Restriction Enzymes

2008 ◽  
pp. 17-27
Author(s):  
Gareth J. S. Jenkins
Keyword(s):  
Restriction Enzymes

Gene Frequency of CYP2D6*4 and *10 Variants in Karachi Population

2020 ◽  
Vol 17 ◽  
Author(s):  
Tamkeen Fatima ◽  
Farah Zeb ◽  
A. Dar Farooq
Keyword(s):  
Antipsychotic Drugs ◽  
Screening Program ◽  
Restriction Enzymes ◽  
Normal Subjects ◽  
Control Group ◽  
Poor Metabolizer ◽  
Cyp2d6 Polymorphism ◽  
Wild Allele ◽  
Schizophrenic Patients ◽  
Intermediate Metabolizer

Background: CYP2D6 is to be considered the most pronounced gene in pharmacegenetic field which is involved in metabolizing ~25% of all clinically used neuroleptic drugs and other antidepressants. We designed a study to evaluate differential expression of CYP2D6*4 and CYP2D6*10 variants which are very prevalent in Asian countries and exhibit variation in drug metabolizing ability that affect therapeutic responses. Objective: The purpose of this study is to determine the genotypic frequencies of CYP2D6 *1 (normal metabolizer), *4 (poor metabolizer) and *10 (intermediate metabolizer) variants among schizophrenic subjects and compared with control group from a sub-set of Karachi population. Method: Genomic deoxyribonucleic acid (DNA ) was extracted and amplified with CYP2D6*4 and *10 primers using polymerase chain reaction (PCR) and digested by Bacillus stereothermophilus (BstN1) and Hemophilus parahemolyticus (Hph1) restriction enzymes. The digested bands were identified as wild type or mutants and their genotypic frequencies were estimated statistically by Hardy-Weinberg equation (HWE) and analyzed further under non-parametric Chi-square test. Results: The results mentioned the frequencies of CYP2D6*1 wild allele (57%) which produces functional enzyme in normal subjects but CYP2D6*4 variant (9%) that produces non-functional enzyme and CYP2D6*10 allele (70%) produces altered enzyme with reduced activity that was most prevalent in schizophrenic patients. Conclusion : Genotyping of CYP2D6 alleles among schizophrenic patients indicated prevalence of *4 and *10 variants in Karachi population producing non-functional and reduced functional drugs metabolizing enzymes respectively that increases the incurability rate of schizophrenia. Therefore, CYP2D6 gene screening program should be conducted routinely in clinical practice to help clinicians to prescribing appropriate doses according to patient’s genotype and minimize the sufferings of schizophrenia. Discussion: In last, drug response is a complex phenomenon that is dependent on genetic and environmental factors. CYP2D6 polymorphism may un-cured the schizophrenia due to improper drug metabolism and protein-proteins interaction that may alter the antipsychotic drugs metabolism among patients with variable drug resposes. Gene testing system need to establish for analyzing maximum patient’s genotypes predicted with poor metabolizer, intermediate metabolizer and ultrarapid metabolizer for the adjustment of antipsychotic drugs.

scholarly journals Molecular variation in chloroplast DNA regions in ancestral species of wheat.

Genetics ◽  
1994 ◽  
Vol 137 (3) ◽  
pp. 883-889 ◽  
Author(s):  
N T Miyashita ◽  
N Mori ◽  
K Tsunewaki
Keyword(s):  
Chloroplast Dna ◽  
Restriction Enzymes ◽  
Triticum Dicoccoides ◽  
The Other ◽  
Major Type ◽  
Aegilops Speltoides ◽  
Triticum Timopheevi ◽  
Restriction Sites ◽  
D Values ◽  
Chloroplast Dna Regions

Abstract Restriction map variation in two 5-6-kb chloroplast DNA regions of five diploid Aegilops species in the section Sitopsis and two wild tetraploid wheats, Triticum dicoccoides and Triticum araraticum, was investigated with a battery of four-cutter restriction enzymes. A single accession each of Triticum durum, Triticum timopheevi and Triticum aestivum was included as a reference. More than 250 restriction sites were scored, of which only seven sites were found polymorphic in Aegilops speltoides. No restriction site polymorphisms were detected in all of the other diploid and tetraploid species. In addition, six insertion/deletion polymorphisms were detected, but they were mostly unique or species-specific. Estimated nucleotide diversity was 0.0006 for A. speltoides, and 0.0000 for all the other investigated species. In A. speltoides, none of Tajima's D values was significant, indicating no clear deviation from the neutrality of molecular polymorphisms. Significant non-random association was detected for three combinations out of 10 possible pairs between polymorphic restriction sites in A. speltoides. Phylogenetic relationship among all the plastotypes (plastid genotype) suggested the diphyletic origin of T. dicoccoides and T. araraticum. A plastotype of one A. speltoides accession was identical to the major type of T. araraticum (T. timopheevi inclusively). Three of the plastotypes found in the Sitopsis species are very similar, but not identical, to that of T. dicoccoides, T. durum and T. aestivum.

scholarly journals A cookbook for DNase Hi-C

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Maria Gridina ◽  
Evgeniy Mozheiko ◽  
Emil Valeev ◽  
Ludmila P. Nazarenko ◽  
Maria E. Lopatkina ◽  
...  
Keyword(s):  
Rational Design ◽  
Restriction Enzymes ◽  
Nucleotide Exchange ◽  
Computational Tools ◽  
3 Dimensional ◽  
Cultured Human Cells ◽  
Dna Ends ◽  
By Products ◽  
Robust Protocol

Abstract Background The Hi-C technique is widely employed to study the 3-dimensional chromatin architecture and to assemble genomes. The conventional in situ Hi-C protocol employs restriction enzymes to digest chromatin, which results in nonuniform genomic coverage. Using sequence-agnostic restriction enzymes, such as DNAse I, could help to overcome this limitation. Results In this study, we compare different DNAse Hi-C protocols and identify the critical steps that significantly affect the efficiency of the protocol. In particular, we show that the SDS quenching strategy strongly affects subsequent chromatin digestion. The presence of biotinylated oligonucleotide adapters may lead to ligase reaction by-products, which can be avoided by rational design of the adapter sequences. Moreover, the use of nucleotide-exchange enzymes for biotin fill-in enables simultaneous labelling and repair of DNA ends, similar to the conventional Hi-C protocol. These improvements simplify the protocol, making it less expensive and time-consuming. Conclusions We propose a new robust protocol for the preparation of DNAse Hi-C libraries from cultured human cells and blood samples supplemented with experimental controls and computational tools for the evaluation of library quality.

scholarly journals Lowering DNA binding affinity of SssI DNA methyltransferase does not enhance the specificity of targeted DNA methylation in E. coli

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Krystyna Ślaska-Kiss ◽  
Nikolett Zsibrita ◽  
Mihály Koncz ◽  
Pál Albert ◽  
Ákos Csábrádi ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Dna Binding ◽  
Binding Affinity ◽  
Dna Methyltransferase ◽  
Restriction Enzymes ◽  
Dna Binding Protein ◽  
E Coli ◽  
Dna Binding Affinity ◽  
Higher Eukaryotes

AbstractTargeted DNA methylation is a technique that aims to methylate cytosines in selected genomic loci. In the most widely used approach a CG-specific DNA methyltransferase (MTase) is fused to a sequence specific DNA binding protein, which binds in the vicinity of the targeted CG site(s). Although the technique has high potential for studying the role of DNA methylation in higher eukaryotes, its usefulness is hampered by insufficient methylation specificity. One of the approaches proposed to suppress methylation at unwanted sites is to use MTase variants with reduced DNA binding affinity. In this work we investigated how methylation specificity of chimeric MTases containing variants of the CG-specific prokaryotic MTase M.SssI fused to zinc finger or dCas9 targeting domains is influenced by mutations affecting catalytic activity and/or DNA binding affinity of the MTase domain. Specificity of targeted DNA methylation was assayed in E. coli harboring a plasmid with the target site. Digestions of the isolated plasmids with methylation sensitive restriction enzymes revealed that specificity of targeted DNA methylation was dependent on the activity but not on the DNA binding affinity of the MTase. These results have implications for the design of strategies of targeted DNA methylation.

Two type I restriction enzymes from Salmonella species

1985 ◽  
Vol 182 (4) ◽  
pp. 579-587 ◽  
Author(s):  
Valakunja Nagaraja ◽  
John C.W. Shepherd ◽  
Therese Pripfl ◽  
Thomas A. Bickle
Keyword(s):  
Restriction Enzymes ◽  
Type I

scholarly journals DNA Methylation in Solid Tumors: Functions and Methods of Detection

2021 ◽  
Vol 22 (8) ◽  
pp. 4247
Author(s):  
Andrea Martisova ◽  
Jitka Holcakova ◽  
Nasim Izadi ◽  
Ravery Sebuyoya ◽  
Roman Hrstka ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Solid Tumors ◽  
Epigenetic Modification ◽  
Single Gene ◽  
Restriction Enzymes ◽  
Methylation Analysis ◽  
Cpg Dinucleotides ◽  
Sequencing Technologies ◽  
Genome Level ◽  
Dna Methylation Analysis

DNA methylation, i.e., addition of methyl group to 5′-carbon of cytosine residues in CpG dinucleotides, is an important epigenetic modification regulating gene expression, and thus implied in many cellular processes. Deregulation of DNA methylation is strongly associated with onset of various diseases, including cancer. Here, we review how DNA methylation affects carcinogenesis process and give examples of solid tumors where aberrant DNA methylation is often present. We explain principles of methods developed for DNA methylation analysis at both single gene and whole genome level, based on (i) sodium bisulfite conversion, (ii) methylation-sensitive restriction enzymes, and (iii) interactions of 5-methylcytosine (5mC) with methyl-binding proteins or antibodies against 5mC. In addition to standard methods, we describe recent advances in next generation sequencing technologies applied to DNA methylation analysis, as well as in development of biosensors that represent their cheaper and faster alternatives. Most importantly, we highlight not only advantages, but also disadvantages and challenges of each method.

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