MyMedR

A single, large deletion accounts for all the beta-globin gene mutations in twenty families from Sabah (North Borneo), Malaysia. Mutation in brief no. 240. Online

Thong MK, Rudzki Z, Hall J, Tan JA, Chan LL, Yap SF

Hum Mutat, 1999;13(5):413.

PMID: 10338100 DOI: 10.1002/(SICI)1098-1004(1999)13:5<413::AID-HUMU15>

Beta-thalassemia major is one of the commonest genetic disorders in South-East Asia. The spectrum of beta-thalassemia mutations in the various ethnic sub-populations on the island of Borneo is unknown. We studied 20 Dusun children from the East Malaysian state of Sabah (North Borneo) with a severe beta-thalassemia major phenotype, using a combination of Southern analysis, polymerase chain reaction analysis and direct sequencing. We found the children to be homozygous for a large deletion, which has a 5' breakpoint at position -4279 from the cap site of the beta-globin gene (HBB) with the 3' breakpoint located in a L1 family of repetitive sequences at an unknown distance from the beta-globin gene. This was similar to a recent finding of a large deletion causing beta-thalassemia first described in unrelated beta-thalassemia heterozygotes of Filipino descent. This report describes the first 20 families with homozygosity of the deletion causing a severe phenotype. It provides the first information on the molecular epidemiology of beta-thalassemia in Sabah. This finding has implications for the population genetics and preventative strategies for beta-thalassemia major for nearly 300 million individuals in South-East Asia.

Matched MeSH terms: Sequence Analysis, DNA

Three new species of Physalacria from China, with a key to the Asian taxa

Qin J, Yang ZL

Mycologia, 2016 Jan-Feb;108(1):215-26.

PMID: 26553778 DOI: 10.3852/15-166

Three new and one previously described species of Physalacria (Physalacriaceae, Agaricales) are reported from China. Specimens of two additional species described from Malaysia and North America were studied for comparison. Placements of these species were corroborated based on morphological observations and molecular evidence from partial sequences of the nuc rDNA internal transcribed spacer regions (ITS) and the 28S D1-D3 region, and genes for translation elongation factor 1-α (tef1α) and the second largest subunit of RNA polymerase II (rpb2). These new species of Physalacria distributed in subtropical China were found on rotten wood of broadleaf trees or bamboo and possess stipitate-capitate basidiomata with four-spored basidia, clamp connections and smooth, inamyloid basidiospores. To facilitate studies of the genus in Asia, a key is provided for all Physalacria species reported from this region.

Matched MeSH terms: Sequence Analysis, DNA

A molecular epidemiological study targeting the glycoprotein gene of rabies virus isolates from China

Meng SL, Yan JX, Xu GL, Nadin-Davis SA, Ming PG, Liu SY, et al.

Virus Res, 2007 Mar;124(1-2):125-38.

PMID: 17129631

A group of 31 rabies viruses (RABVs), recovered primarily from dogs, one deer and one human case, were collected from various areas in China between 1989 and 2006. Complete G gene sequences determined for these isolates indicated identities of nucleotide and amino acid sequences of >or=87% and 93.8%, respectively. Phylogenetic analysis of these and some additional Chinese isolates clearly supported the placement of all Chinese viruses in Lyssavirus genotype 1 and divided all Chinese isolates between four distinct groups (I-IV). Several variants identified within the most commonly encountered group I were distributed according to their geographical origins. A comparison of representative Chinese viruses with other isolates retrieved world-wide indicated a close evolutionary relationship between China group I and II viruses and those of Indonesia while China group III viruses formed an outlying branch to variants from Malaysia and Thailand. China group IV viruses were closely related to several vaccine strains. The predicted glycoprotein sequences of these RABVs variants are presented and discussed with respect to the utility of the anti-rabies biologicals currently employed in China.

Matched MeSH terms: Sequence Analysis, DNA

Phylogeography of Tetrancistrum nebulosi (Monogenea, Dactylogyridae) on the host of mottled spinefoot (Siganus fuscescens) in the South China Sea, inferred from mitochondrial COI and ND2 genes

Wang M, Yan S, Brown CL, Shaharom-Harrison F, Shi SF, Yang TB

Mitochondrial DNA A DNA Mapp Seq Anal, 2016 11;27(6):3865-3875.

PMID: 25319302

To examine the phylogeographical pattern of Tetrancistrum nebulosi (Monogenea, Dactylogyridae) in the South China Sea, fragments of mitochondrial cytochrome c oxidase subunit I and NADH dehydrogenase subunit 2 genes were obtained for 220 individuals collected from 8 localities along the southeast coast of China and 1 locality in Terengganu, Malaysia. Based on these two genes, two and three distinct clades with geographic signals were revealed on the phylogenetic trees respectively. The divergence between these clades was estimated to occur in the late Pleistocene. Analysis of molecular variance and pairwise FSTsuggested a high rate of gene flow among individuals sampled from the Chinese coast, but with obvious genetic differentiation from the Malaysian population. Mismatch distribution and neutrality tests indicated that the T. nebulosi population experienced expansion in Pleistocene low sea level periods. Vicariance was considered to account for the genetic divergence between Chinese and Malaysian populations, while sea level fluctuations and mainland-island connections during glacial cycles were associated with the slight genetic divergence between the populations along the mainland coast of China and those off Sanya. On the contrary, oceanographic circulations and host migration could lead to genetic homogeneity of populations distributed along the mainland coast of China.

Matched MeSH terms: Sequence Analysis, DNA/veterinary

Sphingopyxis microcysteis sp. nov., a novel bioactive exopolysaccharides-bearing Sphingomonadaceae isolated from the Microcystis phycosphere

Zhang XL, Li GX, Ge YM, Iqbal NM, Yang X, Cui ZD, et al.

Antonie Van Leeuwenhoek, 2021 Jun;114(6):845-857.

PMID: 33770293 DOI: 10.1007/s10482-021-01563-1

During the study into the microbial biodiversity and bioactivity of the Microcystis phycosphere, a new yellow-pigmented, non-motile, rod-shaped bacterium containing polyhydroxybutyrate granules designated as strain Z10-6T was isolated from highly-toxic Microcystis aeruginosa Kützing M.TN-2. The new isolate produces active bioflocculating exopolysaccharides. Phylogenetic analysis based on 16S rRNA gene sequences indicated strain Z10-6T belongs to the genus Sphingopyxis with highest similarity to Sphingopyxis solisilvae R366T (98.86%), and the similarity to other Sphingopyxis members was less than 98.65%. However, both low values obtained by phylogenomic calculation of average nucleotide identity (ANI, 85.5%) and digital DNA-DNA hybridization (dDDH, 29.8%) separated the new species from its closest relative. The main polar lipids were sphingoglycolipid, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, one unidentified glycolipid and one unidentified aminophospholipid. The predominant fatty acids were summed feature 8, C17:1ω6c, summed feature 3, C16:0, C18:1ω7c 11-methyl and C14:0 2-OH. The respiratory quinone was ubiqunone-10, with spermidine as the major polyamine. The genomic DNA G + C content was 64.8 mol%. Several biosynthesis pathways encoding for potential new bacterial bioactive metabolites were found in the genome of strain Z10-6T. The polyphasic analyses clearly distinguished strain Z10-6T from its closest phylogenetic neighbors. Thus, it represents a novel species of the genus Sphingopyxis, for which the name Sphingopyxis microcysteis sp. nov. is proposed. The type strain is Z10-6T (= CCTCC AB2017276T = KCTC 62492T).

Matched MeSH terms: Sequence Analysis, DNA

Identification of a novel HLA-A*01 variant, HLA-A*01:211, in a Singaporean Malay bone marrow donor

Kaur A, Cho L, Cereb N, Lin PY, Yang KL

HLA, 2020 09;96(3):329-330.

PMID: 32227684 DOI: 10.1111/tan.13884

One nucleotide substitution in codon 73 of HLA-A*01:01:01:01 results in a novel allele, HLA-A*01:211.

Matched MeSH terms: Sequence Analysis, DNA

HLA-B*15:349:02, a novel variant of HLA-B*15, discovered in a Singaporean Malay bone marrow donor

Cho L, Kaur A, Cereb N, Lin PY, Yang KL

HLA, 2020 09;96(3):344-345.

PMID: 32212215 DOI: 10.1111/tan.13879

One nucleotide substitution in codon 112 of HLA-B*15:349:01 results in a novel allele, HLA-B*15:349:02.

Matched MeSH terms: Sequence Analysis, DNA

HLA-DQB1*06:132, an HLA-DQB1*06 variant, discovered in a Singaporean Malay bone marrow donor

Cho L, Kaur A, Cereb N, Lin PY, Yang KL

HLA, 2020 08;96(2):243-244.

PMID: 32250029 DOI: 10.1111/tan.13889

One nucleotide substitution in codon 38 of HLA-DQB1*06:01:01:01 results in a novel allele, HLA-DQB1*06:132.

Matched MeSH terms: Sequence Analysis, DNA

HLA-B*38:64, an HLA-B*38 variant, detected in a Singaporean Malay unrelated hematopoietic stem cell donor

Cho L, Kaur A, Cereb N, Lin PY, Yang KL

HLA, 2020 08;96(2):217-218.

PMID: 32227685 DOI: 10.1111/tan.13873

One nucleotide substitution in codon 89 of HLA-B*38:02:01:01 results in a novel allele, HLA-B*38:64.

Matched MeSH terms: Sequence Analysis, DNA

Discovery of HLA-B*35:368, a novel HLA-B*35 variant, in a Singaporean Malay hematopoietic stem cell donor

Kaur A, Cho L, Cereb N, Lin PY, Yang KL

HLA, 2020 07;96(1):94-95.

PMID: 32166893 DOI: 10.1111/tan.13862

DNA substitutions from codons 69 to 71 of HLA-B*35:05:01:01 result in a novel allele, HLA-B*35:368.

Matched MeSH terms: Sequence Analysis, DNA

Fulltext Mass spectrometry-based identification and whole-genome characterisation of the first pteropine orthoreovirus isolated from monkey faeces in Thailand

Kosoltanapiwat N, Reamtong O, Okabayashi T, Ampawong S, Rungruengkitkun A, Thiangtrongjit T, et al.

BMC Microbiol, 2018 10 17;18(1):135.

PMID: 30332986 DOI: 10.1186/s12866-018-1302-9

BACKGROUND: The pteropine orthoreovirus (PRV) was isolated from monkey (Macaca fascicularis) faecal samples collected from human-inhabited areas in Lopburi Province, Thailand. These samples were initially obtained to survey for the presence of hepatitis E virus (HEV).

RESULTS: Two virus isolates were retrieved by virus culture of 55 monkey faecal samples. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was successfully used to identify the viruses as the segmented dsRNA orthoreovirus. Phylogenetic analysis of the Lopburi orthoreovirus whole-genomes revealed relationships with the well-characterised PRVs Pulau (segment L1), Cangyuan (segments L2, M3 and S3), Melaka (segments L3 and M2), Kampar (segments M1 and S2) and Sikamat (segments S1 and S4) of Southeast Asia and China with nucleotide sequence identities of 93.5-98.9%. RT-PCR showed that PRV was detected in 10.9% (6/55) and HEV was detected in 25.5% (14/55) of the monkey faecal samples.

CONCLUSIONS: PRV was isolated from monkey faeces for the first time in Thailand via viral culture and LC-MS/MS. The genetic diversity of the virus genome segments suggested a re-assortment within the PRV species group. The overall findings emphasise that monkey faeces can be sources of zoonotic viruses, including PRV and HEV, and suggest the need for active virus surveillance in areas of human and monkey co-habitation to prevent and control emerging zoonotic diseases in the future.

Matched MeSH terms: Sequence Analysis, DNA

Genome structure of Sagiyama virus and its relatedness to other alphaviruses

Shirako Y, Yamaguchi Y

J Gen Virol, 2000 May;81(Pt 5):1353-60.

PMID: 10769079

Sagiyama virus (SAG) is a member of the genus Alphavirus in the family Togaviridae, isolated in Japan from mosquitoes in 1956. We determined the complete nucleotide sequence of the SAG genomic RNA from the original stock virus which formed a mixture of plaques with different sizes, and that from a full-length cDNA clone, pSAG2, infectious RNA transcripts from which formed uniform large plaques on BHK-21 cells. The SAG genome was 11698 nt in length exclusive of the 3' poly(A) tail. Between the complete nucleotide sequences of the full-length cDNA clone, pSAG2, and the consensus sequence from the original stock virus, there were nine amino acid differences; two each in nsP1, nsP2 and E1, and three in E2, some of which may be responsible for plaque phenotypic variants in the original virus stock. SAG was most closely related to Ross River virus among other alphaviruses fully sequenced, with amino acid sequence identities of 86% in the nonstructural proteins and of 83% in the structural proteins. The 3' terminal 280 nt region of SAG was 82% identical to that of Barmah Forest virus, which was otherwise not closely related to SAG. Comparison of the nucleotide sequence of SAG with partial nucleotide sequences of Getah virus (GET), which was originally isolated in Malaysia in 1955 and is closely related to SAG in serology and in biology, showed near identity between the two viruses, suggesting that SAG is a strain of GET.

Matched MeSH terms: Sequence Analysis, DNA

PCR cycle sequencing protocol for population mitochondrial cytochrome b analysis

Lau CH, Yusoff K, Tan SG, Yamada Y

Biotechniques, 1995 Feb;18(2):262-6.

PMID: 7727128

Laboratories intending to adopt cycle sequencing of PCR products in their routine analysis often face a confusing range of methods and kits. Through the study of mitochondrial cytochrome b, we have shown that clean and highly reproducible sequences could be obtained by using a combination of existing simple and economical methods in the preparation of DNA templates, PCR, purification of PCR products and sequencing. Our protocol is useful in itself or as a standard in typing other PCR-amplified DNA at the population level.

Matched MeSH terms: Sequence Analysis, DNA/methods*

Fulltext Genome sequence of Hydrogenophaga sp. strain PBC, a 4-aminobenzenesulfonate-degrading bacterium

Gan HM, Chew TH, Tay YL, Lye SF, Yahya A

J Bacteriol, 2012 Sep;194(17):4759-60.

PMID: 22887664 DOI: 10.1128/JB.00990-12

Hydrogenophaga sp. strain PBC is an effective degrader of 4-aminobenzenesulfonate isolated from textile wastewater. Here we present the assembly and annotation of its genome, which may provide further insights into its metabolic potential. This is the first announcement of the draft genome sequence of a strain from the genus Hydrogenophaga.

Matched MeSH terms: Sequence Analysis, DNA

Fulltext Genome sequence of Ralstonia sp. strain PBA, a bacterium involved in the biodegradation of 4-aminobenzenesulfonate

Gan HM, Chew TH, Tay YL, Lye SF, Yahya A

J Bacteriol, 2012 Sep;194(18):5139-40.

PMID: 22933765 DOI: 10.1128/JB.01165-12

Ralstonia sp. strain PBA was isolated from textile wastewater in a coculture with Hydrogenophaga sp. strain PBC. Here we present the assembly and annotation of its genome, which may provide further insights into the mechanism of its interaction with strain PBC during 4-aminobenzenesulfonate degradation.

Matched MeSH terms: Sequence Analysis, DNA*

Fulltext Molecular cloning, sequence analysis and developmental stage expression of a putative septin gene fragment from Aedes albopictus (Diptera: Culicidae)

Avicor SW, Wajidi MF, Jaal Z, Yahaya ZS

Acta Biochim. Pol., 2016;63(2):243-6.

PMID: 27059016 DOI: 10.18388/abp.2014_909

Septins belong to GTPases that are involved in vital cellular activities, including cytokinesis. Although present in many organisms, they are yet to be isolated from Aedes albopictus. This study reports for the first time on a serendipitous isolation of a partial septin sequence from Ae. albopictus and its developmental expression profile. The Ae. albopictus partial septin sequence contains 591 nucleotides encoding 197 amino acids. It shares homology with several insect septin genes and has a close phylogenetic relationship with Aedes aegypti and Culex quinquefasciatus septins. The Ae. albopictus septin fragment was differentially expressed in the mosquito's developmental stages, with an increased expression in the adults.

Matched MeSH terms: Sequence Analysis, DNA

Fulltext Helicobacter pylori cagA gene variants in Malaysians of different ethnicity

Mohamed R, Hanafiah A, Rose IM, Manaf MR, Abdullah SA, Sagap I, et al.

Eur J Clin Microbiol Infect Dis, 2009 Jul;28(7):865-9.

PMID: 19247698 DOI: 10.1007/s10096-009-0712-x

We have defined DNA repeat variability in the 3'-terminus of the cagA gene of Helicobacter pylori strains from Malaysian patients of different ethnicities. We identified different alleles based on the EPIYA repeats. cagA types A-B-D and A-B-B-D are more similar to the sequence of Japanese strains, whereas cagA types A-B-C, A-B-C-C, A-B and A-C displayed similarity to strain 26695 sequences. A significant association was found between cagA genotypes and patients' ethnicity, with cagA type A-B-D being predominantly isolated from Chinese patients and cagA type A-B-C from Malays and Indians. Our data further corroborate the possibility that variant biological activity of CagA may affect the host specificity and/or pathogenicity of H. pylori.

Matched MeSH terms: Sequence Analysis, DNA

Detection of human herpesvirus 7 in salivary glands

Yadav M, Nambiar S, Khoo SP, Yaacob HB

Arch Oral Biol, 1997 Aug;42(8):559-67.

PMID: 9347118

The prevalence and cellular distribution of human herpesvirus 7 (HHV-7) in archival labial salivary glands was analysed for virus-specific DNA sequences by polymerase chain reaction (PCR) and in situ hybridization signals. In addition, the cellular expression of HHV-7-encoded protein was detected by immunohistochemical staining with a virus-specific monoclonal antibody. Eleven of 20 samples were positive for the HHV-7 DNA sequence by PCR. Eighteen of 20 tissues analysed by in situ hybridization showed signals in ductal, serous and mucous cells. Some nuclei of these cells and also the myoepithelial population were positive. In immunolocalization studies, all 20 salivary glands consistently showed HHV-7-expressed protein in the cytoplasm of ductal cuboidal and columnar cells. The protein was also found in the cytoplasm of mucous and serous acinar cells that were immunopositive for HHV-7. The observations are consistent with the suggestion that the labial salivary gland is a site for virus replication, potential persistence and a source of infective HHV-7 in saliva.

Matched MeSH terms: Sequence Analysis, DNA

Fulltext Copy number variation arising from gene conversion on the human Y chromosome

Shi W, Massaia A, Louzada S, Banerjee R, Hallast P, Chen Y, et al.

Hum Genet, 2018 Jan;137(1):73-83.

PMID: 29209947 DOI: 10.1007/s00439-017-1857-9

We describe the variation in copy number of a ~ 10 kb region overlapping the long intergenic noncoding RNA (lincRNA) gene, TTTY22, within the IR3 inverted repeat on the short arm of the human Y chromosome, leading to individuals with 0-3 copies of this region in the general population. Variation of this CNV is common, with 266 individuals having 0 copies, 943 (including the reference sequence) having 1, 23 having 2 copies, and two having 3 copies, and was validated by breakpoint PCR, fibre-FISH, and 10× Genomics Chromium linked-read sequencing in subsets of 1234 individuals from the 1000 Genomes Project. Mapping the changes in copy number to the phylogeny of these Y chromosomes previously established by the Project identified at least 20 mutational events, and investigation of flanking paralogous sequence variants showed that the mutations involved flanking sequences in 18 of these, and could extend over > 30 kb of DNA. While either gene conversion or double crossover between misaligned sister chromatids could formally explain the 0-2 copy events, gene conversion is the more likely mechanism, and these events include the longest non-allelic gene conversion reported thus far. Chromosomes with three copies of this CNV have arisen just once in our data set via another mechanism: duplication of 420 kb that places the third copy 230 kb proximal to the existing proximal copy. Our results establish gene conversion as a previously under-appreciated mechanism of generating copy number changes in humans and reveal the exceptionally large size of the conversion events that can occur.

Matched MeSH terms: Sequence Analysis, DNA

Fulltext Molecular epidemiology of coxsackievirus A16: intratype and prevalent intertype recombination identified

Chen X, Tan X, Li J, Jin Y, Gong L, Hong M, et al.

PLoS One, 2013;8(12):e82861.

PMID: 24340064 DOI: 10.1371/journal.pone.0082861

Coxsackievirus A16 (CVA16) is responsible for nearly 50% of all the conﬁrmed hand, foot, and mouth disease (HFMD) cases in mainland China, sometimes it could also cause severe complications, and even death. To clarify the genetic characteristics and the epidemic patterns of CVA16 in mainland China, comprehensive bioinfomatics analyses were performed by using 35 CVA16 whole genome sequences from 1998 to 2011, 593 complete CVA16 VP1 sequences from 1981 to 2011, and prototype strains of human enterovirus species A (EV-A). Analysis on complete VP1 sequences revealed that subgenotypes B1a and B1b were prevalent strains and have been co-circulating in many Asian countries since 2000, especially in mainland China for at least 13 years. While the prevalence of subgenotype B1c (totally 20 strains) was much limited, only found in Malaysia from 2005 to 2007 and in France in 2010. Genotype B2 only caused epidemic in Japan and Malaysia from 1981 to 2000. Both subgenotypes B1a and B1b were potential recombinant viruses containing sequences from other EV-A donors in the 5'-untranslated region and P2, P3 non-structural protein encoding regions.

Matched MeSH terms: Sequence Analysis, DNA

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