Displaying publications 1 - 20 of 92 in total

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  1. Mohd-Zin SW, Abdullah NL, Abdullah A, Greene ND, Cheah PS, Ling KH, et al.
    Genome, 2016 Jul;59(7):439-48.
    PMID: 27373307 DOI: 10.1139/gen-2015-0142
    The EphA4 receptor tyrosine kinase is involved in numerous cell-signalling activities during embryonic development. EphA4 has the ability to bind to both types of ephrin ligands, the ephrinAs and ephrinBs. The C57BL/6J-Epha4rb-2J/GrsrJ strain, denoted Epha4(rb-2J/rb-2J), is a spontaneous mouse mutant that arose at The Jackson Laboratory. These mutants exhibited a synchronous hind limb locomotion defect or "hopping gait" phenotype, which is also characteristic of EphA4 null mice. Genetic complementation experiments suggested that Epha4(rb-2J) corresponds to an allele of EphA4, but details of the genomic defect in this mouse mutant are currently unavailable. We found a single base-pair deletion in exon 9 resulting in a frame shift mutation that subsequently resulted in a premature stop codon. Analysis of the predicted structure of the truncated protein suggests that both the kinase and sterile α motif (SAM) domains are absent. Definitive determination of genotype is needed for experimental studies of mice carrying the Epha4(rb-2J) allele, and we have also developed a method to ease detection of the mutation through RFLP. Eph-ephrin family members are reportedly expressed as numerous isoforms. Hence, delineation of the specific mutation in EphA4 in this strain is important for further functional studies, such as protein-protein interactions, immunostaining and gene compensatory studies, investigating the mechanism underlying the effects of altered function of Eph family of receptor tyrosine kinases on phenotype.
    Matched MeSH terms: Codon, Terminator
  2. Rosli N, Sitam FT, Rovie-Ryan JJ, Gan HM, Lee YP, Hartini Ithnin, et al.
    Mitochondrial DNA B Resour, 2019 Jul 13;4(2):2535-2536.
    PMID: 33365614 DOI: 10.1080/23802359.2019.1640085
    Here, we present the first complete mitochondrial genome of Malayan Gaur (Bos gaurus hubbacki) inferred using next-generation sequencing. The mitogenome is 16,367 bp in length with the structural organization of a typical bovine mitochondrial arrangement comprising 13 protein-coding genes, 21 tRNAs, and 2 rRNAs. No internal stop codon was found in the protein-coding genes. Phylogenetic tree analysis revealed that Malayan gaur is more closely related to Burmese banteng instead of gaur.
    Matched MeSH terms: Codon, Terminator
  3. Hamzah A, Abdulrashid N
    J. Biochem. Mol. Biol. Biophys., 2002 Oct;6(5):365-9.
    PMID: 12385974
    The xylanase gene from Bacillus pumilus PJ19 amplified by polymerase chain reaction (PCR) was cloned into pCRII vector and transformed into Escherichia coli strain INValphaF'. Starting from an ATG as an initiator codon, an open reading frame coding for 202 amino acids was obtained. The recombinant xylanase sequence showed a 96% homology with the xylanase sequence from B. pumilus IPO strain and had an estimated molecular weight of 22,474. Xylanase activity expressed by E. coli INValphaF' harboring the cloned gene was located primarily in the cytoplasmic fraction.
    Matched MeSH terms: Codon/genetics
  4. Zangeneh FZ, Shoushtari MS, Shojaee S, Aboutorabi E
    Int J Reprod Biomed, 2020 Mar;18(3):165-174.
    PMID: 32309765 DOI: 10.18502/ijrm.v18i3.6712
    Background: Polycystic ovary syndrome (PCOS) is a multifactorial and heterogeneous disease that has a potent inheritable component based on familial clustering. Despite many studies in the genetic field of PCOS, the genes that are involved in the causes of this syndrome have not been thoroughly investigated.

    Objective: The purpose of this study was to establish the occurrence of the Trp64Arg polymorphism of beta3 adrenergic receptor in non-obese women with PCOS.

    Materials and Methods: This cross-sectional study was performed on 100 women with PCOS and normal women as the control group in Imam Khomeini Hospital of Tehran in 2016-2017. Peripheral blood sample (2 cc) was obtained from two groups for genomic DNA based on the gene bank. Polymorphisms were genotyped by of using ADRB3 Trp64Arg. Then the DNA was extracted by genomic kiagen kit. The primer was analyzed for PCR based on gene bank by using Primer3 software and then confirmed by primer Blast tool at NCBI site to conformity to the beta-3 adrenergic receptor gene. The protein changes were assessment by the Clastal W software.

    Results: The sequence analysis presented in NCBI, transcript variant 1, with the code NM_000025.2, shows changes in the amino acid sequence of exon 1 in women with PCOS. Polymorphism in the codon 64 encoding the amino acid tryptophan (W) occurred in the nucleotide c.T190C, which changed the nucleotide T to C and then the amino acid sequence of the tryptophan was altered to arginine pW64R.

    Conclusion: T-C polymorphism is evident in the codon 64 of the adrenergic β3 receptor in patients with PCOS. Therefore, Beta3 adrenergic receptor gene polymorphism (Thr164Ile) associates with this syndrome in nonobese women.

    Matched MeSH terms: Codon
  5. Mohd Khalid MK, Yakob Y, Md Yasin R, Wee Teik K, Siew CG, Rahmat J, et al.
    Mol Vis, 2015;21:1185-90.
    PMID: 26539030
    The availability of molecular genetic testing for retinoblastoma (RB) in Malaysia has enabled patients with a heritable predisposition to the disease to be identified, which thus improves the clinical management of these patients and their families. In this paper, we presented our strategy for performing molecular genetic testing of the RB1 gene and the findings from our first 2 years of starting this service.
    Matched MeSH terms: Codon, Nonsense
  6. Mualif SA, Teow SY, Omar TC, Chew YW, Yusoff NM, Ali SA
    PLoS One, 2015;10(7):e0130446.
    PMID: 26147991 DOI: 10.1371/journal.pone.0130446
    Relative ease in handling and manipulation of Escherichia coli strains make them primary candidate to express proteins heterologously. Overexpression of heterologous genes that contain codons infrequently used by E. coli is related with difficulties such as mRNA instability, early termination of transcription and/or translation, deletions and/or misincorporation, and cell growth inhibition. These codon bias -associated problems are addressed by co-expressing ColE1-compatible, rare tRNA expressing helper plasmids. However, this approach has inadequacies, which we have addressed by engineering an expression vector that concomitantly expresses the heterologous protein of interest, and rare tRNA genes in E. coli. The expression vector contains three (argU, ileY, leuW) rare tRNA genes and a useful multiple cloning site for easy in-frame cloning. To maintain the overall size of the parental plasmid vector, the rare tRNA genes replaced the non-essential DNA segments in the vector. The cloned gene is expressed under the control of T7 promoter and resulting recombinant protein has a C-terminal 6His tag for IMAC-mediated purification. We have evaluated the usefulness of this expression vector by expressing three HIV-1 genes namely HIV-1 p27 (nef), HIV-1 p24 (ca), and HIV-1 vif in NiCo21(DE3) E.coli and demonstrated the advantages of using expression vector that concomitantly expresses rare tRNA and heterologous genes.
    Matched MeSH terms: Codon/genetics
  7. Shmukler BE, Kedar PS, Warang P, Desai M, Madkaikar M, Ghosh K, et al.
    Am J Hematol, 2010 Oct;85(10):824-8.
    PMID: 20799361 DOI: 10.1002/ajh.21836
    Familial distal renal tubular acidosis (dRTA) can be caused by mutations in the Cl2/HCO32 exchanger of the renal Type A intercalated cell, kidney AE1/SLC4A1. dRTA-associated AE1 mutations have been reported in families from North America, Europe, Thailand, Malaysia, Papua-New Guinea, Taiwan, and the Philippines, but not India. The dRTA mutation AE1 A858D has been detected only in the context of compound heterozygosity. We report here two unrelated Indian patients with combined hemolytic anemia and dRTA who share homozygous A858D mutations of the AE1/SLC4A1 gene. The mutation creates a novel restriction site that is validated for diagnostic screening.
    Matched MeSH terms: Codon/genetics
  8. Mazumdar P, Binti Othman R, Mebus K, Ramakrishnan N, Ann Harikrishna J
    Ann Bot, 2017 Nov 28;120(6):893-909.
    PMID: 29155926 DOI: 10.1093/aob/mcx112
    Background and Aims: Studies on codon usage in monocots have focused on grasses, and observed patterns of this taxon were generalized to all monocot species. Here, non-grass monocot species were analysed to investigate the differences between grass and non-grass monocots.

    Methods: First, studies of codon usage in monocots were reviewed. The current information was then extended regarding codon usage, as well as codon-pair context bias, using four completely sequenced non-grass monocot genomes (Musa acuminata, Musa balbisiana, Phoenix dactylifera and Spirodela polyrhiza) for which comparable transcriptome datasets are available. Measurements were taken regarding relative synonymous codon usage, effective number of codons, derived optimal codon and GC content and then the relationships investigated to infer the underlying evolutionary forces.

    Key Results: The research identified optimal codons, rare codons and preferred codon-pair context in the non-grass monocot species studied. In contrast to the bimodal distribution of GC3 (GC content in third codon position) in grasses, non-grass monocots showed a unimodal distribution. Disproportionate use of G and C (and of A and T) in two- and four-codon amino acids detected in the analysis rules out the mutational bias hypothesis as an explanation of genomic variation in GC content. There was found to be a positive relationship between CAI (codon adaptation index; predicts the level of expression of a gene) and GC3. In addition, a strong correlation was observed between coding and genomic GC content and negative correlation of GC3 with gene length, indicating a strong impact of GC-biased gene conversion (gBGC) in shaping codon usage and nucleotide composition in non-grass monocots.

    Conclusion: Optimal codons in these non-grass monocots show a preference for G/C in the third codon position. These results support the concept that codon usage and nucleotide composition in non-grass monocots are mainly driven by gBGC.

    Matched MeSH terms: Codon/genetics*
  9. Tan MH, Gan HM, Lee YP, Austin CM
    Mitochondrial DNA A DNA Mapp Seq Anal, 2016 11;27(6):3981-3982.
    PMID: 25541307
    The mitochondrial genome sequence of the purple mottled shore crab, Cyclograpsus granulosus, is documented (GenBank accession number: LN624373), which makes it the third for genera of the superfamily Grapsoidea. Cyclograpsus granulosus has a mitogenome of 16,300 bp consisting of 13 protein-coding genes, two ribosomal subunit genes, 22 transfer RNAs and a non-coding AT-rich region. The base composition of the C. granulosus mitogenome is 36.15% for T, 19.54% for C, 33.14% for A and 11.17% for G, with an AT bias of 69.29%. The mitogenome gene order is atypical for the brachyuran crabs, but is identical to species of the genus Eriocheir from the same family.
    Matched MeSH terms: Codon, Initiator; Codon, Terminator
  10. Tan MH, Gan HM, Lee YP, Austin CM
    Mitochondrial DNA A DNA Mapp Seq Anal, 2016 11;27(6):3983-3984.
    PMID: 25541305
    The mitochondrial genome sequence of the porcellanid crab, Petrolisthes haswelli is provided, making it the second for the family Porcellanidae and the third for the superfamily Galatheoidea. Petrolisthes haswelli has a mitogenome of 15,348 bp consisting of 13 protein-coding genes, two ribosomal subunit genes, 22 transfer RNAs and a non-coding AT-rich region. The base composition of the P. haswelli mitogenome is 35.66% for T, 18.65% for C, 34.35% for A and 11.34% for G, with an AT bias of 70.01%. The mitogenome gene order is identical to the mitogenome of Neopetrolisthes maculatus, the only other species of the family with a sequenced mitogenome.
    Matched MeSH terms: Codon, Initiator; Codon, Terminator
  11. Grandjean F, Tan MH, Gan HY, Gan HM, Austin CM
    PMID: 25738217 DOI: 10.3109/19401736.2015.1018207
    The Austropotamobius pallipes complete mitogenome has been recovered using Next-Gen sequencing. Our sample of A. pallipes has a mitogenome of 15,679 base pairs (68.44% A + T content) made up of 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs, and a 877 bp non-coding AT-rich region. This is the first mitogenome sequenced for a crayfish from the family Astacidae and the 4(th) for northern hemisphere genera.
    Matched MeSH terms: Codon
  12. Lee YP, Gan HM, Tan MH, Lys I, Page R, Dias Wanigasekera B, et al.
    PMID: 25707411 DOI: 10.3109/19401736.2015.1018209
    The mitogenome of Paranephrops planifrons, was obtained by next generation sequencing. This crayfish has a mitochondrial genome of 16,174 base pairs with 13 protein-coding genes, 2 ribosomal subunit genes, 22 transfer RNAs (tRNA), and a non-coding AT-rich region of 771 bp. The P. planifrons nucleotide composition is: 33.63% for T, 21.92% for C, 34.46% for A, and 9.98% for G and has a 68.09% AT bias. While the mitogenome gene order for this species is consistent with aspects of the highly distinctive parastacid crayfish mitogenome gene arrangement, it has a novel gene order involving the rearrangements of a protein coding and several tRNA genes.
    Matched MeSH terms: Codon
  13. Gan HM, Gan HY, Tan MH, Penny SS, Willan RC, Austin CM
    PMID: 25648928 DOI: 10.3109/19401736.2015.1007355
    The complete mitochondrial genome of the commercially and ecologically important and internationally vulnerable giant clam Tridacna squamosa was recovered by genome skimming using the MiSeq platform. The T. squamosa mitogenome has 20,930 base pairs (62.35% A+T content) and is made up of 12 protein-coding genes, 2 ribosomal subunit genes, 24 transfer RNAs, and a 2594 bp non-coding AT-rich region. The mitogenome has a relatively large insertion in the atp6 gene. This is the first mitogenome to be sequenced from the genus Tridacna, and the family Tridacnidae and represents a new gene order.
    Matched MeSH terms: Codon
  14. Gan HM, Tan MH, Lee YP, Schultz MB, Horwitz P, Burnham Q, et al.
    Mol Phylogenet Evol, 2018 01;118:88-98.
    PMID: 28966124 DOI: 10.1016/j.ympev.2017.09.022
    To further understand the evolutionary history and mitogenomic features of Australia's highly distinctive freshwater crayfish fauna, we utilized a recently described rapid mitogenome sequencing pipeline to generate 24 new crayfish mitogenomes including a diversity of burrowing crayfish species and the first for Astacopsis gouldi, the world's largest freshwater invertebrate. Whole mitogenome-based phylogeny estimates using both Bayesian and Maximum Likelihood methods substantially strengthen existing hypotheses for systematic relationships among Australian freshwater crayfish with evidence of pervasive diversifying selection and accelerated mitochondrial substitution rate among the members of the clade representing strongly burrowing crayfish that may reflect selection pressures for increased energy requirement for adaptation to terrestrial environment and a burrowing lifestyle. Further, gene rearrangements are prevalent in the burrowing crayfish mitogenomes involving both tRNA and protein coding genes. In addition, duplicated control regions were observed in two closely related Engaeus species, together with evidence for concerted evolution. This study significantly adds to the understanding of Australian freshwater crayfish evolutionary relationships and suggests a link between mitogenome evolution and adaptation to terrestrial environments and a burrowing lifestyle in freshwater crayfish.
    Matched MeSH terms: Codon
  15. Ahmad M, Jung LT, Bhuiyan MA
    Comput Biol Med, 2016 Feb 1;69:144-51.
    PMID: 26773936 DOI: 10.1016/j.compbiomed.2015.12.017
    A coding measure scheme numerically translates the DNA sequence to a time domain signal for protein coding regions identification. A number of coding measure schemes based on numerology, geometry, fixed mapping, statistical characteristics and chemical attributes of nucleotides have been proposed in recent decades. Such coding measure schemes lack the biologically meaningful aspects of nucleotide data and hence do not significantly discriminate coding regions from non-coding regions. This paper presents a novel fuzzy semantic similarity measure (FSSM) coding scheme centering on FSSM codons׳ clustering and genetic code context of nucleotides. Certain natural characteristics of nucleotides i.e. appearance as a unique combination of triplets, preserving special structure and occurrence, and ability to own and share density distributions in codons have been exploited in FSSM. The nucleotides׳ fuzzy behaviors, semantic similarities and defuzzification based on the center of gravity of nucleotides revealed a strong correlation between nucleotides in codons. The proposed FSSM coding scheme attains a significant enhancement in coding regions identification i.e. 36-133% as compared to other existing coding measure schemes tested over more than 250 benchmarked and randomly taken DNA datasets of different organisms.
    Matched MeSH terms: Codon/genetics*
  16. Cruz L, György B, Cheah PS, Kleinstiver BP, Eimer WA, Garcia SP, et al.
    Mol Ther Nucleic Acids, 2020 Sep 04;21:1-12.
    PMID: 32502938 DOI: 10.1016/j.omtn.2020.05.009
    Most individuals affected with DYT1 dystonia have a heterozygous 3-bp deletion in the TOR1A gene (c.907_909delGAG). The mutation appears to act through a dominant-negative mechanism compromising normal torsinA function, and it is proposed that reducing mutant torsinA may normalize torsinA activity. In this study, we used an engineered Cas9 variant from Streptococcus pyogenes (SpCas9-VRQR) to target the mutation in the TOR1A gene in order to disrupt mutant torsinA in DYT1 patient fibroblasts. Selective targeting of the DYT1 allele was highly efficient with most common non-homologous end joining (NHEJ) edits, leading to a predicted premature stop codon with loss of the torsinA C terminus (delta 302-332 aa). Structural analysis predicted a functionally inactive status of this truncated torsinA due to the loss of residues associated with ATPase activity and binding to LULL1. Immunoblotting showed a reduction of the torsinA protein level in Cas9-edited DYT1 fibroblasts, and a functional assay using HSV infection indicated a phenotypic recovery toward that observed in control fibroblasts. These findings suggest that the selective disruption of the mutant TOR1A allele using CRISPR-Cas9 inactivates mutant torsinA, allowing the remaining wild-type torsinA to exert normal function.
    Matched MeSH terms: Codon, Nonsense
  17. Yong HS, Song SL, Chua KO, Wayan Suana I, Eamsobhana P, Tan J, et al.
    Sci Rep, 2021 May 21;11(1):10680.
    PMID: 34021208 DOI: 10.1038/s41598-021-90162-1
    Spiders of the genera Nephila and Trichonephila are large orb-weaving spiders. In view of the lack of study on the mitogenome of these genera, and the conflicting systematic status, we sequenced (by next generation sequencing) and annotated the complete mitogenomes of N. pilipes, T. antipodiana and T. vitiana (previously N. vitiana) to determine their features and phylogenetic relationship. Most of the tRNAs have aberrant clover-leaf secondary structure. Based on 13 protein-coding genes (PCGs) and 15 mitochondrial genes (13 PCGs and two rRNA genes), Nephila and Trichonephila form a clade distinctly separated from the other araneid subfamilies/genera. T. antipodiana forms a lineage with T. vitiana in the subclade containing also T. clavata, while N. pilipes forms a sister clade to Trichonephila. The taxon vitiana is therefore a member of the genus Trichonephila and not Nephila as currently recognized. Studies on the mitogenomes of other Nephila and Trichonephila species and related taxa are needed to provide a potentially more robust phylogeny and systematics.
    Matched MeSH terms: Codon
  18. Lee MHP, Tan CW, Tee HK, Ong KC, Sam IC, Chan YF
    Vaccine, 2021 03 19;39(12):1708-1720.
    PMID: 33640144 DOI: 10.1016/j.vaccine.2021.02.024
    Enterovirus A71 (EV-A71) causes hand, foot and mouth disease (HFMD) in young children. It is associated with severe neurological complications and death. This study aims to develop a live-attenuated vaccine by codon deoptimization (CD) and codon-pair deoptimization (CPD) of EV-A71. CD is generated by introducing the least preferred codons for amino acids while CPD increases the presence of underrepresented codon pairs in the specific genes. CD and CPD chimeras were generated by synonymous mutations at the VP2, VP3, VP1 and 2A gene regions, designated as XYZ. All twelve deoptimized viruses were viable with similar replication kinetics, but the plaque sizes were inversely proportional to the level of deoptimization. All the deoptimized viruses showed attenuated growth in vitro with reduced viral protein expression at 48 h and lower viral RNA at 39 °C. Six-week-old ICR mice were immunized intraperitoneally with selected CD and CPD X and XY vaccine candidates covering the VP2-VP3 and VP2-VP3-VP1 genes, respectively. All vaccine candidates elicited high anti-EV-A71 IgG levels similar to wild-type (WT) EV-A71. The CD X and CPD X vaccines produced robust neutralizing antibodies but not the CD XY and CPD XY. On lethal challenge, offspring of mice immunized with WT, CD X and CPD X were fully protected, but the CD XY- and CPD XY-vaccinated mice had delayed symptoms and eventually died. Similarly, active immunization of 1-day-old suckling mice with CD X, CPD X and CD XY vaccine candidates provided complete immune protection but CPD XY only protected 40% of the challenged mice. Histology of the muscles from CD X- and CPD X-vaccinated mice showed minimal pathology compared to extensive inflammation in the post-challenged mock-vaccinated mice. Overall, we demonstrated that the CD X and CPD X elicited good neutralizing antibodies, conferred immune protection and are promising live-attenuated vaccine candidates for EV-A71.
    Matched MeSH terms: Codon
  19. Lim KP, Sharifah H, Lau SH, Teo SH, Cheong SC
    Oncol Rep, 2005 Oct;14(4):963-8.
    PMID: 16142358 DOI: 10.3892/or.14.4.963
    The majority of global incidences of oral cancer occur in Asia, and the aetiology of oral cancer is different in Asia as it is in the West. However, whereas there is a growing understanding of the molecular mechanisms of oral cancer progression in the West, there is little progress in this understanding in Asia. In particular, the role of the p53 pathway in modulating cancer progression in Asian oral cancer remains unclear. In this study, we micro-dissected and analysed 20 well-differentiated oral squamous cell carcinoma specimens for alterations in the p53 pathway. We found that 6/20 samples contained mutations in the p53 gene which occurred in three hotspots, at codon 203, 218 and 296. Furthermore, 6/20 samples had a homozygous deletion of p14ARF, but notably p14ARF deletion and p53 mutation events were often independent and mutually exclusive. Strikingly, MDM2 was upregulated in 20/20 samples, but not in 3/3 normal tissue specimens. Taken together, these data suggest that inactivation of the p53 pathway is a frequent event in oral squamous cell carcinoma, which occurs by an aberration in one of a number of players in the p53 pathway.
    Matched MeSH terms: Codon
  20. Hussain H, Chong NF
    Biomed Res Int, 2016;2016:8041532.
    PMID: 27995143
    The combined overlap extension PCR (COE-PCR) method developed in this work combines the strengths of the overlap extension PCR (OE-PCR) method with the speed and ease of the asymmetrical overlap extension (AOE-PCR) method. This combined method allows up to 6 base pairs to be mutated at a time and requires a total of 40-45 PCR cycles. A total of eight mutagenesis experiments were successfully carried out, with each experiment mutating between two to six base pairs. Up to four adjacent codons were changed in a single experiment. This method is especially useful for codon optimization, where doublet or triplet rare codons can be changed using a single mutagenic primer set, in a single experiment.
    Matched MeSH terms: Codon/genetics*
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