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Apoptotic DNA Fragmentation
Apoptotic DNA fragmentation is a key feature of apoptosis, a type of programmed cell death. Apoptosis is characterized by the activation of endogenous endonucleases, particularly the caspase-3 activated DNase (CAD), with subsequent cleavage of nuclear DNA into internucleosomal fragments of roughly 180 base pairs (bp) and multiples thereof (360, 540 etc.). The apoptotic DNA fragmentation is being used as a marker of apoptosis and for identification of apoptotic cells either via the DNA laddering assay, the TUNEL assay, or the by detection of cells with fractional DNA content ("sub G1 cells") on DNA content frequency histograms e.g. as in the Nicoletti assay. Mechanism The enzyme responsible for apoptotic DNA fragmentation is the Caspase-Activated DNase (CAD). CAD is normally inhibited by another protein, the Inhibitor of Caspase Activated DNase (ICAD). During apoptosis, the apoptotic effector caspase, caspase-3, cleaves ICAD and thus causes CAD to become activated. CAD ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apoptotic DNA Laddering
Apoptosis (from grc, ἀπόπτωσις, apóptōsis, 'falling off') is a form of programmed cell death that occurs in multicellular organisms. Biochemical events lead to characteristic cell changes (morphology) and death. These changes include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, DNA fragmentation, and mRNA decay. The average adult human loses between 50 and 70 billion cells each day due to apoptosis. For an average human child between eight and fourteen years old, approximately twenty to thirty billion cells die per day. In contrast to necrosis, which is a form of traumatic cell death that results from acute cellular injury, apoptosis is a highly regulated and controlled process that confers advantages during an organism's life cycle. For example, the separation of fingers and toes in a developing human embryo occurs because cells between the digits undergo apoptosis. Unlike necrosis, apoptosis produces cell fragments called apoptotic bod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleosomes
A nucleosome is the basic structural unit of DNA packaging in eukaryotes. The structure of a nucleosome consists of a segment of DNA wound around eight histone proteins and resembles thread wrapped around a spool. The nucleosome is the fundamental subunit of chromatin. Each nucleosome is composed of a little less than two turns of DNA wrapped around a set of eight proteins called histones, which are known as a histone octamer. Each histone octamer is composed of two copies each of the histone proteins H2A, H2B, H3, and H4. DNA must be compacted into nucleosomes to fit within the cell nucleus. In addition to nucleosome wrapping, eukaryotic chromatin is further compacted by being folded into a series of more complex structures, eventually forming a chromosome. Each human cell contains about 30 million nucleosomes. Nucleosomes are thought to carry epigenetically inherited information in the form of covalent modifications of their core histones. Nucleosome positions in the geno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flow Cytometry
Flow cytometry (FC) is a technique used to detect and measure physical and chemical characteristics of a population of cells or particles. In this process, a sample containing cells or particles is suspended in a fluid and injected into the flow cytometer instrument. The sample is focused to ideally flow one cell at a time through a laser beam, where the light scattered is characteristic to the cells and their components. Cells are often labeled with fluorescent markers so light is absorbed and then emitted in a band of wavelengths. Tens of thousands of cells can be quickly examined and the data gathered are processed by a computer. Flow cytometry is routinely used in basic research, clinical practice, and clinical trials. Uses for flow cytometry include: * Cell counting * Cell sorting * Determining cell characteristics and function * Detecting microorganisms * Biomarker detection * Protein engineering detection * Diagnosis of health disorders such as blood cancers * Measuring ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TUNEL
Tunel or Tünel may refer to: * TUNEL assay (Terminal deoxynucleotidyl transferase mediated dUTP Nick End Labeling assay), in genetics, a method for detecting DNA fragmentation * Tunel (band), Yugoslav rock band * Tunel (railroad station), railroad station in Poland * Tünel, a historical underground funicular in Istanbul, Turkey * Tünel, Khövsgöl, a Mongolian sum * Tunel, a brand of Herbs de Majorca See also * * * Tunnel (other) A tunnel is an underground passage such as: Tunnel or Tunnels may also refer to: Film and TV * ''The Tunnel'' (1915 film), German silent, based on science fiction novel ''Der Tunnel'' by Bernhard Kellermann * ''The Tunnel'' (1933 German-langua ... * Tune (other) {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terminal Deoxynucleotidyl Transferase
Terminal deoxynucleotidyl transferase (TdT), also known as DNA nucleotidylexotransferase (DNTT) or terminal transferase, is a specialized DNA polymerase expressed in immature, pre-B, pre-T lymphoid cells, and acute lymphoblastic leukemia/lymphoma cells. TdT adds N-nucleotides to the V, D, and J exons of the TCR and BCR genes during antibody gene recombination, enabling the phenomenon of junctional diversity. In humans, terminal transferase is encoded by the ''DNTT'' gene. As a member of the X family of DNA polymerase enzymes, it works in conjunction with polymerase λ and polymerase μ, both of which belong to the same X family of polymerase enzymes. The diversity introduced by TdT has played an important role in the evolution of the vertebrate immune system, significantly increasing the variety of antigen receptors that a cell is equipped with to fight pathogens. Studies using TdT knockout mice have found drastic reductions (10-fold) in T-cell receptor (TCR) diversity compared w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Fragmentation
DNA fragmentation is the separation or breaking of DNA strands into pieces. It can be done intentionally by laboratory personnel or by cells, or can occur spontaneously. Spontaneous or accidental DNA fragmentation is fragmentation that gradually accumulates in a cell. It can be measured by e.g. the Comet assay or by the TUNEL assay. Men with sperm motility defects often have high levels of sperm DNA fragmentation. The degree of DNA fragmentation in sperm cells can predict outcomes for in vitro fertilization (IVF) and its expansion intracytoplasmic sperm injection (ICSI). The sperm chromatin dispersion test (SCD) and TUNEL assay are both effective in detecting sperm DNA damage. Using bright-field microscopy, the SCD test appears to be more sensitive than the TUNEL assay. Its main units of measurement is the DNA Fragmentation Index (DFI). A DFI of 20% or more significantly reduces the success rates after ICSI. DNA fragmentation was first documented by Williamson in 1970 when he obs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FEBS Letters
''FEBS Letters'' is a not-for-profit peer-reviewed scientific journal published on behalf of the Federation of European Biochemical Societies (FEBS) by Wiley. It covers all aspects of molecular biosciences, including molecular biology and biochemistry. The aim of the journal is to publish primary research in the form of Research Articles, Research Letters, Communications and Hypotheses, as well as secondary research in the form of Review articles. The journal also publishes a News and Views column calle"The Scientists' Forum" The editorial office of ''FEBS Letters'' is based in Heidelberg, Germany. The journal income is reinvested in science. History The initial idea of ''FEBS Letters'' as a journal for rapid communication of short reports in biochemistry, biophysics and molecular biology was proposed by the Secretary General of FEBS, W.J. Whelan, at the 4th FEBS Meeting held in Oslo in 1967. After further discussions and preparations, the first issue of ''FEBS Letters'' appeare ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biochemical And Biophysical Research Communications
''Biochemical and Biophysical Research Communications'' is a weekly peer-reviewed scientific journal covering all aspects of biochemistry and biophysics. It was established in 1959 by Academic Press and is currently published by Elsevier. The editor-in-chief is Wolfgang Baumeister (Max Planck Institute of Biochemistry). According to the ''Journal Citation Reports'', the journal has a 2020 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as ... of 3.575. Abstracting and indexing The journal is abstracted and indexed in: References External links * {{biophysics-journal-stub Elsevier academic journals Publications established in 1959 Biochemistry journals Biophysics journals English-language journals Weekly journals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Journal Of Cancer
The ''British Journal of Cancer'' is a twice-monthly professional medical journal owned by Cancer Research UK (a registered charity in the United Kingdom), published on their behalf by Springer Nature's Nature Research. The ''British Journal of Cancer'' (BJC) provides a forum for clinicians and scientists to communicate original research findings that have relevance to understanding the etiology of cancer and to improving patient treatment and survival. Once accepted, papers are published in print and online. Full research papers Academic publishing is the subfield of publishing which distributes academic research and scholarship. Most academic work is published in academic journal articles, books or theses. The part of academic written output that is not formally publ ... are published under six broad headings: * Clinical studies * Translational medicine, Translational therapeutics * Molecular diagnostics * Genetics and genomics * Cell biology, Cellular and molecular bio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andrew Wyllie (pathologist)
Andrew David Hamilton Wyllie FMedSci FRS (1944 – 26 May 2022) was a Scottish pathologist. In 1972, while working with electron microscopes at the University of Aberdeen he realised the significance of natural cell death. He and his colleagues John Kerr and Alastair Currie called this process apoptosis, from the use of this word in an ancient Greek poem to mean "falling off" (like leaves falling from a tree). He completed postdoctoral training in Cambridge University and became Professor of Experimental Pathology at the University of Edinburgh Medical School in 1992. He left Edinburgh for a chair at Cambridge in 1998 where he continued to lecture to undergraduate medical and natural sciences students. His works have contributed to the understanding of apoptosis in health and in disease. Apoptosis is used during early development to eliminate unwanted cells; for example, those between the fingers of a developing hand. In adults, apoptosis is used to rid the body of cells that ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Journal Of Molecular Biology
The ''Journal of Molecular Biology'' is a biweekly peer-reviewed scientific journal covering all aspects of molecular biology. It was established in 1959 and is published by Elsevier. The editor-in-chief is Peter Wright ( The Scripps Research Institute). Abstracting and indexing The journal is abstracted and indexed in: According to the ''Journal Citation Reports'', the journal has a 2020 impact factor of 5.469. Notable articles Some of the most highly cited articles that have appeared in the journal are: *, in which Jacques Monod, Jeffries Wyman, and Jean-Pierre Changeux presented the MWC model, that explained the cooperativity exhibited by allosteric proteins, such as hemoglobin. *, in which Edwin Southern presented the first description of nucleic acid blotting, a technique that revolutionized the field of molecular biology. *, in which the Smith–Waterman algorithm for determining the degree of homology of DNA, RNA, or protein sequences was first described. *, in which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
