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Epigenetics In Forensic Science
Epigenetics in forensic science is the application of epigenetics to solving crimes. Forensic science has been using DNA as evidence since 1984, however this does not give information about any changes in the individual since birth and will not be useful in distinguishing identical siblings. The focus of epigenetics in the forensic field is on non-heritable changes such as aging and diseases. Epigenetics involves any changes to the DNA that does not affect the sequence, but instead affects the activity of the DNA, such as the level of transcription of a particular gene. These changes can be passed down transgenerationally through the germline or arise after birth from environmental factors. In humans and other mammals, CpG dinucleotides are the main sequence that develops methylation, and because of this most studies on try and find unique methylation sites. There are a few methylation sites that have been determined as a cause of environmental influences from age, lifestyle, or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epigenetics
In biology, epigenetics is the study of changes in gene expression that happen without changes to the DNA sequence. The Greek prefix ''epi-'' (ἐπι- "over, outside of, around") in ''epigenetics'' implies features that are "on top of" or "in addition to" the traditional (DNA sequence based) genetic mechanism of inheritance. Epigenetics usually involves a change that is not erased by cell division, and affects the regulation of gene expression. Such effects on cellular and physiological traits may result from environmental factors, or be part of normal development. The term also refers to the mechanism of changes: functionally relevant alterations to the genome that do not involve mutation of the nucleotide sequence. Examples of mechanisms that produce such changes are DNA methylation and histone modification, each of which alters how genes are expressed without altering the underlying DNA sequence. Further, non-coding RNA sequences have been shown to play a key role in the r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forensic Science
Forensic science combines principles of law and science to investigate criminal activity. Through crime scene investigations and laboratory analysis, forensic scientists are able to link suspects to evidence. An example is determining the time and cause of death through autopsies. This evidence can then be used for proof towards a crime. Forensic science, often confused with criminalistics, is the application of science principles and methods to support legal decision-making in matters of Criminal law, criminal and Civil law (legal system), civil law. During criminal investigation in particular, it is governed by the legal standards of admissible evidence and criminal procedure. It is a broad field utilizing numerous practices such as the analysis of Genetic analysis, DNA, fingerprints, Bloodstain pattern analysis, bloodstain patterns, firearms, ballistics, toxicology, microscopy, and fire debris analysis. Forensic scientists collect, preserve, and analyze evidence during the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CpG Dinucleotide
The CpG sites or CG sites are regions of DNA where a cytosine nucleotide is followed by a guanine nucleotide in the linear sequence of bases along its 5' → 3' direction. CpG sites occur with high frequency in genomic regions called CpG islands. Cytosines in CpG dinucleotides can be methylated to form 5-methylcytosines. Enzymes that add a methyl group are called DNA methyltransferases. In mammals, 70% to 80% of CpG cytosines are methylated. Methylating the cytosine within a gene can change its expression, a mechanism that is part of a larger field of science studying gene regulation that is called epigenetics. Methylated cytosines often mutate to thymines. In humans, about 70% of promoters located near the transcription start site of a gene (proximal promoters) contain a CpG island. CpG characteristics Definition ''CpG'' is shorthand for ''5'—C—phosphate—G—3' '', that is, cytosine and guanine separated by only one phosphate group; phosphate links any two nucl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Methylation
DNA methylation is a biological process by which methyl groups are added to the DNA molecule. Methylation can change the activity of a DNA segment without changing the sequence. When located in a gene promoter (genetics), promoter, DNA methylation typically acts to repress gene Transcription (genetics), transcription. In mammals, DNA methylation is essential for normal development and is associated with a number of key processes including genomic imprinting, X-chromosome inactivation, repression of transposable elements, aging, and carcinogenesis. As of 2016, two nucleobases have been found on which natural, enzymatic DNA methylation takes place: adenine and cytosine. The modified bases are N6-methyladenine,D. B. Dunn, J. D. Smith: "The occurrence of 6-methylaminopurine in deoxyribonucleic acids". In: ''Biochem J.'' 68(4), Apr 1958, S. 627–636. [//www.ncbi.nlm.nih.gov/pubmed/13522672?dopt=Abstract PMID 13522672]. . 5-methylcytosineB. F. Vanyushin, S. G. Tkacheva, A. N. Belozers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryopreservation
Cryopreservation or cryoconservation is a process where biological material - cells, tissues, or organs - are frozen to preserve the material for an extended period of time. At low temperatures (typically or using liquid nitrogen) any cell metabolism which might cause damage to the biological material in question is effectively stopped. Cryopreservation is an effective way to transport biological samples over long distances, store samples for prolonged periods of time, and create a bank of samples for users. Molecules, referred to as cryoprotective agents (CPAs), are added to reduce the osmotic shock and physical stresses cells undergo in the freezing process. Some cryoprotective agents used in research are inspired by plants and animals in nature that have unique cold tolerance to survive harsh winters, including: trees, wood frogs, and tardigrades. The first human corpse to be frozen with the hope of future resurrection was James Bedford's, a few hours after his c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Assisted Reproductive Technology
Assisted reproductive technology (ART) includes medical procedures used primarily to address infertility. This subject involves procedures such as in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), and cryopreservation of gametes and embryos, and the use of fertility medication. When used to address infertility, ART may also be referred to as fertility treatment. ART mainly belongs to the field of reproductive endocrinology and infertility. Some forms of ART may be used with regard to fertile couples for genetic purpose (see preimplantation genetic diagnosis). ART may also be used in surrogacy arrangements, although not all surrogacy arrangements involve ART. The existence of sterility will not always require ART to be the first option to consider, as there are occasions when its cause is a mild disorder that can be solved with more conventional treatments or with behaviors based on promoting health and reproductive habits. Procedures General With ART, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epigenetic Clock
An epigenetic clock is a Biomarkers of aging, biochemical test that can be used to measure age. The test is based on modifications that change over time and regulate how genes are expressed. Typically, the test examines DNA methylation levels, measuring the accumulation of methyl groups to one's DNA molecules, or more recently, based on the histone code. History The strong effects of age on DNA methylation levels have been known since the late 1960s. A vast literature describes sets of CpG site, CpGs whose DNA methylation levels correlate with age. The first robust demonstration that DNA methylation levels in saliva could generate age predictors with an average accuracy of 5.2 years was published by a UCLA team including Sven Bocklandt, Steve Horvath, and Eric Vilain in 2011 (Bocklandt et al. 2011). The laboratories of Trey Ideker and Kang Zhang at the University of California, San Diego published the Hannum epigenetic clock (Hannum 2013), which consisted of 71 markers that accurate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KCNQ1DN
KCNQ1 downstream neighbour (KCNQ1DN) is a long non-coding RNA gene. In humans, it is located on chromosome 11p15.5 between the CDKN1C and KCNQ1 genes. It is an imprinted gene, expressed from the maternal allele. Reduced expression of KCNQ1DN is observed in Wilms' tumours. See also * Long noncoding RNA Long non-coding RNAs (long ncRNAs, lncRNA) are a type of RNA, generally defined as transcripts more than 200 nucleotides that are not translated into protein. This arbitrary limit distinguishes long ncRNAs from small non-coding RNAs, such as mic ... References Further reading * * * External links {{Rfam, id=RF01961, name=KCNQ1 downstream neighbour Non-coding RNA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NPTX2
Neuronal pentraxin-2 is a protein that in humans is encoded by the ''NPTX2'' gene. Function This gene encodes a member of the family of neuronal pentraxins, synaptic proteins that are related to C-reactive protein. This protein is involved in excitatory synapse formation. It also plays a role in clustering of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type glutamate receptors at established synapses, resulting in non-apoptotic cell death of dopaminergic nerve cells. Clinical significance Up-regulation of this gene in Parkinson disease Parkinson may refer to: *Parkinson (surname) * ''Parkinson'' (TV series), British chat show, presented by Sir Michael Parkinson *Parkinson, Queensland, suburb of Brisbane, Australia *The Parkinsons (fl. early 20th century), American father-and-son ... (PD) tissues suggests that the protein may be involved in the pathology of PD References Further reading * * * * * * * * * {{gene-7-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GRIA2
Glutamate ionotropic receptor AMPA type subunit 2 (also known as glutamate receptor 2 or GluR-2) is a protein in humans that is encoded by the ''GRIA2'' (also called ''GLUR2'') gene. It functions as a subunit of AMPA receptors. Function Glutamate receptors are the predominant excitatory neurotransmitter receptors in the mammalian brain and are activated in a variety of normal neurophysiologic processes. This gene product belongs to a family of glutamate receptors that are sensitive to alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA), called AMPA receptors, and function as ligand-activated cation channels. These channels are assembled from a combination of 4 subunits, encoded by 4 genes (''GRIA1-4''). The subunit encoded by this gene (''GRIA2'') is subject to RNA editing which renders the receptor that it becomes part of impermeable to calcium ions (Ca2+). Human and animal studies suggest that the RNA editing is essential for normal brain function, and defectiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elastic Net Regularization
In statistics and, in particular, in the fitting of linear or logistic regression models, the elastic net is a regularized regression method that linearly combines the ''L''1 and ''L''2 penalties of the lasso and ridge methods. Nevertheless, elastic net regularization is typically more accurate than both methods with regard to reconstruction. Specification The elastic net method overcomes the limitations of the LASSO (least absolute shrinkage and selection operator) method which uses a penalty function based on :\, \beta\, _1 = \textstyle \sum_^p , \beta_j, . Use of this penalty function has several limitations. For example, in the "large ''p'', small ''n''" case (high-dimensional data with few examples), the LASSO selects at most ''n'' variables before it saturates. Also if there is a group of highly correlated variables, then the LASSO tends to select one variable from a group and ignore the others. To overcome these limitations, the elastic net adds a quadratic part (\, \bet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNMT3B
DNA (cytosine-5)-methyltransferase 3 beta, is an enzyme that in humans in encoded by the DNMT3B gene. Mutation in this gene are associated with immunodeficiency, centromere instability and facial anomalies syndrome. Function CpG methylation is an epigenetic modification that is important for embryonic development, imprinting, and X-chromosome inactivation. Studies in mice have demonstrated that DNA methylation is required for mammalian development. This gene encodes a DNA methyltransferase which is thought to function in ''de novo'' methylation, rather than maintenance methylation. The protein localizes primarily to the nucleus and its expression is developmentally regulated. Eight alternatively spliced transcript variants have been described. The full length sequences of variants 4 and 5 have not been determined. Clinical significance Immunodeficiency-centromeric instability-facial anomalies (ICF) syndrome is a result of defects in lymphocyte maturation resulting from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
