Displaying publications 21 - 40 of 48 in total

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  1. Rani AQ, Malueka RG, Sasongko TH, Awano H, Lee T, Yagi M, et al.
    Mol Genet Metab, 2011 Jul;103(3):303-4.
    PMID: 21514860 DOI: 10.1016/j.ymgme.2011.04.002
    In Duchenne muscular dystrophy (DMD), identification of one nonsense mutation in the DMD gene has been considered an endpoint of genetic diagnosis. Here, we identified two closely spaced nonsense mutations in the DMD gene. In a Malaysian DMD patient two nonsense mutations (p.234S>X and p.249Q>X, respectively) were identified within exon 8. The proband's mother carried both mutations on one allele. Multiple mutations may explain the occasional discrepancies between genotype and phenotype in dystrophinopathy.
    Matched MeSH terms: Introns
  2. Ong-Abdullah M, Ordway JM, Jiang N, Ooi SE, Kok SY, Sarpan N, et al.
    Nature, 2015 Sep 24;525(7570):533-7.
    PMID: 26352475 DOI: 10.1038/nature15365
    Somaclonal variation arises in plants and animals when differentiated somatic cells are induced into a pluripotent state, but the resulting clones differ from each other and from their parents. In agriculture, somaclonal variation has hindered the micropropagation of elite hybrids and genetically modified crops, but the mechanism responsible remains unknown. The oil palm fruit 'mantled' abnormality is a somaclonal variant arising from tissue culture that drastically reduces yield, and has largely halted efforts to clone elite hybrids for oil production. Widely regarded as an epigenetic phenomenon, 'mantling' has defied explanation, but here we identify the MANTLED locus using epigenome-wide association studies of the African oil palm Elaeis guineensis. DNA hypomethylation of a LINE retrotransposon related to rice Karma, in the intron of the homeotic gene DEFICIENS, is common to all mantled clones and is associated with alternative splicing and premature termination. Dense methylation near the Karma splice site (termed the Good Karma epiallele) predicts normal fruit set, whereas hypomethylation (the Bad Karma epiallele) predicts homeotic transformation, parthenocarpy and marked loss of yield. Loss of Karma methylation and of small RNA in tissue culture contributes to the origin of mantled, while restoration in spontaneous revertants accounts for non-Mendelian inheritance. The ability to predict and cull mantling at the plantlet stage will facilitate the introduction of higher performing clones and optimize environmentally sensitive land resources.
    Matched MeSH terms: Introns/genetics
  3. Jarolim P, Palek J, Amato D, Hassan K, Sapak P, Nurse GT, et al.
    Proc Natl Acad Sci U S A, 1991 Dec 15;88(24):11022-6.
    PMID: 1722314
    Southeast Asian ovalocytosis (SAO) is a hereditary condition that is widespread in parts of Southeast Asia. The ovalocytic erythrocytes are rigid and resistant to invasion by various malarial parasites. We have previously found that the underlying defect in SAO involves band 3 protein, the major transmembrane protein, which has abnormal structure and function. We now report two linked mutations in the erythrocyte band 3 gene in SAO: (i) a deletion of codons 400-408 and (ii) a substitution, A----G, in the first base of codon 56 leading to substitution of Lys-56 by Glu-56. The first defect leads to a deletion of nine amino acids in the boundary of cytoplasmic and membrane domains of band 3. This defect has been detected in all 30 ovalocytic subjects from Malaysia, the Philippines, and two unrelated coastal regions of Papua New Guinea, whereas it was absent in all 30 controls from Southeast Asia and 20 subjects of different ethnic origin from the United States. The Lys-56----Glu substitution has likewise been found in all SAO subjects. However, it has also been detected in 5 of the 50 control subjects, suggesting that it represents a linked polymorphism. We conclude that the deletion of codons 400-408 in the band 3 gene constitutes the underlying molecular defect in SAO.
    Matched MeSH terms: Introns
  4. Coppard SE, Jessop H, Lessios HA
    Sci Rep, 2021 Aug 16;11(1):16568.
    PMID: 34400682 DOI: 10.1038/s41598-021-95872-0
    The sea urchins Echinothrix calamaris and Echinothrix diadema have sympatric distributions throughout the Indo-Pacific. Diverse colour variation is reported in both species. To reconstruct the phylogeny of the genus and assess gene flow across the Indo-Pacific we sequenced mitochondrial 16S rDNA, ATPase-6, and ATPase-8, and nuclear 28S rDNA and the Calpain-7 intron. Our analyses revealed that E. diadema formed a single trans-Indo-Pacific clade, but E. calamaris contained three discrete clades. One clade was endemic to the Red Sea and the Gulf of Oman. A second clade occurred from Malaysia in the West to Moorea in the East. A third clade of E. calamaris was distributed across the entire Indo-Pacific biogeographic region. A fossil calibrated phylogeny revealed that the ancestor of E. diadema diverged from the ancestor of E. calamaris ~ 16.8 million years ago (Ma), and that the ancestor of the trans-Indo-Pacific clade and Red Sea and Gulf of Oman clade split from the western and central Pacific clade ~ 9.8 Ma. Time since divergence and genetic distances suggested species level differentiation among clades of E. calamaris. Colour variation was extensive in E. calamaris, but not clade or locality specific. There was little colour polymorphism in E. diadema.
    Matched MeSH terms: Introns/genetics
  5. Forcina G, Camacho-Sanchez M, Tuh FYY, Moreno S, Leonard JA
    Heliyon, 2021 Jan;7(1):e05583.
    PMID: 33437884 DOI: 10.1016/j.heliyon.2020.e05583
    Background and aims: Wildlife conservation has focused primarily on species for the last decades. Recently, popular perception and laws have begun to recognize the central importance of genetic diversity in the conservation of biodiversity. How to incorporate genetic diversity in ongoing monitoring and management of wildlife is still an open question.

    Methods: We tested a panel of multiplexed, high-throughput sequenced introns in the small mammal communities of two UNESCO World Heritage Sites on different continents to assess their viability for large-scale monitoring of genetic variability in a spectrum of diverse species. To enhance applicability across other systems, the bioinformatic pipeline for primer design was outlined.

    Results: The number of loci amplified and amplification evenness decreased as phylogenetic distance increased from the reference taxa, yet several loci were still variable across multiple mammal orders.

    Conclusions: Genetic variability found is informative for population genetic analyses and for addressing phylogeographic and phylogenetic questions, illustrated by small mammal examples here.

    Matched MeSH terms: Introns
  6. Courage C, Oliver KL, Park EJ, Cameron JM, Grabińska KA, Muona M, et al.
    Am J Hum Genet, 2021 04 01;108(4):722-738.
    PMID: 33798445 DOI: 10.1016/j.ajhg.2021.03.013
    Progressive myoclonus epilepsies (PMEs) comprise a group of clinically and genetically heterogeneous rare diseases. Over 70% of PME cases can now be molecularly solved. Known PME genes encode a variety of proteins, many involved in lysosomal and endosomal function. We performed whole-exome sequencing (WES) in 84 (78 unrelated) unsolved PME-affected individuals, with or without additional family members, to discover novel causes. We identified likely disease-causing variants in 24 out of 78 (31%) unrelated individuals, despite previous genetic analyses. The diagnostic yield was significantly higher for individuals studied as trios or families (14/28) versus singletons (10/50) (OR = 3.9, p value = 0.01, Fisher's exact test). The 24 likely solved cases of PME involved 18 genes. First, we found and functionally validated five heterozygous variants in NUS1 and DHDDS and a homozygous variant in ALG10, with no previous disease associations. All three genes are involved in dolichol-dependent protein glycosylation, a pathway not previously implicated in PME. Second, we independently validate SEMA6B as a dominant PME gene in two unrelated individuals. Third, in five families, we identified variants in established PME genes; three with intronic or copy-number changes (CLN6, GBA, NEU1) and two very rare causes (ASAH1, CERS1). Fourth, we found a group of genes usually associated with developmental and epileptic encephalopathies, but here, remarkably, presenting as PME, with or without prior developmental delay. Our systematic analysis of these cases suggests that the small residuum of unsolved cases will most likely be a collection of very rare, genetically heterogeneous etiologies.
    Matched MeSH terms: Introns/genetics
  7. Tang K, Ngoi SM, Gwee PC, Chua JM, Lee EJ, Chong SS, et al.
    Pharmacogenetics, 2002 Aug;12(6):437-50.
    PMID: 12172212
    The MDR1 multidrug transporter plays a key role in determining drug bioavailability, and differences in drug response exist amongst different ethnic groups. Numerous studies have identified an association between the MDR1 single nucleotide polymorphism (SNP) exon 26 3435C>T and differences in MDR1 function. We performed a haplotype analysis of the MDR1 gene in three major ethnic groups (Chinese, Malays and Indians) by examining 10 intragenic SNPs. Four were polymorphic in all three ethnic groups: one occurring in the non-coding region and three occurring in coding exons. All three coding SNPs (exon 12 1236C>T, exon 21 2677G>T/A and exon 26 3435C>T) were present in high frequency in each ethnic group, and the derived haplotype profiles exhibited distinct differences between the groups. Fewer haplotypes were observed in the Malays (n = 6) compared to the Chinese (n = 10) and Indians (n = 9). Three major haplotypes (> 10% frequency) were observed in the Malays and Chinese; of these, two were observed in the Indians. Strong linkage disequilibrium (LD) was detected between the three SNPs in all three ethnic groups. The strongest LD was present in the Chinese, followed by Indians and Malays, with the corresponding LD blocks estimated to be approximately 80 kb, 60 kb and 40 kb, respectively. These data strongly support the hypothesis that strong LD between the neutral SNP exon 26 3435C>T and a nearby unobserved causal SNP underlies the observed associations between the neutral SNP and MDR1 functional differences. Furthermore, strong LD between exon 26 3435T and different unobserved causal SNPs in different study populations may provide a plausible explanation for conflicting reports associating the same exon 26 3435T allele with different MDR1 functional changes.
    Matched MeSH terms: Introns/genetics
  8. Yang W, Lee PP, Thong MK, Ramanujam TM, Shanmugam A, Koh MT, et al.
    Clin Genet, 2015 Dec;88(6):542-9.
    PMID: 25534311 DOI: 10.1111/cge.12553
    Familial multiple intestinal atresias is an autosomal recessive disease with or without combined immunodeficiency. In the last year, several reports have described mutations in the gene TTC7A as causal to the disease in different populations. However, exact correlation between different genotypes and various phenotypes are not clear. In this study, we report identification of novel compound heterozygous mutations in TTC7A gene in a Malay girl with familial multiple intestinal atresias and severe combined immunodeficiency (MIA-SCID) by whole exome sequencing. We found two mutations in TTC7A: one that destroyed a putative splicing acceptor at the junction of intron 17/exon 18 and one that introduced a stop codon that would truncate the last two amino acids of the encoded protein. Reviewing the recent reports on TTC7A mutations reveals correlation between the position and nature of the mutations with patient survival and clinical manifestations. Examination of public databases also suggests carrier status for healthy individuals, making a case for population screening on this gene, especially in populations with suspected frequent founder mutations.
    Matched MeSH terms: Introns
  9. Engku Fatimah Syairah Engku Safruddin, Wan Zainira Wan Zain, Bhavaraju, Venkata Murali Krishna, Kannan, Thirumulu Ponnuraj
    MyJurnal
    Given that the germline mutations of BRCA1 and BRCA2 confer genetic susceptibility to cancer, the
    genetic variations, polymorphisms or mutations are widely analyzed in Western countries. However, in Asian
    population, the prevalence of BRCA1 and BRCA2 polymorphisms is very limited. In Asia, breast cancer occurs in
    women early with an age of onset under 50 years. This review comprises the incidence of BRCA1 and BRCA2
    polymorphisms in the Japanese, Korean and Malaysian population. Founder mutations of BRCA1 and BRCA2
    were also compared to mark the genetic difference in these populations. The mutational analysis performed to
    analyze the entire coding region of BRCA1 and BRCA2 include the next generation sequencing and full
    sequencing of all exons and intron-exon junctions. From the diagnosis of triple negative breast cancer (TNBC)
    patients, TNBC is associated with the lack of tailored therapies and the treatment option available for TNBC
    patients is mainly chemotherapy. The poor prognosis of TNBC leads to determine the predictive biomarkers in
    order to develop treatment efficacy. This review will address the current clinical therapies available to treat TNBC
    patients.
    Matched MeSH terms: Introns
  10. Shullia NI, Raffiudin R, Juliandi B
    Trop Life Sci Res, 2019 Jan;30(1):89-107.
    PMID: 30847035 DOI: 10.21315/tlsr2019.30.1.6
    Genes related to carbohydrate metabolism have evolved rapidly in eusocial bees, including honey bees. However, the characterisation of carbohydrate metabolism genes has not been reported in Apis andreniformis or Apis cerana indica. This study aimed to characterise phosphofructokinase (PFK) and pyruvate kinase (PK) genes in these honey bee species and to analyse the evolution of the genus Apis using these genes. This study found the first data regarding A. andreniformis PFK and PK-like nucleotide sequences. A BLAST-n algorithm-based search showed that A. andreniformis and A. c. indica PFK and PK genes were homologous with those of Apis florea and Apis cerana cerana from Korea, respectively. Multiple alignments of PFKs from five Apis species showed many exon gains and losses, but only one among the PKs. Thus, the exon-intron organisation of the PK genes may be more conserved compare with that of the PFKs. Another evolutionary pattern indicated that more nucleotide substitutions occurred in Apis' PK than PFK genes. Deduced PFK amino acid sequences revealed a PFK consensus pattern of 19 amino acids, while the deduced PK amino acid sequences were predicted to have barrel and alpha/beta domains. Based on these two metabolism-related genes, The Neighbour-joining and Maximum likelihood phylogenetic trees are congruent and revealed that the A. andreniformis and A. florea group were in the basal position. Apis mellifera, A. cerana, and Apis dorsata formed a monophyletic clade, although the positions of A. mellifera and A. dorsata were different in the nucleotide- and amino acid-based phylogenetic trees.
    Matched MeSH terms: Introns
  11. Seethamchai S, Buppan P, Kuamsab N, Teeranaipong P, Putaporntip C, Jongwutiwes S
    Infect Genet Evol, 2018 11;65:35-42.
    PMID: 30016713 DOI: 10.1016/j.meegid.2018.07.015
    The amino acid substitution at residue 76 of the food vacuolar transmembrane protein encoded by the chloroquine resistance transporter gene of Plasmodium falciparum (Pfcrt) is an important, albeit imperfect, determinant of chloroquine susceptibility status of the parasite. Other mutations in Pfcrt can modulate susceptibility of P. falciparum to other antimalarials capable of interfering with heme detoxification process, and may exert compensatory effect on parasite growth rate. To address whether nationwide implementation of artemisinin combination therapy (ACT) in Thailand could affect sequence variation in exon 2 and introns of Pfcrt, we analyzed 136 P. falciparum isolates collected during 1997 and 2016 from endemic areas bordering Myanmar, Cambodia and Malaysia. Results revealed 6 haplotypes in exon 2 of Pfcrt with 2 novel substitutions at c.243A > G (p.R81) and c.251A > T (p.N84I). Positive selection was observed at amino acid residues 75, 76 and 97. Four, 3, and 2 alleles of microsatellite (AT/TA) repeats occurred in introns 1, 2 and 4, respectively, resulting in 7 different 3-locus haplotypes. The number of haplotypes and haplotype diversity of exon 2, and introns 1, 2 and 4 were significantly greater among isolates collected during 2009 and 2016 than those collected during 1997 and 2008 when 3-day ACT and 2-day ACT regimens were implemented nationwide, respectively (p 
    Matched MeSH terms: Introns*
  12. Zahari M, Sulaiman SA, Othman Z, Ayob Y, Karim FA, Jamal R
    Mediterr J Hematol Infect Dis, 2018;10(1):e2018056.
    PMID: 30210749 DOI: 10.4084/MJHID.2018.056
    Background: Haemophilia A (HA) and Haemophilia B (HB) are X-linked blood disorders that are caused by various mutations in the factor VIII (F8) and factor IX (F9) genes respectively. Identification of mutations is essential as some of the mutations are associated with the development of inhibitors. This study is the first comprehensive study of the F8 mutational profile in Malaysia.

    Materials and methods: We analysed 100 unrelated HA and 15 unrelated HB patients for genetic alterations in the F8 and F9 genes by using the long-range PCR, DNA sequencing, and the multiplex-ligation-dependent probe amplification assays. The prediction software was used to confirm the effects of these mutations on factor VIII and IX proteins.

    Results: 44 (53%) of the severe HA patients were positive for F8 intron 22 inversion, and three (3.6%) were positive for intron one inversion. There were 22 novel mutations in F8, including missense (8), frameshift (9), splice site (3), large deletion (1) and nonsense (1) mutations. In HB patients, four novel mutations were identified including the splice site (1), small deletion (1), large deletion (1) and missense (1) mutation.

    Discussion: The mutational spectrum of F8 in Malaysian patients is heterogeneous, with a slightly higher frequency of intron 22 inversion in these severe HA patients when compared to other Asian populations. Identification of these mutational profiles in F8 and F9 genes among Malaysian patients will provide a useful reference for the early detection and diagnosis of HA and HB in the Malaysian population.

    Matched MeSH terms: Introns
  13. Ghazali N, Rahman NA, Kannan TP, Jaafar S
    Cleft Palate Craniofac J, 2015 07;52(4):e88-94.
    PMID: 26151095 DOI: 10.1597/14-024
    OBJECTIVE: To determine the prevalence of mutations in transforming growth factor beta 3 (TGFβ3) and Jagged2 genes and their association with nonsyndromic cleft lip with or without cleft palate (CL±P) patients.

    DESIGN: Cross-sectional study on nonsyndromic CL±P and noncleft patients.

    SETTING: Reconstructive clinic and outpatient dental clinic, Hospital Universiti Sains Malaysia.

    PATIENTS: Blood samples of 96 nonsyndromic CL±P and 96 noncleft subjects.

    MAIN OUTCOME MEASURE: Prevalence and association of mutations in TGFβ3 and Jagged2 genes with nonsyndromic CL±P.

    RESULTS: Most of the nonsyndromic CL±P patients (53.1%) had left unilateral CLP. There were slightly more females (56.6%) compared with males. The prevalence of the mutations in the TGFβ3 gene was 17.7% (95% confidence interval [CI]: 9.5, 24.5) and in the Jagged2 gene was 12.5% (95% CI: 5.5, 18.5), which was higher compared with the noncleft group. For the TGFβ3 gene, there was no mutation in the coding region in either of the groups. All variants were single nucleotide polymorphisms located within the intronic flanking region. Two variants were identified (g.15812T>G and g.15966A>G) in both nonsyndromic CL±P and noncleft patients. However, the association was not significant (P > .05). Three variants (g.19779C>T, g.19547G>A, and g.19712C>T) were identified in the Jagged2 gene among nonsyndromic CL±P and noncleft patients. Only g.19712C>T showed a significant association with nonsyndromic CL±P patients (P = .039).

    CONCLUSION: g.19712C>T might play a crucial role in the development of cleft lip and palate. To the best of our knowledge, this is the first report of the mutation found within intron 13 of the Jagged2 gene among nonsyndromic CL±P Malay patients.

    Study site:Reconstructive and outpatient dental clinic, Hospital Universiti Sains Malaysia (HUSM)
    Matched MeSH terms: Introns
  14. Jo T, Momita S, Sadamori N, Tomonaga M, Fucharoem S, Fukumaki Y, et al.
    Intern. Med., 1992 Feb;31(2):269-72.
    PMID: 1600278
    A 26-year-old Chinese-Malaysian female patient with beta-thalassemia is presented. The main hematological values found in this patient were as follows: 1) normocytic hypochromic anemia (RBC 444 x 10(4)/microliters, Hb 11.8 g/dl) with marked anisopoikilocytosis, 2) erythroid hyperplasia, and 3) increased HbF (HbA 41.4%, HbA2 2.9%, HbF 48.9%). DNA obtained from peripheral leukocytes was analyzed using dot blot hybridization of the polymerase chain reaction (PCR)-amplified DNA with allele-specific oligonucleotide probes. A C----T substitution at position 654 of the second intervening sequence (IVS-2) was detected in her beta-globin clone.
    Matched MeSH terms: Introns
  15. Sng JH, Ali AB, Lee SC, Zahar D, Wong JE, Blake V, et al.
    J Med Genet, 2003 Oct;40(10):e117.
    PMID: 14569140
    Matched MeSH terms: Introns
  16. Karim KMR, Husaini A, Sing NN, Sinang FM, Roslan HA, Hussain H
    3 Biotech, 2018 Apr;8(4):204.
    PMID: 29607285 DOI: 10.1007/s13205-018-1225-z
    In this study, an alpha-amylase enzyme from a locally isolated Aspergillus flavus NSH9 was purified and characterized. The extracellular α-amylase was purified by ammonium sulfate precipitation and anion-exchange chromatography at a final yield of 2.55-fold and recovery of 11.73%. The molecular mass of the purified α-amylase was estimated to be 54 kDa using SDS-PAGE and the enzyme exhibited optimal catalytic activity at pH 5.0 and temperature of 50 °C. The enzyme was also thermally stable at 50 °C, with 87% residual activity after 60 min. As a metalloenzymes containing calcium, the purified α-amylase showed significantly increased enzyme activity in the presence of Ca2+ ions. Further gene isolation and characterization shows that the α-amylase gene of A. flavus NSH9 contained eight introns and an open reading frame that encodes for 499 amino acids with the first 21 amino acids presumed to be a signal peptide. Analysis of the deduced peptide sequence showed the presence of three conserved catalytic residues of α-amylase, two Ca2+-binding sites, seven conserved peptide sequences, and several other properties that indicates the protein belongs to glycosyl hydrolase family 13 capable of acting on α-1,4-bonds only. Based on sequence similarity, the deduced peptide sequence of A. flavus NSH9 α-amylase was also found to carry two potential surface/secondary-binding site (SBS) residues (Trp 237 and Tyr 409) that might be playing crucial roles in both the enzyme activity and also the binding of starch granules.
    Matched MeSH terms: Introns
  17. Gan HM, Thomas BN, Cavanaugh NT, Morales GH, Mayers AN, Savka MA, et al.
    PeerJ, 2017;5:e4030.
    PMID: 29158974 DOI: 10.7717/peerj.4030
    In industry, the yeast Rhodotorula mucilaginosa is commonly used for the production of carotenoids. The production of carotenoids is important because they are used as natural colorants in food and some carotenoids are precursors of retinol (vitamin A). However, the identification and molecular characterization of the carotenoid pathway/s in species belonging to the genus Rhodotorula is scarce due to the lack of genomic information thus potentially impeding effective metabolic engineering of these yeast strains for improved carotenoid production. In this study, we report the isolation, identification, characterization and the whole nuclear genome and mitogenome sequence of the endophyte R. mucilaginosa RIT389 isolated from Distemonanthus benthamianus, a plant known for its anti-fungal and antibacterial properties and commonly used as chewing sticks. The assembled genome of R. mucilaginosa RIT389 is 19 Mbp in length with an estimated genomic heterozygosity of 9.29%. Whole genome phylogeny supports the species designation of strain RIT389 within the genus in addition to supporting the monophyly of the currently sequenced Rhodotorula species. Further, we report for the first time, the recovery of the complete mitochondrial genome of R. mucilaginosa using the genome skimming approach. The assembled mitogenome is at least 7,000 bases larger than that of Rhodotorula taiwanensis which is largely attributed to the presence of large intronic regions containing open reading frames coding for homing endonuclease from the LAGLIDADG and GIY-YIG families. Furthermore, genomic regions containing the key genes for carotenoid production were identified in R. mucilaginosa RIT389, revealing differences in gene synteny that may play a role in the regulation of the biotechnologically important carotenoid synthesis pathways in yeasts.
    Matched MeSH terms: Introns
  18. Danderson CA, Downie SR, Hermann M
    Mol Phylogenet Evol, 2018 01;118:286-305.
    PMID: 29017853 DOI: 10.1016/j.ympev.2017.10.006
    The Arracacia clade (Apiaceae, Apioideae) is a heterogeneous assemblage of 12 genera, comprising 111 known species distributed in high montane temperate and sub-alpine habitats of meso- and South America. Previous studies have indicated that the genera Arracacia, Coulterophytum, and Prionosciadium are polyphyletic, but for the most part relationships among the members of the clade are largely unknown. Initially, cladistic analyses of nrDNA ITS sequences were carried out on 212 accessions (122 taxa), representing 92 species of the Arracacia clade and outgroups from the closely-related páramo genera Cotopaxia, Niphogeton, and Perissocoeleum and members of the Perennial Endemic North American clade and its allies. Using the ITS results to inform sampling of a small subset of taxa, a pilot study examining the phylogenetic utility of 20 noncoding chloroplast loci was subsequently performed to identify those regions most useful at resolving relationships. A cost-benefit analysis determined that five loci (trnQ-5'rps16, trnD-trnT, rpl32-trnL, psbD-trnT, ndhA intron) would maximize resolution and branch support in the clade. Cladistic analyses of four of these loci (trnQ-5'rps16, trnD-trnT, rpl32-trnL, ndhA intron) and the ITS region, separately and combined, revealed that Arracacia, Coaxana, Coulterophytum, Prionosciadium, and Rhodosciadium are each polyphyletic and that Donnellsmithia and Myrrhidendron are each monophyletic. Although most relationships in the Arracacia clade and among the closely-related genera Cotopaxia, Niphogeton, and Perissocoeleum are poorly resolved and supported, ten groups are recognized for future revisionary studies. Polyploidy and rapid species radiation have likely confounded generic circumscriptions and interpretation of relationships.
    Matched MeSH terms: Introns
  19. Avin FA, Subha B, Tan YS, Braukmann TWA, Vikineswary S, Hebert PDN
    Ecol Evol, 2017 09;7(17):6972-6980.
    PMID: 28904776 DOI: 10.1002/ece3.3049
    DNA barcoding involves the use of one or more short, standardized DNA fragments for the rapid identification of species. A 648-bp segment near the 5' terminus of the mitochondrial cytochrome c oxidase subunit I (COI) gene has been adopted as the universal DNA barcode for members of the animal kingdom, but its utility in mushrooms is complicated by the frequent occurrence of large introns. As a consequence, ITS has been adopted as the standard DNA barcode marker for mushrooms despite several shortcomings. This study employed newly designed primers coupled with cDNA analysis to examine COI sequence diversity in six species of Pleurotus and compared these results with those for ITS. The ability of the COI gene to discriminate six species of Pleurotus, the commonly cultivated oyster mushroom, was examined by analysis of cDNA. The amplification success, sequence variation within and among species, and the ability to design effective primers was tested. We compared ITS sequences to their COI cDNA counterparts for all isolates. ITS discriminated between all six species, but some sequence results were uninterpretable, because of length variation among ITS copies. By comparison, a complete COI sequences were recovered from all but three individuals of Pleurotus giganteus where only the 5' region was obtained. The COI sequences permitted the resolution of all species when partial data was excluded for P. giganteus. Our results suggest that COI can be a useful barcode marker for mushrooms when cDNA analysis is adopted, permitting identifications in cases where ITS cannot be recovered or where it offers higher resolution when fresh tissue is. The suitability of this approach remains to be confirmed for other mushrooms.
    Matched MeSH terms: Introns
  20. George E
    PMID: 8629111
    Beta-thalassemia in West Malaysia is caused by 14 molecular defects with differing clinical severity. In Chinese patients from West Malaysia, the main beta-thalassemia mutations seen were (a) a 4 base pair-TCTT deletion in codon 41-42 [frameshift mutation (FSC 41-42)]; (b) a C to T substitution at the second intervening sequence (IVS2-654); (c) an A to G substitution in the TATA box [-28 (A to G)], and (d) an A to T substitution in codon 17[17 A to T]. In the Malays, the main mutations seen were (a) a G to C in nucleotide 5 at the intervening sequence I [IVS1-5 (G to C)]; (b) G to T substitution in nucleotide I at the intervening sequence I [IVS1-1 (G to T)]; (c) a A to T substitution in codon 17 (17 A to T); (d) removal of C from codon 35 [codon 35 (-C)], and (e) a 4 base pairs-TCTT deletion in codon 41-42 [frameshift mutation (FSC 41-42)]. A scoring system (Tha1 CS) has been formulated to predict clinical severity. It is the type of beta-thalassemia mutation present that decides on the clinical phenotype. The most severe beta-thalassemia mutation is assigned a score of 4. A score of 8 indicates severe thalassemia.
    Matched MeSH terms: Introns
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