterization of synthesized polylactic acid-stabilized gold nanoparticles (PLA-AuNPs) was achieved using X-ray Diffraction (XRD), Ultraviolet-visible Spectroscopy (UV-Vis), Transmission Electron Microscopy (TEM), Field-emission Scanning Electron Microscopy (FESEM), and Cyclic Voltammetry (CV). We also carried out further testing of stability, sensitivity, and reproducibility of the PLA-AuNPs. We found that the PLA-AuNPs formed a sound structure of stabilized nanoparticles in aqueous solution. We also observed that the sensitivity improved as a result of the smaller charge transfer resistance (Rct) value and an increase of active surface area (0.41 cm2). The development of our DNA biosensor was based on modification of a screen-printed carbon electrode (SPCE) with PLA-AuNPs and using methylene blue (MB) as the redox indicator. We assessed the immobilization and hybridization events by differential pulse voltammetry (DPV). We found that complementary, non-complementary, and mismatched oligonucleotides were specifically distinguished by the fabricated biosensor. It also showed reliably sensitive detection in cross-reactivity studies against various food-borne pathogens and in the identification of V. parahaemolyticus in fresh cockles.
    Matched MeSH terms: DNA/genetics*
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