Displaying publications 41 - 60 of 862 in total

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  1. Three new species of Krogia (Ramalinaceae, lichenised Ascomycota) from the Paleotropics
    Kistenich S, Rikkinen JK, Thüs H, Vairappan CS, Wolseley PA, Timdal E
    MycoKeys, 2018.
    PMID: 30294209 DOI: 10.3897/mycokeys.40.26025
    Krogiaborneensis Kistenich & Timdal, K.isidiata Kistenich & Timdal and K.macrophylla Kistenich & Timdal are described as new species, the first from Borneo and the two latter from New Caledonia. The new species are supported by morphology, secondary chemistry and DNA sequence data. Krogiaborneensis and K.isidiata contain sekikaic and homosekikaic acid, both compounds reported here for the first time from the genus. Krogiamacrophylla contains an unknown compound apparently related to boninic acid as the major compound. DNA sequences (mtSSU and nrITS) are provided for the first time for Krogia and a phylogeny of the genus based on 15 accessions of five of the six accepted species is presented. Krogiaantillarum is reported as new to Brazil, Guatemala and Mexico.
    Matched MeSH terms: Sequence Analysis, DNA
  2. Three Taxa in One: Cryptic Diversity in the Black Fly Simulium nobile (Diptera: Simuliidae) in Southeast Asia
    Low VL, Takaoka H, Pramual P, Adler PH, Ya'cob Z, Chen CD, et al.
    J Med Entomol, 2016 07;53(4):972-976.
    PMID: 27208009
    We access the molecular diversity of the black fly Simulium nobile De Mejiere, using the universal cytochrome c oxidase subunit I (COI) barcoding gene, across its distributional range in Southeast Asia. Our phylogenetic analyses recovered three well-supported mitochondrial lineages of S. nobile, suggesting the presence of cryptic species. Lineage A is composed of a population from Sabah, East Malaysia (Borneo); lineage B represents the type population from Java, Indonesia; and lineage C includes populations from the mainland of Southeast Asia (Peninsular Malaysia and Thailand). The genetic variation of lineage C on the mainland is greater than that of lineages A and B on the islands of Borneo and Java. Our study highlights the value of a molecular approach in assessing species status of simuliids in geographically distinct regions.
    Matched MeSH terms: Sequence Analysis, DNA
  3. Fulltext The use of next generation sequencing for improving food safety: Translation into practice
    Jagadeesan B, Gerner-Smidt P, Allard MW, Leuillet S, Winkler A, Xiao Y, et al.
    Food Microbiol, 2019 Jun;79:96-115.
    PMID: 30621881 DOI: 10.1016/j.fm.2018.11.005
    Next Generation Sequencing (NGS) combined with powerful bioinformatic approaches are revolutionising food microbiology. Whole genome sequencing (WGS) of single isolates allows the most detailed comparison possible hitherto of individual strains. The two principle approaches for strain discrimination, single nucleotide polymorphism (SNP) analysis and genomic multi-locus sequence typing (MLST) are showing concordant results for phylogenetic clustering and are complementary to each other. Metabarcoding and metagenomics, applied to total DNA isolated from either food materials or the production environment, allows the identification of complete microbial populations. Metagenomics identifies the entire gene content and when coupled to transcriptomics or proteomics, allows the identification of functional capacity and biochemical activity of microbial populations. The focus of this review is on the recent use and future potential of NGS in food microbiology and on current challenges. Guidance is provided for new users, such as public health departments and the food industry, on the implementation of NGS and how to critically interpret results and place them in a broader context. The review aims to promote the broader application of NGS technologies within the food industry as well as highlight knowledge gaps and novel applications of NGS with the aim of driving future research and increasing food safety outputs from its wider use.
    Matched MeSH terms: Sequence Analysis, DNA
  4. The ribosomal protein L19 mRNA is induced by copper exposure in the swordtail fish, Xiphophorus helleri
    Aliza D, Tey CL, Ismail IS, Kuah MK, Shu-Chien AC, Muhammad TS
    Mol Biol Rep, 2012 Apr;39(4):4823-9.
    PMID: 21956757 DOI: 10.1007/s11033-011-1275-3
    Teleosts are useful vertebrate model species for understanding copper toxicity due to the dual entry route for copper intake via the gills and intestine. In this present study, we utilized the differential display reverse transcription-polymerase chain reaction to isolate potential novel hepatic genes induced by sublethal copper exposure in the freshwater swordtail fish, Xiphophorus helleri. Full length cloning of a cDNA fragment induced by copper exposure to 1 μg/ml during 24 h resulted in the positive identification of a hepatic ribosomal protein L19 (RPL19) gene. Further characterization of this gene revealed that its transcriptional expression was dependent on dosage and time of copper exposure. This study describes for the first time the involvement of RPL19 in copper toxicity, probably as a result of increase in ribosome synthesis rate to support activities such as cellular protein translation, transcriptional activation and mRNA stabilization during sublethal copper exposure.
    Matched MeSH terms: Sequence Analysis, DNA
  5. Fulltext The presence of single-nucleotide polymorphisms in Hps4 gene in a subset of schizophrenic patients in Pahang: a preliminary study
    Norafiza Zainuddin, Maizatul Akma Mamat, Norlelawati A. Talib
    International Journal of Allied Health Sciences, 2017;1(2):14-27.
    MyJurnal
    Schizophrenia is a devastating mental disorder that affects people’s normal life with heterogeneous features of its clinical presentation, as well as its molecular attribute. In order to identify the potential molecular aberration, particularly single nucleotide polymorphism (SNP) which could be important in the aetiology of schizophrenia, polymerase chain reaction (PCR)-DNA sequencing approach was utilized for targeting the exon (and intron) 9 of the Hermansky-Pudlak syndrome type 4 (HPS4) gene. DNAs were extracted from peripheral blood of nine schizophrenic patients and one normal individual prior to PCR-DNA sequencing. Following DNA sequencing, a SNP (A>G) which is rs713998 at nucleotide position 22618 of exon 9 of the HPS4 gene was observed in eight schizophrenia samples. Moreover, DNA sequencing results also revealed an intronic aberration/SNP which is rs3747129 (C>T) at nucleotide position 22789 of intron 9 of the HPS4 gene in four schizophrenia samples. A SNP which is rs739289 (G>T) at nucleotide position 22677 of the intron was also found in eight schizophrenia samples. The importance of both the exonic and intronic aberrations is yet to be confirmed with further research involving larger population and other relevant clinical parameters. That notwithstanding, these preliminary results suggested that single nucleotide aberrations, particularly SNPs might have a role in the development of schizophrenia
    Matched MeSH terms: Sequence Analysis, DNA
  6. The prehistoric peopling of Southeast Asia
    McColl H, Racimo F, Vinner L, Demeter F, Gakuhari T, Moreno-Mayar JV, et al.
    Science, 2018 07 06;361(6397):88-92.
    PMID: 29976827 DOI: 10.1126/science.aat3628
    The human occupation history of Southeast Asia (SEA) remains heavily debated. Current evidence suggests that SEA was occupied by Hòabìnhian hunter-gatherers until ~4000 years ago, when farming economies developed and expanded, restricting foraging groups to remote habitats. Some argue that agricultural development was indigenous; others favor the "two-layer" hypothesis that posits a southward expansion of farmers giving rise to present-day Southeast Asian genetic diversity. By sequencing 26 ancient human genomes (25 from SEA, 1 Japanese Jōmon), we show that neither interpretation fits the complexity of Southeast Asian history: Both Hòabìnhian hunter-gatherers and East Asian farmers contributed to current Southeast Asian diversity, with further migrations affecting island SEA and Vietnam. Our results help resolve one of the long-standing controversies in Southeast Asian prehistory.
    Matched MeSH terms: Sequence Analysis, DNA
  7. Fulltext The next generation sequencing technologies
    MOHAMAD, O., HO, W. S.
    Buletin Persatuan Genetik Malaysia, 2011;18(1):33-35.
    MyJurnal
    Sanger sequencing has been the major method in directly sequencing DNA, and has dominated the DNA sequencing market for nearly past 30 years (Varshney et al., 2009). Along with PCR, we cannot underestimate how important this technology has been to research in various elds of molecular biology. It has revolutionized genetics by allowing us to gain unprecedented insights into the
    workings of different organisms.
    Matched MeSH terms: Sequence Analysis, DNA
  8. The molecular phylogenetic signature of Bali cattle revealed by maternal and paternal markers
    Syed-Shabthar SM, Rosli MK, Mohd-Zin NA, Romaino SM, Fazly-Ann ZA, Mahani MC, et al.
    Mol Biol Rep, 2013 Aug;40(8):5165-76.
    PMID: 23686165 DOI: 10.1007/s11033-013-2619-y
    Bali cattle is a domestic cattle breed that can be found in Malaysia. It is a domestic cattle that was purely derived from a domestication event in Banteng (Bos javanicus) around 3,500 BC in Indonesia. This research was conducted to portray the phylogenetic relationships of the Bali cattle with other cattle species in Malaysia based on maternal and paternal lineage. We analyzed the cytochrome c oxidase I (COI) mitochondrial gene and SRY of Y chromosome obtained from five species of the Bos genus (B. javanicus, Bos gaurus, Bos indicus, Bos taurus, and Bos grunniens). The water buffalo (Bubalus bubalis) was used as an outgroup. The phylogenetic relationships were observed by employing several algorithms: Neighbor-Joining (PAUP version 4.0), Maximum parsimony (PAUP version 4.0) and Bayesian inference (MrBayes 3.1). Results from the maternal data showed that the Bali cattle formed a monophyletic clade, and together with the B. gaurus clade formed a wild cattle clade. Results were supported by high bootstrap and posterior probability values together with genetic distance data. For the paternal lineage, the sequence variation is low (with parsimony informative characters: 2/660) resulting an unresolved Neighbor-Joining tree. However, Bali cattle and other domestic cattle appear in two monophyletic clades distinct from yak, gaur and selembu. This study expresses the potential of the COI gene in portraying the phylogenetic relationships between several Bos species which is important for conservation efforts especially in decision making since cattle is highly bred and hybrid breeds are often formed. Genetic conservation for this high quality beef cattle breed is important by maintaining its genetic characters to prevent extinction or even decreased the genetic quality.
    Matched MeSH terms: Sequence Analysis, DNA
  9. The mitogenome of Pangasius sutchi (Teleostei, Siluriformes: Pangasiidae)
    Zhao H, Kong X, Zhou C
    Mitochondrial DNA, 2014 Oct;25(5):342-4.
    PMID: 23795847 DOI: 10.3109/19401736.2013.800492
    The Pangasius sutchi is an important ornamental and economic fish in Southeast Asia e.g. Thailand, Malaysia and China. The complete mitochondrial genome sequence of P. sutchi has been sequenced, which contains 22 tRNA genes, 13 protein-coding genes, 2 rRNA genes and a non-coding control region with the total length of 16,522 bp. The gene order and composition are similar to most of other vertebrates. Just like most other vertebrates, the bias of G and C was found in different region/genes statistics results. Most of the genes are encoded on heavy strand, except for eight tRNA and ND6 genes. The mitogenome sequence of P. sutchi would contribute to better understand population genetics, evolution of this lineage.
    Matched MeSH terms: Sequence Analysis, DNA/methods*
  10. The mitochondrial 16 s rRNA reveals high anthropogenic influence on land snail diversity in a preliminary island survey
    Abu-Bakar SB, Razali NM, Naggs F, Wade C, Mohd-Nor SA, Aileen-Tan SH
    Mol Biol Rep, 2014 Mar;41(3):1799-805.
    PMID: 24443224 DOI: 10.1007/s11033-014-3029-5
    A total of 30 specimens belonging to five species, namely; Cryptozona siamensis, Sarika resplendens and Sarika sp. from the family Ariophantidae as well as Quantula striata and Quantula sp. from the family Dyakiidae were collected from the Langkawi Island in Northern Peninsular Malaysia. All specimens were identified through comparisons of shell morphology and amplification of a 500 bp segment of the 16S rRNA mtDNA gene. To assess phylogenetic insights, the sequences were aligned using ClustalW and phylogenetic trees were constructed. The analyses showed two major lineages in both Maximum Parsimony and Neighbour Joining phylogenetic trees. Each putative taxonomic group formed a monophyletic cluster. Our study revealed low species and intraspecies genetic diversities based on the 16S rRNA gene sequences. Thus, this study has provided an insight of land snail diversity in populations of an island highly influenced by anthropogenic activities through complementary use of shell morphological and molecular data.
    Matched MeSH terms: Sequence Analysis, DNA
  11. Fulltext The indonesian variants of CRF33_01B: Near-full length sequence analysis
    SahBandar IN, Takahashi K, Motomura K, Djoerban Z, Firmansyah I, Kitamura K, et al.
    AIDS Res Hum Retroviruses, 2011 Jan;27(1):97-102.
    PMID: 20958201 DOI: 10.1089/aid.2010.0163
    Cocirculation of subtype B and CRF01_AE in Southeast Asia has led to the establishment of new recombinant forms. In our previous study, we found five samples suspected of being recombinants between subtype B and CRF01_AE, and here, we analyzed near full-length sequences of two samples and compared them to known CRFs_01B, subtype B, and CRF01_AE. Five overlapped segments were amplified with nested PCR from PBMC DNA, sequenced, and analyzed for genome mosaicism. The two Indonesian samples, 07IDJKT189 and 07IDJKT194, showed genome-mosaic patterns similar to CRF33_01B references from Malaysia, with one short segment in the 3' end of the p31 integrase-coding region, which was rather more similar to subtype B than CRF01_AE, consisting of unclassified sequences. These results suggest gene-specific continuous diversification and spread of the CRF33_01B genomes in Southeast Asia.
    Matched MeSH terms: Sequence Analysis, DNA
  12. The geography of diversification in mutualistic ants: a gene's-eye view into the Neogene history of Sundaland rain forests
    Quek SP, Davies SJ, Ashton PS, Itino T, Pierce NE
    Mol Ecol, 2007 May;16(10):2045-62.
    PMID: 17498231
    We investigate the geographical and historical context of diversification in a complex of mutualistic Crematogaster ants living in Macaranga trees in the equatorial rain forests of Southeast Asia. Using mitochondrial DNA from 433 ant colonies collected from 32 locations spanning Borneo, Malaya and Sumatra, we infer branching relationships, patterns of genetic diversity and population history. We reconstruct a time frame for the ants' diversification and demographic expansions, and identify areas that might have been refugia or centres of diversification. Seventeen operational lineages are identified, most of which can be distinguished by host preference and geographical range. The ants first diversified 16-20 Ma, not long after the onset of the everwet forests in Sundaland, and achieved most of their taxonomic diversity during the Pliocene. Pleistocene demographic expansions are inferred for several of the younger lineages. Phylogenetic relationships suggest a Bornean cradle and major axis of diversification. Taxonomic diversity tends to be associated with mountain ranges; in Borneo, it is greatest in the Crocker Range of Sabah and concentrated also in other parts of the northern northwest coast. Within-lineage genetic diversity in Malaya and Sumatra tends to also coincide with mountain ranges. A series of disjunct and restricted distributions spanning northern northwest Borneo and the major mountain ranges of Malaya and Sumatra, seen in three pairs of sister lineages, further suggests that these regions were rain-forest refuges during drier climatic phases of the Pleistocene. Results are discussed in the context of the history of Sundaland's rain forests.
    Matched MeSH terms: Sequence Analysis, DNA
  13. The genetic characteristics and evolution of Tembusu virus
    Lei W, Guo X, Fu S, Feng Y, Tao X, Gao X, et al.
    Vet Microbiol, 2017 Mar;201:32-41.
    PMID: 28284620 DOI: 10.1016/j.vetmic.2017.01.003
    BACKGROUND: Since the turn of the 21st century, there have been several epidemic outbreaks of poultry diseases caused by Tembusu virus (TMUV). Although multiple mosquito and poultry-derived strains of TMUV have been isolated, no data exist about their comparative study, origin, evolution, and dissemination.

    METHODOLOGY: Parallel virology was used to investigate the phenotypes of duck and mosquito-derived isolates of TMUV. Molecular biology and bioinformatics methods were employed to investigate the genetic characteristics and evolution of TMUV.

    PRINCIPAL FINDINGS: The plaque diameter of duck-derived isolates of TMUV was larger than that of mosquito-derived isolates. The cytopathic effect (CPE) in mammalian cells occurred more rapidly induced by duck-derived isolates than by mosquito-derived isolates. Furthermore, duck-derived isolates required less time to reach maximum titer, and exhibited higher viral titer. These findings suggested that poultry-derived TMUV isolates were more invasive and had greater expansion capability than the mosquito-derived isolates in mammalian cells. Variations in amino acid loci in TMUV E gene sequence revealed two mutated amino acid loci in strains isolated from Malaysia, Thailand, and Chinese mainland compared with the prototypical strain of the virus (MM1775). Furthermore, TMUV isolates from the Chinese mainland had six common variations in the E gene loci that differed from the Southeast Asian strains. Phylogenetic analysis indicated that TMUV did not exhibit a species barrier in avian species and consisted of two lineages: the Southeast Asian and the Chinese mainland lineages. Molecular traceability studies revealed that the recent common evolutionary ancestor of TMUV might have appeared before 1934 and that Malaysia, Thailand and Shandong Province of China represent the three main sources related to TMUV spread.

    CONCLUSIONS: The current broad distribution of TMUV strains in Southeast Asia and Chinese mainland exhibited longer-range diffusion and larger-scale propagation. Therefore, in addition to China, other Asian and European countries linked to Asia have used improved measures to detect and monitor TMUV related diseases to prevent epidemics in poultry.

    Matched MeSH terms: Sequence Analysis, DNA/veterinary
  14. The first riparian skink (Genus: Sphenomorphus Strauch, 1887) from Peninsular Malaysia and its relationship to other Indochinese and Sundaic species
    Sumarli A, Grismer LL, Wood PL, Ahmad AB, Rizal S, Ismail LH, et al.
    Zootaxa, 2016 Oct 02;4173(1):29-44.
    PMID: 27701201 DOI: 10.11646/zootaxa.4173.1.3
    Recently discovered populations of skinks of the genus Sphenomorphus from central Peninsular Malaysia represent a new species, S. sungaicolus sp. nov., and the first riparian skink known from Peninsular Malaysia. Morphological analyses of an earlier specimen reported as S. tersus from the Forest Research Institute of Malaysia (FRIM), Selangor indicate that it too is the new riparian species S. sungaicolus sp. nov. Additionally, two specimens from the Tembat Forest Reserve, Hulu Terengganu, Kelantan and another from Ulu Gombak, Selangor have been diagnosed as new the species. The latter specimen remained unidentified in the Bernice Pauahi Bishop Museum, Honolulu, Hawaii since its collection in June 1962. Morphological and molecular analyses demonstrate that S. sungaicolus sp. nov. forms a clade with the Indochinese species S. maculatus, S. indicus, and S. tersus and is the sister species of the latter. Sphenomorphus sungaicolus sp. nov. can be differentiated from all other members of this clade by having a smaller SVL (66.5-89.6 mm); 39-44 midbody scale rows; 72-81 paravertebral scales; 74-86 ventral scales; a primitive plantar scale arrangement; and 20-22 scale rows around the tail at the position of the 10th subcaudal.
    Matched MeSH terms: Sequence Analysis, DNA
  15. The evolving molecular epidemiology of HIV type 1 among injecting drug users (IDUs) in Malaysia
    Tee KK, Saw TL, Pon CK, Kamarulzaman A, Ng KP
    AIDS Res Hum Retroviruses, 2005 Dec;21(12):1046-50.
    PMID: 16379608
    Earlier studies in the 1990s indicate that human immunodeficiency virus type 1 (HIV-1) subtype B has been the predominant subtype among injecting drug users (IDUs) in Malaysia. More recent studies performed between 2003 and 2004, however, show a high prevalence of unique CRF01_AE/B intersubtype recombinants among IDUs. To determine the subtype distribution among IDUs in Kuala Lumpur prior to the emergence of CRF01_AE/B intersubtype recombinants, the gag-pol or the reverse transcriptase gene was sequenced from IDUs who were diagnosed as HIV positive between 1993 and 2002. Subtype B was present at 50.0% followed by CRF01_AE/B recombinant at 41.7%, with more CRF01_AE/B recombinants detected between 2000 and 2002. All CRF01_AE/B recombinants shared similar recombination patterns. Interestingly, we found that this potential new candidate of circulating recombinant form (CRF) could have emerged as early as the mid-1990s. The results showed evidence of changing HIV-1 molecular epidemiology toward the predominance of CRF01_AE/B intersubtype recombinants among IDUs in Kuala Lumpur.
    Matched MeSH terms: Sequence Analysis, DNA
  16. The evolutionary origins of Southeast Asian Ovalocytosis
    Paquette AM, Harahap A, Laosombat V, Patnode JM, Satyagraha A, Sudoyo H, et al.
    Infect Genet Evol, 2015 Aug;34:153-9.
    PMID: 26047685 DOI: 10.1016/j.meegid.2015.06.002
    Southeast Asian Ovalocytosis (SAO) is a common red blood cell disorder that is maintained as a balanced polymorphism in human populations. In individuals heterozygous for the SAO-causing mutation there are minimal detrimental effects and well-documented protection from severe malaria caused by Plasmodium vivax and Plasmodium falciparum; however, the SAO-causing mutation is fully lethal in utero when homozygous. The present-day high frequency of SAO in Island Southeast Asia indicates the trait is maintained by strong heterozygote advantage. Our study elucidates the evolutionary origin of SAO by characterizing DNA sequence variation in a 9.5 kilobase region surrounding the causal mutation in the SLC4A1 gene. We find substantial haplotype diversity among SAO chromosomes and estimate the age of the trait to be approximately 10,005 years (95% CI: 4930-23,200 years). This date is far older than any other human malaria-resistance trait examined previously in Southeast Asia, and considerably pre-dates the widespread adoption of agriculture associated with the spread of speakers of Austronesian languages some 4000 years ago. Using a genealogy-based method we find no evidence of historical positive selection acting on SAO (s=0.0, 95% CI: 0.0-0.03), in sharp contrast to the strong present-day selection coefficient (e.g., 0.09) estimated from the frequency of this recessively lethal trait. This discrepancy may be due to a recent increase in malaria-driven selection pressure following the spread of agriculture, with SAO targeted as a standing variant by positive selection in malarial populations.
    Matched MeSH terms: Sequence Analysis, DNA
  17. Fulltext The effects of daily fasting hours on shaping gut microbiota in mice
    Li L, Su Y, Li F, Wang Y, Ma Z, Li Z, et al.
    BMC Microbiol, 2020 03 24;20(1):65.
    PMID: 32209070 DOI: 10.1186/s12866-020-01754-2
    BACKGROUND: It has recently been reported that intermittent fasting shapes the gut microbiota to benefit health, but this effect may be influenced to the exact fasting protocols. The purpose of this study was to assess the effects of different daily fasting hours on shaping the gut microbiota in mice. Healthy C57BL/6 J male mice were subjected to 12, 16 or 20 h fasting per day for 1 month, and then fed ad libitum for an extended month. Gut microbiota was analyzed by 16S rRNA gene-based sequencing and food intake was recorded as well.

    RESULTS: We found that cumulative food intake was not changed in the group with 12 h daily fasting, but significantly decreased in the 16 and 20 h fasting groups. The composition of gut microbiota was altered by all these types of intermittent fasting. At genus level, 16 h fasting led to increased level of Akkermansia and decreased level of Alistipes, but these effects disappeared after the cessation of fasting. No taxonomic differences were identified in the other two groups.

    CONCLUSIONS: These data indicated that intermittent fasting shapes gut microbiota in healthy mice, and the length of daily fasting interval may influence the outcome of intermittent fasting.

    Matched MeSH terms: Sequence Analysis, DNA/methods*
  18. Fulltext The dnd operon for DNA phosphorothioation modification system in Escherichia coli is located in diverse genomic islands
    Ho WS, Ou HY, Yeo CC, Thong KL
    BMC Genomics, 2015;16:199.
    PMID: 25879448 DOI: 10.1186/s12864-015-1421-8
    Strains of Escherichia coli that are non-typeable by pulsed-field gel electrophoresis (PFGE) due to in-gel degradation can influence their molecular epidemiological data. The DNA degradation phenotype (Dnd(+)) is mediated by the dnd operon that encode enzymes catalyzing the phosphorothioation of DNA, rendering the modified DNA susceptible to oxidative cleavage during a PFGE run. In this study, a PCR assay was developed to detect the presence of the dnd operon in Dnd(+) E. coli strains and to improve their typeability. Investigations into the genetic environments of the dnd operon in various E. coli strains led to the discovery that the dnd operon is harboured in various diverse genomic islands.
    Matched MeSH terms: Sequence Analysis, DNA
  19. The distribution of hepatitis B virus genotypes in Thailand
    Louisirirotchanakul S, Olinger CM, Arunkaewchaemsri P, Poovorawan Y, Kanoksinsombat C, Thongme C, et al.
    J Med Virol, 2012 Oct;84(10):1541-7.
    PMID: 22930500 DOI: 10.1002/jmv.23363
    Phylogenetic analysis was performed on hepatitis B virus (HBV) strains obtained from 86 hepatitis B surface antigen (HBsAg) positive donors from Thailand originating throughout the country. Based on the S gene, 87.5% of strains were of genotype C while 10.5% were of genotype B, with all genotype B strains obtained from patients originating from the central or the south Thailand. No genotype B strains were found in the north of Thailand. Surprisingly, one patient was infected with a genotype H strain while another patient was infected with a genotype G strain. Complete genome sequencing and recombination analysis identified the latter as being a genotype G and C2 recombinant with the breakpoint around nucleotide position 700. The origin of the genotype G fragment was not identifiable while the genotype C2 fragment most likely came from strains circulating in Laos or Malaysia. The performance of different HBsAg diagnostic kits and HBV nucleic acid amplification technology (NAT) was evaluated. The genotype H and G/C2 recombination did not interfere with HBV detection.
    Matched MeSH terms: Sequence Analysis, DNA
  20. The complex phylogeography of the Indo-Malayan Alophoixus bulbuls with the description of a putative new ring species complex
    Fuchs J, Ericson PG, Bonillo C, Couloux A, Pasquet E
    Mol Ecol, 2015 Nov;24(21):5460-74.
    PMID: 26224534 DOI: 10.1111/mec.13337
    The Indo-Malayan bioregion has provided some of the most spectacular discoveries of new vertebrate species (e.g. saola, khanyou, bare-faced bulbul) over the last 25 years. Yet, very little is known about the processes that led to the current biodiversity in this region. We reconstructed the phylogeographic history of a group of closely related passerines, the Alophoixus bulbuls. These birds are continuously distributed in Indo-Malaya around the Thailand lowlands such that their distribution resembles a ring. Our analyses revealed a single colonization event of the mainland from Sundaland with sequential divergence of taxa from southwest to northeast characterized by significant gene flow between parapatric taxa, and reduced or ancient gene flow involving the two taxa at the extremities of the ring. We detected evidence of population expansion in two subspecies, including one that was involved in the closing of the ring. Hence, our analyses indicate that the diversification pattern of Alophoixus bulbuls fits a ring species model driven by geographic isolation. To our knowledge, the Alophoixus bulbuls represent the first case of a putative broken ring species complex in Indo-Malaya. We also discuss the implications of our results on our understanding of the biogeography in Indo-Malaya.
    Matched MeSH terms: Sequence Analysis, DNA
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