• Use of restriction endonucleases to analyze and generate a physical map of genomes, genes , or other segments of DNA . (lookformedical.com)
  • The sequence-specific DNA cleavage activity of restriction endonucleases (REases), combined with other enzymatic activities that amplify and ligate nucleic acids, have enabled modern molecular biology. (neb.com)
  • Furthermore, the discovery and engineering of nicking endonucleases (NEases) has opened the door to techniques such as isothermal amplification of DNA among others. (neb.com)
  • Any DNA from another species which gains entry into a living cell and lacks the characteristic methylation pattern will be recognized by the restriction endonucleases of similar specificity and destroyed by cleavage. (ouhsc.edu)
  • Daniel Nathans and Hamilton Smith received the 1978 Nobel Prize in physiology or medicine for their isolation of restriction endonucleases , which are able to cut DNA at specific sites. (fact-archive.com)
  • The platform accommodates parallel nicking on multiple "orthogonal" genomic DNA fragments, paired nicking and disassociation for creating "toehold" regions that enable single-bit random access and strand displacement. (biorxiv.org)
  • In contrast, this preferential DNA adduct formation at codons 12 and 14 was not observed in PCR-amplified DNA fragments containing the K-ras gene exon 1 sequence. (nih.gov)
  • During the acquisition phase, foreign DNA fragments are incorporated into CRISPR loci located in the bacterial and archeal genome. (ciccialab.com)
  • This was done by a large number of techniques that make use of DNA fragments (restriction fragment-length polymorphisms) so as to permit linkage mapping and gene sequencing. (medscape.com)
  • Together with ligase , which can join together fragments of DNA, restriction enzymes formed the initial basis of recombinant DNA technology. (fact-archive.com)
  • Because these technologies digitally tabulate the sequence of many individual DNA fragments, unlike conventional techniques which simply report the average genotype of an aggregate collection of molecules, they offer the unique ability to detect minor variants within heterogeneous mixtures [2]. (justia.com)
  • It contains fully referenced information about recognition and cleavage sites for both restriction enzymes and methyltransferases as well as commercial availability, methylation sensitivity, crystal and sequence data. (nih.gov)
  • All genomes that are completely sequenced are analyzed for RM system components, and with the advent of PacBio sequencing, the recognition sequences of DNA methyltransferases (MTases) are appearing rapidly. (nih.gov)
  • In molecular biology, REBASE is a database of information about restriction enzymes and DNA methyltransferases. (wikipedia.org)
  • The discrepancy between the conventional and in silico-predicted patterns is caused by impaired restriction digestion at specific Bst EII sites. (cdc.gov)
  • Types II and IV are composed of a methyltransferase, which, by modifying specific DNA sequence, protects 'self' DNA from cleavage, and an endonuclease allowing digestion of nonprotected DNA. (medscape.com)
  • To overcome these limitations, we developed DTECT (Dinucleotide signaTurE CapTure), a rapid and versatile detection method that relies on the capture of targeted dinucleotide signatures resulting from the digestion of genomic DNA amplicons by the type IIS restriction enzyme AcuI ( Billon et al, Cell Reports, 2020 , Figure 10). (ciccialab.com)
  • The assay facilitates selective digestion of host DNA by targeting enzyme restriction sites present in vertebrates but absent in parasites. (cdc.gov)
  • Evaluation of transcriptional efficiency of hepatitis team fortress hacks aimbot virus covalently closed circular DNA by reverse transcription-PCR combined with the restriction enzyme digestion method. (apcnet.org)
  • New England Biolabs offers a restriction endonuclease for virtually any DNA digestion. (qsneoscience.com)
  • RRBS is a powerful approach to genome-wide DNA methylation analysis that combines restriction enzyme digestion with bisulfite sequencing to enrich a CpG-dense fraction of the genome. (cd-genomics.com)
  • By combining enzyme digestion, bisulfite conversion and NGS technology, CD Genomics is able to provide RRBS as an alternative way to generate and profile genome-wide methylomes at a reduced cost. (cd-genomics.com)
  • Under conditions of extreme low-nitrogen stress in the model diazotroph Klebsiella oxytoca, we found remarkably high heterogeneity of nifHDK gene expression, which codes for the structural genes of nitrogenase, one key enzyme of the global nitrogen cycle. (imperial.ac.uk)
  • Significant GrSRs were observed with the presences of host genes in promoting the infection cycle at stages of adsorption, establishment, and viral release, but nonsignificant with the presence of immune systems, such as restriction-modification systems and CRISPR-Cas systems. (biomedcentral.com)
  • Soon after, the discovery and purification of REases that recognized and cut at specific sites (Type II REases) allowed scientists to perform precise manipulations of DNA in vitro , such as the cloning of exogenous genes and creation of efficient cloning vectors. (neb.com)
  • They will learn routine methods such as DNA cloning, isolation of DNA and restriction enzyme analysis, expression and purification of recombinant proteins, generation of plasmid constructs for targeted deletion of genes in bacteria, PCR and quantitative PCR, immunoblot analysis, in vitro and in vivo phenotypic analysis of bacterial strains. (utsa.edu)
  • By the mid 1980s, techniques largely had switched from those of the biochemistry of intermediates and enzymes to the identification of mutations in genes. (medscape.com)
  • Genetic engineering , genetic modification ( GM ), and gene splicing (once in widespread use but now deprecated) are terms for the process of manipulating genes in an organism, usually outside of the organism's normal reproductive process. (fact-archive.com)
  • The means by which 'genes' (in fact DNA strands that are assumed to have discrete effects) are detected and inserted are inexact, including such means as coating gold particles with DNA to be inserted and literally firing it at strands of target DNA (see gene gun ), which is guaranteed to cause insertions in at least some random locations, which can on rare occasion cause unplanned characteristics. (fact-archive.com)
  • DNA microarrays provide rapid screening for a large number of known genes. (blogspot.com)
  • Following release of rcDNA, this nucleic acid is 'repaired' to form stable covalently closed circular DNA (cccDNA), which serves as the template for transcription of viral genes and formation of the pregenomic RNA (pgRNA). (biomedcentral.com)
  • Genomic DNA modification might have affected the isolate's ribotyping profile. (cdc.gov)
  • Alteration of ribotyping patterns by genomic DNA modification of Corynebacterium ulcerans strains 0102, 0211, and FH2016-1, Japan, 2001-2016. (cdc.gov)
  • As a proof of concept, we used the multiple-turnover programmable restriction enzyme Pyrococcus furiosus Argonaute ( 13 ) to punch files into the PCR products of Escherichia coli genomic DNA. (biorxiv.org)
  • We have found that carcinogens preferentially form adducts at codons 12 and 14 in the K-ras gene exon 1 in intact as well as in fragmented genomic DNA. (nih.gov)
  • Detecting precise genomic modifications often requires sophisticated, expensive, and time-consuming experimental approaches. (ciccialab.com)
  • The advent of massively parallel DNA sequencing has ushered in a new era of genomic exploration by making simultaneous genotyping of hundreds of billions of base-pairs possible at small fraction of the time and cost of traditional Sanger methods [1]. (justia.com)
  • Founded in the mid-1970s as a collective of scientists committed to developing innovative products for the life sciences industry, New England Biolabs is now a recognized world leader in the discovery, development and commercialization of recombinant and native enzymes for genomic research.Created "by scientists for scientists", NEB is renowned for consistently providing exceptional product quality and unsurpassed technical support. (qsneoscience.com)
  • A supplier-of-choice for scientists across the globe, NEB offers the largest selection of recombinant and native enzymes for genomic research. (qsneoscience.com)
  • REBASE is a comprehensive and fully curated database of information about the components of restriction-modification (RM) systems. (nih.gov)
  • REBASE is one of the longest running biological databases having its roots in a collection of restriction enzymes maintained by Richard J. Roberts since before 1980. (wikipedia.org)
  • Cell array of character vectors containing the names of restriction enzymes from REBASE ® , the Restriction Enzyme Database. (mathworks.com)
  • REBASE, the Restriction Enzyme Database, is a collection of information about restriction enzymes and related proteins. (mathworks.com)
  • They catalyze the endonucleolytic cleavage of DNA sequences which lack the species-specific methylation pattern in the host cell's DNA . (lookformedical.com)
  • Hybridization can take place between two complimentary DNA sequences, between a single-stranded DNA and a complementary RNA, or between two RNA sequences. (lookformedical.com)
  • The first REases discovered recognized specific DNA sequences, but cut at variable distances away from their recognition sequence (Type I) and, thus were of little use in DNA manipulation. (neb.com)
  • This preferential carcinogen-DNA adduct formation at codons 12 and 14 could result from effects of (1) primary sequences of these codons and their surrounding codons in the K-ras gene, (2) the chromatin structure, and/or (3) epigenetic factors such as C5 cytosine methylation or other DNA modifications at these codons and their surrounding codons. (nih.gov)
  • 3 8 De novo methylation is thought to be initiated at embryogenesis by attraction of DNA methyl transferase to hairpin-like unimolecular fold backs of CGG repeat sequences expanded beyond a threshold of repeat length. (bmj.com)
  • There are different types of restriction enzymes which will cut the DNA at different base sequences. (bartleby.com)
  • The corresponding modification methylases are separate enzymes. (lookformedical.com)
  • DNA Modification Methylases" is a descriptor in the National Library of Medicine's controlled vocabulary thesaurus, MeSH (Medical Subject Headings) . (ouhsc.edu)
  • This graph shows the total number of publications written about "DNA Modification Methylases" by people in this website by year, and whether "DNA Modification Methylases" was a major or minor topic of these publications. (ouhsc.edu)
  • Below are the most recent publications written about "DNA Modification Methylases" by people in Profiles. (ouhsc.edu)
  • We also offer solutions for automation, site-directed mutagenesis, as well as your favorite restriction enzyme, ligase or competent cell products. (neb.com)
  • however, the RtcR CARF domain controls expression of two conserved RNA repair enzymes, cyclase RtcA and ligase RtcB. (imperial.ac.uk)
  • Optimize your cloning experiments with NEB's rigorously validated DNA modifying enzymes. (qsneoscience.com)
  • putative type I restriction enzymeP M protein [Ensembl]. (ntu.edu.sg)
  • Although direct identification of abnormal protein structure still was not possible, such defects could be inferred, indirectly, by demonstrating alterations in the kinetic properties of patients' enzymes (ie, rates of reaction as concentrations of cofactor or substrate were varied) or in the rate at which heating the enzyme altered its catalytic properties. (medscape.com)
  • Such changes allowed a strong inference of a change in the structure of the enzyme-protein. (medscape.com)
  • Sometimes, any one protein can undergo noticeable modifications under conditions of stress. (bioexplorer.net)
  • Analysis of protein and dprotein-DNA interactions. (bioexplorer.net)
  • Halogenated nucleotides are also photo-labile, and can be used in UV-crosslinking experiments to investigate the structure of protein-DNA complexes. (genelink.com)
  • It often involves the isolation, manipulation and reintroduction of DNA into model organisms , usually to express a protein . (fact-archive.com)
  • The aim is to introduce new characteristics to an organism to increase its usefulness such as, increasing the yield of a crop species, introducing a novel characteristic, or producing a new protein or enzyme. (fact-archive.com)
  • Since a protein is specified by a segment of DNA called a gene, future versions of that protein can be modified by changing the gene's underlying DNA. (fact-archive.com)
  • New England Biolabs sells a wide range of DNA, RNA and protein markers and ladders for your electrophoresis needs. (qsneoscience.com)
  • NEB offers several gene expression tools for DNA, RNA and protein transfection of many cell lines, including primary endothelial and epithelial cells. (qsneoscience.com)
  • [ 65 ] Type II restriction enzymes cut DNA at specific recognition motifs and are therefore widely used as molecular biology tools. (medscape.com)
  • They are closely related in their specificity and protect the DNA of a given bacterial species. (nih.gov)
  • His subsequent work included discovering the phenomenon of bacterial restriction and modification of phage DNA by means of enzymes, and elucidating the mechanisms by which certain proteins operate within bacterial cell membranes. (nih.gov)
  • In 1965, Werner Arber's seminal paper established the theoretical framework of the restriction-modification system, functioning as bacterial defense against invading bacteriophage (3). (neb.com)
  • This methylation is also at the heart of how restriction enzymes are produced in a bacterial cell that don't then chop up that own cell's DNA but are used to recognize foreign DNA. (genome.gov)
  • Thus, Type I and Type III systems can now be characterized in terms of recognition specificity merely by DNA sequencing. (nih.gov)
  • While this method showed a lot of potential in terms of specificity, selectivity and ease of use, the limit of detection presented (100 pM) was still far away from the concentrations of DNA found in liquid biopsies such as urine. (utwente.nl)
  • There are things like restriction enzymes, the CRISPR systems, and DNA modification systems. (nih.gov)
  • Since all commonly available pre-amplification techniques used for CRISPR sensing will result in a loss of epigenetic modifications we here present a methods to lower the limit of detection of this Cas12a assay, while keeping methylation selectivity. (utwente.nl)
  • Biologically active DNA which has been formed by the in vitro joining of segments of DNA from different sources. (lookformedical.com)
  • Previously, we have presented an amplification-free in vitro diagnostic tool to discriminate single CpG site methylation in DNA by the use of methylation-sensitive restriction enzymes (MSREs) followed by Cas12a-assisted sensing. (utwente.nl)
  • The result of this excision process is then further purified via a novel modification of a high throughput sequencing process on the Roche 454. (jcvi.org)
  • In practice, the combination of the restriction enzyme treatment with a subtly modified 454 sequencing approach is sufficient to provide an unbiased screen of the human epigenome," added Samuel Levy, the Director of Human Genomics at JCVI. (jcvi.org)
  • In the present study, a candidate gene associated with TGW was identified through specific-locus amplified fragment sequencing (SLAF-seq) of DNA bulks of recombinant inbred lines (RIL) derived from the cross between Jing 411 and Hongmangchun 21. (frontiersin.org)
  • Degraded DNA can complicate CpG methylome profiling using traditional techniques, particularly when performing methylation-sensitive restriction enzyme sequencing (MRE-seq), yielding high backgrounds and resulting in lowered library complexity. (wustl.edu)
  • The results using Capture MRE-seq correlate well (0.92) with traditional MRE-seq calls when profiling non-degraded samples, and can recover unmethylated regions in highly degraded samples when traditional MRE-seq fails, which we validate using bisulfite sequencing-based data (WGBS) as well as methylated DNA immunoprecipitation followed by sequencing (MeDIP-seq). (wustl.edu)
  • This modification makes amplicons immediately compatible with sequencing on the Illumina MiSeq platform, removing the need for a separate library preparation, which is expensive and time-consuming. (cdc.gov)
  • Currently, the two most popular methods of DNA sequencing are Sanger sequencing and next generation sequencing (NGS). (blogspot.com)
  • Next Generation DNA sequencing promises to revolutionize clinical medicine and basic research. (justia.com)
  • However, while this technology has the capacity to generate hundreds of billions of nucleotides of DNA sequence in a single experiment, the error rate of approximately 1% results in hundreds of millions of sequencing mistakes. (justia.com)
  • This approach greatly reduces errors by independently tagging and sequencing each of the two strands of a DNA duplex. (justia.com)
  • Although, in theory, DNA subpopulations of any size should be detectable when deep sequencing a sufficient number of molecules, a practical limit of detection is imposed by errors introduced during sample preparation and sequencing. (justia.com)
  • Profiling DNA methylome landscapes of mammalian cells with single-cell reduced-representation bisulfite sequencing. (cd-genomics.com)
  • Reduced representation bisulfite sequencing for comparative high-resolution DNA methylation analysis. (cd-genomics.com)
  • Analyze modifications to DNA and its associated proteins, histones and chromatin using New England Biolab's exceptional Epimark® reagents, enzymes, antibodies and DNA controls for Epigenetics research. (qsneoscience.com)
  • In this process, chemical tags called methyl groups attach to a particular location within DNA where they turn a gene on or off, thereby regulating the production of proteins that the gene encodes. (genome.gov)
  • Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. (lookformedical.com)
  • Gene transcription is carried out by RNA polymerase (RNAP) and requires the conversion of the initial closed promoter complex, where DNA is double stranded, to a transcription-competent open promoter complex, where DNA is opened up. (imperial.ac.uk)
  • TALENs are artificial restriction enzymes that can cut DNA upon contact, creating double-stranded breaks. (blogspot.com)
  • This method uniquely capitalizes on the redundant information stored in double-stranded DNA, thus overcoming technical limitations of prior methods utilizing data from only one of the two strands. (justia.com)
  • New England Biolabs is committed to providing a wide variety of essential reagents that serve to advance the frontier of DNA-based manipulations. (neb.com)
  • Persistence of the virus occurs as a result of stability of the replication intermediate comprising covalently closed circular DNA (cccDNA). (biomedcentral.com)
  • The epigenomic screen employs precise experimental manipulations using restriction enzymes that cut regulatory DNA in a defined manner. (jcvi.org)
  • The DNA Clean & Concentrator-5 is a PCR purification kit that provides purification of up to 5 µg DNA from PCR, endonuclease digestions, DNA modification reactions, isotope/fluorescence labeling reactions, etc. (zymoresearch.de)
  • Gene expression is regulated by histone modifications, which are post-translational modifications. (blogspot.com)
  • In concert with its co-repressor, KAP-1 (TRIM28), KRAB inhibits gene expression through recruitment of enzymes responsible for histone modification and methylation of CpG islands. (biomedcentral.com)
  • Unusual behaviour of SPO1 DNA with respect to restriction and modification enzymes recognizing the sequence 5'-G-G-C-C. Molecular and general genetics, Vol. 178, no. 1. (unibas.ch)
  • Enzyme systems containing a single subunit and requiring only magnesium for endonucleolytic activity. (lookformedical.com)
  • The observation of crosslinking only between the 5-Br-dU complementary to the first adenine in the restriction site demonstrated close contact between the major groove at this sequence and the S subunit (3). (genelink.com)
  • Our high quality reagents are available for every workflow, including popular DNA assembly methods such as NEBuilder ® HiFi DNA Assembly and NEBridge ® Golden Gate Assembly . (neb.com)
  • NEB offers a series of highly pure reagents for use in DNA and RNA sample preparation. (qsneoscience.com)
  • His research revolves around uncovering the stories and patterns held within DNA and RNA and is aimed at unraveling the evolutionary forces that shape biochemical functioning and biological form. (nih.gov)
  • Just like any other biological structure, DNA and RNA evolve over time, which can tell a complex story of an organism's past and illustrate relationships between organisms that aren't obvious. (nih.gov)
  • In this review, we will examine the major breakthroughs of REase research, applications of REases and NEases in various areas of biological research and novel technologies for assembling large DNA molecules. (neb.com)
  • A recent, but increasingly accepted idea among the international scientific community, is that the majority of cancers are caused by alterations, not only at the genetic level (i.e. mutations in the DNA sequence), but also at the epigenetic level, thus altering mechanisms that regulate gene expression. (jcvi.org)
  • This represents, however, a spread of genetic modification to medical purposes and opens an ethical door to other uses of the technology to directly modify human genomes. (fact-archive.com)
  • Such variations are generated by mutations that create or abolish recognition sites for these enzymes or change the length of the fragment. (lookformedical.com)
  • Through intensive research, scientists at NEB began engineering restriction enzymes that exhibit minimal, if any, star activity with extended reaction times and at high enzyme concentrations. (neb.com)
  • Column design allows DNA to be eluted at high concentrations into minimal volumes of water or TE buffer. (zymoresearch.de)
  • They are responsible for producing a species-characteristic methylation pattern, on either adenine or cytosine residues, in a specific short base sequence in the host cell's own DNA. (ouhsc.edu)
  • After more than half a century of research and development, the applications of REases have evolved from the cloning of exogenous DNA and genome mapping to more sophisticated applications, such as the identification and mapping of epigenetic modifications and the high-throughput assembly of combinatorial libraries. (neb.com)
  • The methylase adds methyl groups to adenine or cytosine residues in the same target sequence that constitutes the restriction enzyme binding site. (nih.gov)
  • Transferases are enzymes transferring a group, for example, the methyl group or a glycosyl group, from one compound (generally regarded as donor) to another compound (generally regarded as acceptor). (bvsalud.org)
  • DNA , which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine ), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine ). (lookformedical.com)
  • DNA is made up of a phosphate group, a sugar group and 4 nutrogen bases, which are adenine, hymine, guanine and cytosine. (bartleby.com)
  • Restriction-modification systems are important defenses against interspecies and even intraspecies uptake of exogenous and potentially harmful (e.g., bacteriophage) DNA. (medscape.com)
  • Once the plasmid has been removed from the bacteria, restriction enzymes will cut the plasmid at a specific region. (bartleby.com)
  • Some bacteria will methylate the sequence GAATTC and that's how they recognize their own DNA versus foreign invading DNA. (genome.gov)
  • The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells. (lookformedical.com)
  • It includes the recombination joint or edge of a heteroduplex region where two recombining DNA molecules are connected. (lookformedical.com)
  • Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. (lookformedical.com)
  • Methylation is a chemical modification of DNA and other molecules that may be retained as cells divide to make more cells. (genome.gov)
  • Defenders of the term genetic engineering argue that animal husbandry and crop breeding are also forms of genetic engineering that use artificial selection instead of modern genetic modification techniques. (fact-archive.com)
  • Cell array of character vectors or string vector representing the names of valid restriction enzymes. (mathworks.com)
  • Understanding the impact of DNA methylation within different disease contexts often requires accurate assessment of these modifications in a genome-wide fashion. (wustl.edu)
  • DNA methylation occurs predominantly in CpG contexts, and these CpG di-nucleotides are more abundant in selected regions of the genome. (cd-genomics.com)
  • The presence of restriction-modification systems limits the acquisition of foreign DNA in natural and laboratory conditions, and thus the possibility to construct mutants of S. aureus clinical isolates. (medscape.com)
  • 53BP1 limits the formation of recombinogenic single-strand DNA (ssDNA) in BRCA1-deficient cells, leading to defects in homologous recombination (HR). However, the exact mechanisms by which 53BP1 inhibits DSB resection remain unclear. (nih.gov)
  • Systems consisting of two enzymes, a modification methylase and a restriction endonuclease. (nih.gov)
  • Enzymes that are part of the restriction-modification systems. (lookformedical.com)
  • Synthetic DNA-based data storage systems ( 1 - 12 ) have received significant attention due to the promise of ultrahigh storage density. (biorxiv.org)
  • Variation occurring within a species in the presence or length of DNA fragment generated by a specific endonuclease at a specific site in the genome . (lookformedical.com)
  • In addition, cleavage of HBV DNA integrants within the host genome may result in chromosomal translocation. (biomedcentral.com)
  • RRBS utilizes the MspI restriction enzyme to cut at CCGG sites across the genome, enriching CpG-dense regions. (cd-genomics.com)
  • Briefly, the DNA is first digested, typically with MspI which is methylation insensitive and cuts at CCGG sites, enriching CpG rich regions of the genome. (cd-genomics.com)
  • Genetic modification or genetic manipulation are claimed to be neutral and possibly more technically correct terms for what is claimed, controversially, to be genetic engineering. (fact-archive.com)
  • Genetic engineering is when new DNA is added into an organism which does not already contain that type of DNA. (bartleby.com)
  • Find all possible enzymes that cut between bases 11 and 37. (mathworks.com)
  • To investigate an epigenetic approach to inactivating viral DNA, we engineered transcriptional repressors that comprise an HBV DNA-binding domain of transcription activator like effectors (TALEs) and a fused Krüppel Associated Box (KRAB). (biomedcentral.com)
  • Epigenetic modification of cccDNA with exogenous effectors is thus potentially a useful method to inhibit HBV replication without the risks associated with cleaving target DNA. (biomedcentral.com)
  • PacBio modification analysis revealed that 1 of these sites might have been modified ( Appendix Figure 1, panel B). Bst EII is sensitive to methylation and other types of DNA modification ( 14 ). (cdc.gov)
  • These results suggest that cytosine methylation at the CpG site is the major reason for the preferential DNA damage at codon 14 and that epigenetic modification(s) other than cytosine methylation may contribute to the preferential DNA damage at codon 12 of the K-ras gene. (nih.gov)
  • This genetic change can either be induced by a change in the DNA code (mutation) or epigenetic alterations, such as cytosine methylation. (utwente.nl)