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Polycomb-group
Polycomb-group proteins (PcG proteins) are a family of protein complexes first discovered in fruit flies that can remodel chromatin such that epigenetic silencing of genes takes place. Polycomb-group proteins are well known for silencing Hox genes through modulation of chromatin structure during embryonic development in fruit flies ('' Drosophila melanogaster''). They derive their name from the fact that the first sign of a decrease in PcG function is often a homeotic transformation of posterior legs towards anterior legs, which have a characteristic comb-like set of bristles. In insects In '' Drosophila'', the Trithorax-group (trxG) and Polycomb-group (PcG) proteins (They derive their name from the fact that the first sign of a decrease in PcG function is often a homeotic transformation of posterior legs towards anterior legs, which have a characteristic comb-like set of bristles) act antagonistically and interact with chromosomal elements, termed Cellular Memory Modules (CM ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polycomb Group Proteins And Cancer
Polycomb-group proteins (PcG proteins) are a family of protein complexes first discovered in fruit flies that can remodel chromatin such that epigenetic silencing of genes takes place. Polycomb-group proteins are well known for silencing Hox genes through modulation of chromatin structure during embryonic development in fruit flies (''Drosophila melanogaster''). They derive their name from the fact that the first sign of a decrease in PcG function is often a homeotic transformation of posterior legs towards anterior legs, which have a characteristic comb-like set of bristles. In insects In ''Drosophila'', the Trithorax-group (trxG) and Polycomb-group (PcG) proteins (They derive their name from the fact that the first sign of a decrease in PcG function is often a homeotic transformation of posterior legs towards anterior legs, which have a characteristic comb-like set of bristles) act antagonistically and interact with chromosomal elements, termed Cellular Memory Modules (CMMs). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BMI1
Polycomb complex protein BMI-1 also known as polycomb group RING finger protein 4 (PCGF4) or RING finger protein 51 (RNF51) is a protein that in humans is encoded by the ''BMI1'' gene ( B cell-specific Moloney murine leukemia virus integration site 1). BMI1 is a polycomb ring finger oncogene. Function BMI1 (B lymphoma Mo-MLV insertion region 1 homolog) has been reported as an oncogene by regulating p16 and p19, which are cell cycle inhibitor genes. Bmi1 knockout in mice results in defects in hematopoiesis, skeletal patterning, neurological functions, and development of the cerebellum. Recently it has been reported that BMI1 is rapidly recruited to sites of DNA damage, where it sustains for over 8h. Loss of BMI1 leads to radiation sensitive and impaired repair of DNA double-strand breaks by homologous recombination. Bmi1 is necessary for efficient self-renewing cell divisions of adult hematopoietic stem cells as well as adult peripheral and central nervous system neural s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PHC1
Polyhomeotic-like protein 1 is a protein that in humans is encoded by the ''PHC1'' gene. Function This gene is a homolog of the ''Drosophila'' polyhomeotic gene, which is a member of the Polycomb group of genes. The gene product is a component of a multimeric protein complex that contains EDR2 and the vertebrate Polycomb protein BMI1. The gene product, the EDR2 protein, and the ''Drosophila'' polyhomeotic protein share two highly conserved domains, named homology domains I and II. These domains are involved in protein–protein interactions and may mediate heterodimerization of the protein encoded by this gene and the EDR2 protein. Mutations in this gene have been associated to cases of primary microcephaly. Interactions PHC1 has been shown to interact with BMI1 and PHC2 Polyhomeotic-like protein 2 is a protein that in humans is encoded by the ''PHC2'' gene. Function In Drosophila melanogaster, the 'Polycomb' group (PcG) of genes are part of a cellular memory system t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polycomb Recruitment In X Chromosome Inactivation
X chromosome inactivation (XCI) is the phenomenon that has been selected during the evolution to balance X-linked gene dosage between XX females and XY males. Phases XCI is usually divided in two phases, the establishment phase when gene silencing is reversible, and maintenance phase when gene silencing becomes irreversible. During the establishment phase of X Chromosome Inactivation (XCI), Xist RNA, the master regulator of this process, is monoallelically upregulated and it spreads ''in cis'' along the future inactive X (Xi), relocates to the nuclear periphery. and recruits repressive chromatin-remodelling complexes Among these, Xist recruits proteins of the Polycomb repressive complexes. Whether Xist directly recruits Polycomb repressive complex 2 (PRC2) to the chromatin or this recruitment is the consequence of Xist-mediated changes on the chromatin has been object of intense debate. Mechanism Some studies showed that PRC2 components are not associated with Xist RNA ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bivalent Chromatin
Bivalent chromatin are segments of DNA, bound to histone proteins, that have both repressing and activating epigenetic regulators in the same region. These regulators work to enhance or silence the expression of genes. Since these regulators work in opposition to each other, they normally interact with chromatin at different times. However, in bivalent chromatin, both types of regulators are interacting with the same domain at the same time. Bivalent chromatin domains are normally associated with promoters of transcription factor genes that are expressed at low levels. Bivalent domains have also been found to play a role in developmental regulation in pluripotent embryonic stems cells, gene imprinting and cancer. Bivalent epigenetic regulators The most common antagonistic epigenetic regulators found together on bivalent chromatin domains are methylation marks on histone 3 lysine 4 (H3K4me3) and histone 3 lysine 27 (H3K27me3). The H3K27me3 mark silences the gene while the H3K4me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromatin
Chromatin is a complex of DNA and protein found in eukaryotic cells. The primary function is to package long DNA molecules into more compact, denser structures. This prevents the strands from becoming tangled and also plays important roles in reinforcing the DNA during cell division, preventing DNA damage, and regulating gene expression and DNA replication. During mitosis and meiosis, chromatin facilitates proper segregation of the chromosomes in anaphase; the characteristic shapes of chromosomes visible during this stage are the result of DNA being coiled into highly condensed chromatin. The primary protein components of chromatin are histones. An octamer of two sets of four histone cores (Histone H2A, Histone H2B, Histone H3, and Histone H4) bind to DNA and function as "anchors" around which the strands are wound.Maeshima, K., Ide, S., & Babokhov, M. (2019). Dynamic chromatin organization without the 30-nm fiber. ''Current opinion in cell biology, 58,'' 95–104. https://doi.o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polycomb Repressive Complex 1
Polycomb repressive complex 1 (PRC1) is one of the two classes of Polycomb Repressive complexes, the other being PRC2. Polycomb-group proteins play a major role in transcriptional regulation during development. Polycomb Repressive Complexes PRC1 and PRC2 function in the silencing of expression of the Hox gene network involved in development as well as the inactivation of the X chromosome. PRC1 inhibits the activated form of RNA polymerase II preinitiation complex with the use of H3K27me. PRC1 binds to three nucleosomes, this is believed to limit access of transcription factors to the chromatin, and therefore limit gene expression Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product that enables it to produce end products, protein or non-coding RNA, and ultimately affect a phenotype, as the final effect. The ....{{Cite journal, last1=Lehmann, first1=Lynn, last2=Ferrari, first2=Roberto, last3=Vashisht, first3=Aj ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hox Gene
Hox genes, a subset of homeobox genes, are a group of related genes that specify regions of the body plan of an embryo along the head-tail axis of animals. Hox proteins encode and specify the characteristics of 'position', ensuring that the correct structures form in the correct places of the body. For example, Hox genes in insects specify which appendages form on a segment (for example, legs, antennae, and wings in fruit flies), and Hox genes in vertebrates specify the types and shape of vertebrae that will form. In segmented animals, Hox proteins thus confer segmental or positional identity, but do not form the actual segments themselves. Studies on Hox genes in ciliated larvae have shown they are only expressed in future adult tissues. In larvae with gradual metamorphosis the Hox genes are activated in tissues of the larval body, generally in the trunk region, that will be maintained through metamorphosis. In larvae with complete metamorphosis the Hox genes are mainly express ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vernalization
Vernalization (from Latin ''vernus'', "of the spring") is the induction of a plant's flowering process by exposure to the prolonged cold of winter, or by an artificial equivalent. After vernalization, plants have acquired the ability to flower, but they may require additional seasonal cues or weeks of growth before they will actually flower. The term is sometimes used to refer to the need of herbal (non-woody) plants for a period of cold dormancy in order to produce new shoots and leaves, but this usage is discouraged. Many plants grown in temperate climates require vernalization and must experience a period of low winter temperature to initiate or accelerate the flowering process. This ensures that reproductive development and seed production occurs in spring and winters, rather than in autumn. The needed cold is often expressed in chill hours. Typical vernalization temperatures are between 1 and 7 degrees Celsius (34 and 45 degrees Fahrenheit). For many perennial plants, such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flowering Locus C
Flowering Locus C (''FLC'') is a MADS-box gene that in late-flowering ecotypes of the plant '' Arabidopsis thaliana'' is responsible for vernalization. In a new seedling ''FLC'' is expressed, which prevents flowering. Upon exposure to cold, less ''FLC'' is expressed (to a degree depending on the amount of cold), and flowering becomes possible. ''FLC'' is extensively regulated through epigenetic modifications and transcriptional control. The expression of ''FLC'' is affected by other genes including '' FLK'', '' FCA'' and '' VERNALIZATION2'' (''VRN2''). Wild ''Arabidopsis'' plants have different allele An allele (, ; ; modern formation from Greek ἄλλος ''állos'', "other") is a variation of the same sequence of nucleotides at the same place on a long DNA molecule, as described in leading textbooks on genetics and evolution. ::"The chro ...s for the ''FLC'' gene, which correspond to ecotypes which either (a) flower rapidly and produce a number of generations during one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DEV035048A
Dev, sometimes capitalized as DEV, can be referred as: People Single names * Dev (born 1982), Indian actor * Dev (born 1984), British radio presenter, DJ and actor * Dev (born 1989), American singer * Dev, Indian actor First names * Dev Anand (1923–2011), Indian actor * Dev Griffin (born 1984), British DJ * Dev Hynes (born 1985), British musician * Dev Kumar (born 1972), Indian writer * Dev Patel (born 1990), British actor Surnames * Aditya Dev (born 1988), Indian body builder with dwarfism * Ajinkya Dev, Indian actor * Angad Dev (1504–1552), Sikh guru * Arjan Dev (1563–1606), Sikh guru * Deepak Dev (born 1978), Indian composer * Gokul Inder Dev (born 1938), Indian cricketer * Govinda Chandra Dev (1907–1971), Bangladeshi philosophy professor * I. H. Sangam Dev, Indian investigative journalist * K. J. Kapil Dev, Indian volleyball player * Kanhad Dev (fl. 1298–1299), Indian maharaja * Kapil Dev (born 1959), Indian cricketer * Mukul Dev, Indian actor * Nanak Dev (14 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Egg Cell
The egg cell, or ovum (plural ova), is the female reproductive cell, or gamete, in most anisogamous organisms (organisms that reproduce sexually with a larger, female gamete and a smaller, male one). The term is used when the female gamete is not capable of movement (non-motile). If the male gamete (sperm) is capable of movement, the type of sexual reproduction is also classified as oogamous. A nonmotile female gamete formed in the oogonium of some algae, fungi, oomycetes, or bryophytes is an oosphere. When fertilized the oosphere becomes the oospore. When egg and sperm fuse during fertilisation, a diploid cell (the zygote) is formed, which rapidly grows into a new organism. History While the non-mammalian animal egg was obvious, the doctrine ''ex ovo omne vivum'' ("every living nimal comes froman egg"), associated with William Harvey (1578–1657), was a rejection of spontaneous generation and preformationism as well as a bold assumption that mammals also reproduced via ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
