The process by which the CELL NUCLEUS is divided.
Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.
Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)
Facilities which provide information concerning poisons and treatment of poisoning in emergencies.
A subtype of striated muscle, attached by TENDONS to the SKELETON. Skeletal muscles are innervated and their movement can be consciously controlled. They are also called voluntary muscles.
The membrane system of the CELL NUCLEUS that surrounds the nucleoplasm. It consists of two concentric membranes separated by the perinuclear space. The structures of the envelope where it opens to the cytoplasm are called the nuclear pores (NUCLEAR PORE).
Specific particles of membrane-bound organized living substances present in eukaryotic cells, such as the MITOCHONDRIA; the GOLGI APPARATUS; ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.
Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.
A plant genus of the family Apocynaceae. It is the source of VINCA ALKALOIDS, used in leukemia chemotherapy.
Compounds formed by condensation of secologanin with tryptamine resulting in a tetrahydro-beta-carboline which is processed further to a number of bioactive compounds. These are especially found in plants of the APOCYNACEAE; LOGANIACEAE; and RUBIACEAE families.
One of the Indian Ocean Islands off the southeast coast of Africa. Its capital is Antananarivo. It was formerly called the Malagasy Republic. Discovered by the Portuguese in 1500, its history has been tied predominantly to the French, becoming a French protectorate in 1882, a French colony in 1896, and a territory within the French union in 1946. The Malagasy Republic was established in the French Community in 1958 but it achieved independence in 1960. Its name was changed to Madagascar in 1975. (From Webster's New Geographical Dictionary, 1988, p714)
A type of CELL NUCLEUS division by means of which the two daughter nuclei normally receive identical complements of the number of CHROMOSOMES of the somatic cells of the species.
A plant genus of the family APOCYNACEAE. Vinca rosea has been changed to CATHARANTHUS roseus.
New abnormal growth of tissue. Malignant neoplasms show a greater degree of anaplasia and have the properties of invasion and metastasis, compared to benign neoplasms.

The arithmetic of centrosome biogenesis. (1/86)

How do cells regulate centrosome number? A canonical duplication cycle generates two centrosomes from one in most proliferating cells. Centrioles are key to this process, and molecules such as centrins, SAS-4 and ZYG-1 govern daughter centriole formation. Cdk2 activity probably couples centrosome duplication with the S phase, and a licensing mechanism appears to limit centrosome duplication to once per cell cycle. However, such mechanisms must be altered in some cells--for example, spermatocytes--in which centrosome duplication and DNA replication are uncoupled. There are also alternative pathways of centrosome biogenesis. For example, one centrosome is reconstituted from two gametes at fertilization; in this case, the most common strategy involves differential contributions of centrioles and pericentriolar material (PCM) from each gamete. Furthermore, centrioles can sometimes form de novo from no apparent template. This occurs, for instance, in the early mouse embryo and in parthenogenetic species and might rely on a pre-existing seed that resides within PCM but is not visible by ultrastructural analysis.  (+info)

Cell cycle-dependent nuclear localization of yeast RNase III is required for efficient cell division. (2/86)

Members of the double-stranded RNA-specific ribonuclease III (RNase III) family were shown to affect cell division and chromosome segregation, presumably through an RNA interference-dependent mechanism. Here, we show that in Saccharomyces cerevisiae, where the RNA interference machinery is not conserved, an orthologue of RNase III (Rnt1p) is required for progression of the cell cycle and nuclear division. The deletion of Rnt1p delayed cells in both G1 and G2/M phases of the cell cycle. Nuclear division and positioning at the bud neck were also impaired in Deltarnt1 cells. The cell cycle defects were restored by the expression of catalytically inactive Rnt1p, indicating that RNA cleavage is not essential for cell cycle progression. Rnt1p was found to exit from the nucleolus to the nucleoplasm in the G2/M phase, and perturbation of its localization pattern delayed the progression of cell division. A single mutation in the Rnt1p N-terminal domain prevented its accumulation in the nucleoplasm and slowed exit from mitosis without any detectable effects on RNA processing. Together, the data reveal a new role for a class II RNase III in the cell cycle and suggest that at least some members of the RNase III family possess catalysis-independent functions.  (+info)

Thiamine prevents X-ray induction of genetic changes in human lymphocytes in vitro. (3/86)

The effects of thiamine (vitamin B1) on the level of spontaneous or radiation-induced genetic changes in human lymphocytes in vitro were studied. Cultured lymphocytes were exposed to increasing concentrations of thiamine (0-500 microg/ml) and irradiated with X-rays. The DNA damage was estimated as the frequency of micronuclei and apoptotic or necrotic morphological changes in fixed cells. The results show that thiamine alone did not induce genetic changes. A significant decrease in the fraction of apoptotic and necrotic cells was observed in lymphocytes irradiated in the presence of vitamin B1 at concentrations between 1-100 microg/ml compared to those irradiated in the absence of thiamine. Vitamin B1 at 1 and 10 microg/ml decreased also the extent of radiation-induced formation of micronuclei. Vitamin B1 had no effect on radiation-induced cytotoxicity as measured by nuclear division index. The results indicate that vitamin B1 protects human cells from radiation-induced genetic changes.  (+info)

A beta-tubulin mutation selectively uncouples nuclear division and cytokinesis in Tetrahymena thermophila. (4/86)

The ciliated protozoan Tetrahymena thermophila contains two distinct nuclei within a single cell-the mitotic micronucleus and the amitotic macronucleus. Although microtubules are required for proper division of both nuclei, macronuclear chromosomes lack centromeres and the role of microtubules in macronuclear division has not been established. Here we describe nuclear division defects in cells expressing a mutant beta-tubulin allele that confers hypersensitivity to the microtubule-stabilizing drug paclitaxel. Macronuclear division is profoundly affected by the btu1-1 (K350M) mutation, producing cells with widely variable DNA contents, including cells that lack macronuclei entirely. Protein expressed by the btu1-1 allele is dominant over wild-type protein expressed by the BTU2 locus. Normal macronuclear division is restored when the btu1-1 allele is inactivated by targeted disruption or expressed as a truncated protein. Immunofluorescence studies reveal elongated microtubular structures that surround macronuclei that fail to migrate to the cleavage furrows. In contrast, other cytoplasmic microtubule-dependent processes, such as cytokinesis, cortical patterning, and oral apparatus assembly, appear to be unaffected in the mutant. Micronuclear division is also perturbed in the K350M mutant, producing nuclei with elongated early-anaphase spindle configurations that persist well after the initiation of cytokinesis. The K350M mutation affects tubulin dynamics, as the macronuclear division defect is exacerbated by three treatments that promote microtubule polymerization: (i) elevated temperatures, (ii) sublethal concentrations of paclitaxel, and (iii) high concentrations of dimethyl sulfoxide. Inhibition of phosphatidylinositol 3-kinase (PI 3-kinase) with 3-methyladenine or wortmannin also induces amacronucleate cell formation in a btu1-1-dependent manner. Conversely, the myosin light chain kinase inhibitor ML-7 has no effect on nuclear division in the btu1-1 mutant strain. These findings provide new insights into microtubule dynamics and link the evolutionarily conserved PI 3-kinase signaling pathway to nuclear migration and/or division in Tetrahymena.  (+info)

A mitotic kinesin-like protein required for normal karyokinesis, myosin localization to the furrow, and cytokinesis in Dictyostelium. (5/86)

Dictyostelium mitotic kinesin Kif12 is required for cytokinesis. Myosin II localization to the cleavage furrow is severely depressed in Kif12-null (Deltakif12) cells, which accounts in part for the cytokinesis failure. Myosin II-null cells, however, undergo mitosis-coupled cytokinesis when adhering to a surface, whereas the Deltakif12 cells cannot. During mitosis, the rate of change of internuclear separation in Deltakif12 cells is reduced compared with wild-type cells, indicating multiple roles of this molecular motor during mitosis and cytokinesis. GFP-Kif12, which rescues wild-type behavior when expressed in the Deltakif12 strain, is concentrated in the nucleus in interphase cells, translocates to the cytoplasm at the onset of mitosis, appears in the centrosomes and spindle, and later is concentrated in the spindle midbody. Given these results, we hypothesize a mechanism for myosin II translocation to the furrow to set up the contractile ring.  (+info)

A requirement for breast-cancer-associated gene 1 (BRCA1) in the spindle checkpoint. (6/86)

BRCA1-associated breast cancer exhibits significantly higher levels of chromosomal abnormalities than sporadic breast cancers. However, the molecular mechanisms regarding the roles of BRCA1 in maintaining genome integrity remain elusive. By using a mouse model deficient for Brca1 full-length isoform (Brca1(Delta11/Delta11)), we found that Brca1(Delta11/Delta11) cells displayed decreased expression of a number of genes that are involved in the spindle checkpoint, including Mad2, which is a key component of spindle checkpoint that inhibits anaphase-promoting complex. We showed that Brca1(Delta11/Delta11) cells failed to arrest at metaphase in the presence of nocodazole and underwent apoptosis because of activation of p53. Consistently, reconstitution of Mad2 in Brca1(Delta11/Delta11) cells partially restored the spindle checkpoint and attenuated apoptosis. By using UBR60 cells, which carry tetracycline-regulated expression of BRCA1, we demonstrated that BRCA1 binds to transcription factor OCT-1 and up-regulates the transcription of MAD2. Furthermore, we showed that the induction of BRCA1 to endogenous MAD2 or transfected MAD2 luciferase reporter in UBR60 cells was completely inhibited by acute suppression of BRCA1 by RNA interference. These data reveal a role of BRCA1 in maintaining genome integrity by interplaying with p53 and genes that are involved in the spindle checkpoint and apoptosis.  (+info)

Rendez-vous at mitosis: TRRAPed in the chromatin. (7/86)

Cell cycle progression and cell cycle checkpoints are guided by dynamic changes in gene expression that requires concerted efforts of chromatin modifying/remodeling activities and transcription machinery. Epigenetic modifications including acetylation of specific lysine residues within the amino-terminal tails of core histones play an important role in these processes. In the last few years, a flurry of biochemical studies has identified numerous histone acetyltransferases (HAT) whose activity is dependent on the multiprotein assemblies and responsible for histone acetylation. In addition to their well-known involvement in the control of gene transcription, recent studies implicated HATs and histone acetylation in other important cellular processes, such as DNA replication, cell cycle control, DNA repair and genomic stability. With the exception of catalytic subunits of the HAT assemblies, the role of other components of these large multi-subunit complexes in cellular processes remains largely unknown. Recent genetic and cellular studies have shown that Trrap, a common component of HAT complexes, regulates the mitotic checkpoint function by modulation of mitotic checkpoint genes. This regulation involves a concerted and cell cycle stage-coupled recruitment of HAT activity to promoters of specific checkpoint genes, providing a functional link between specific chromatin modifications and cell cycle control. These findings shed new light on the role of HAT components and histone acetylation in cell cycle control and underscore functional significance of epigenetic modifications in cellular processes.  (+info)

A novel mechanism of nuclear envelope break-down in a fungus: nuclear migration strips off the envelope. (8/86)

In animals, the nuclear envelope disassembles in mitosis, while budding and fission yeast form an intranuclear spindle. Ultrastructural data indicate that basidiomycetes, such as the pathogen Ustilago maydis, undergo an 'open mitosis'. Here we describe the mechanism of nuclear envelope break-down in U. maydis. In interphase, the nucleus resides in the mother cell and the spindle pole body is inactive. Prior to mitosis, it becomes activated and nucleates microtubules that reach into the daughter cell. Dynein appears at microtubule tips and exerts force on the spindle pole body, which leads to the formation of a long nuclear extension that reaches into the bud. Chromosomes migrate through this extension and together with the spindle pole bodies leave the old envelope, which remains in the mother cell until late telophase. Inhibition of nuclear migration or deletion of a Tem1p-like GTPase leads to a 'closed' mitosis, indicating that spindle pole bodies have to reach into the bud where MEN signalling participates in envelope removal. Our data indicate that dynein-mediated premitotic nuclear migration is essential for envelope removal in U. maydis.  (+info)

Cell nucleus division, also known as nuclear division, is the process by which the genetic material within the cell nucleus, referred to as chromosomes, is separated into two equal sets in preparation for cell division. This process results in the formation of two daughter nuclei, each with a complete set of chromosomes.

There are two types of nuclear division: mitosis and meiosis.

Mitosis is the type of nuclear division that occurs in somatic cells (cells other than sex cells) during growth, repair, and maintenance of tissues. It results in the formation of two genetically identical daughter nuclei. The process of mitosis can be divided into several stages: prophase, prometaphase, metaphase, anaphase, and telophase.

Meiosis, on the other hand, is the type of nuclear division that occurs in sex cells (sperm and egg cells) during sexual reproduction. It results in the formation of four genetically unique daughter nuclei, each with half the number of chromosomes as the parent cell. Meiosis consists of two consecutive divisions: meiosis I and meiosis II.

Both types of nuclear division are essential for the growth, development, and reproduction of living organisms.

The cell nucleus is a membrane-bound organelle found in the eukaryotic cells (cells with a true nucleus). It contains most of the cell's genetic material, organized as DNA molecules in complex with proteins, RNA molecules, and histones to form chromosomes.

The primary function of the cell nucleus is to regulate and control the activities of the cell, including growth, metabolism, protein synthesis, and reproduction. It also plays a crucial role in the process of mitosis (cell division) by separating and protecting the genetic material during this process. The nuclear membrane, or nuclear envelope, surrounding the nucleus is composed of two lipid bilayers with numerous pores that allow for the selective transport of molecules between the nucleoplasm (nucleus interior) and the cytoplasm (cell exterior).

The cell nucleus is a vital structure in eukaryotic cells, and its dysfunction can lead to various diseases, including cancer and genetic disorders.

Cell division is the process by which a single eukaryotic cell (a cell with a true nucleus) divides into two identical daughter cells. This complex process involves several stages, including replication of DNA, separation of chromosomes, and division of the cytoplasm. There are two main types of cell division: mitosis and meiosis.

Mitosis is the type of cell division that results in two genetically identical daughter cells. It is a fundamental process for growth, development, and tissue repair in multicellular organisms. The stages of mitosis include prophase, prometaphase, metaphase, anaphase, and telophase, followed by cytokinesis, which divides the cytoplasm.

Meiosis, on the other hand, is a type of cell division that occurs in the gonads (ovaries and testes) during the production of gametes (sex cells). Meiosis results in four genetically unique daughter cells, each with half the number of chromosomes as the parent cell. This process is essential for sexual reproduction and genetic diversity. The stages of meiosis include meiosis I and meiosis II, which are further divided into prophase, prometaphase, metaphase, anaphase, and telophase.

In summary, cell division is the process by which a single cell divides into two daughter cells, either through mitosis or meiosis. This process is critical for growth, development, tissue repair, and sexual reproduction in multicellular organisms.

An encyclopedia is a comprehensive reference work containing articles on various topics, usually arranged in alphabetical order. In the context of medicine, a medical encyclopedia is a collection of articles that provide information about a wide range of medical topics, including diseases and conditions, treatments, tests, procedures, and anatomy and physiology. Medical encyclopedias may be published in print or electronic formats and are often used as a starting point for researching medical topics. They can provide reliable and accurate information on medical subjects, making them useful resources for healthcare professionals, students, and patients alike. Some well-known examples of medical encyclopedias include the Merck Manual and the Stedman's Medical Dictionary.

Poison Control Centers are specialized organizations that provide immediate, free, and expert advice and treatment recommendations for exposure to potentially harmful substances, also known as poisons. They are staffed by trained healthcare professionals, including medical toxicologists, nurses, pharmacists, and poison information providers. These centers manage a wide range of poisoning cases, from accidental ingestions in children to intentional overdoses and chemical exposures in adults. They offer 24/7 emergency hotline services to the public, healthcare providers, and first responders for poison-related emergencies and provide valuable resources for poison prevention and education. The primary goal of Poison Control Centers is to reduce the morbidity and mortality associated with poison exposures and promote overall public health and safety.

Skeletal muscle, also known as striated or voluntary muscle, is a type of muscle that is attached to bones by tendons or aponeuroses and functions to produce movements and support the posture of the body. It is composed of long, multinucleated fibers that are arranged in parallel bundles and are characterized by alternating light and dark bands, giving them a striped appearance under a microscope. Skeletal muscle is under voluntary control, meaning that it is consciously activated through signals from the nervous system. It is responsible for activities such as walking, running, jumping, and lifting objects.

The nuclear envelope is a complex and double-membrane structure that surrounds the eukaryotic cell's nucleus. It consists of two distinct membranes: the outer nuclear membrane, which is continuous with the endoplasmic reticulum (ER) membrane, and the inner nuclear membrane, which is closely associated with the chromatin and nuclear lamina.

The nuclear envelope serves as a selective barrier between the nucleus and the cytoplasm, controlling the exchange of materials and information between these two cellular compartments. Nuclear pore complexes (NPCs) are embedded in the nuclear envelope at sites where the inner and outer membranes fuse, forming aqueous channels that allow for the passive or active transport of molecules, such as ions, metabolites, and RNA-protein complexes.

The nuclear envelope plays essential roles in various cellular processes, including DNA replication, transcription, RNA processing, and chromosome organization. Additionally, it is dynamically regulated during the cell cycle, undergoing disassembly and reformation during mitosis to facilitate equal distribution of genetic material between daughter cells.

Organelles are specialized structures within cells that perform specific functions essential for the cell's survival and proper functioning. They can be thought of as the "organs" of the cell, and they are typically membrane-bound to separate them from the rest of the cellular cytoplasm. Examples of organelles include the nucleus (which contains the genetic material), mitochondria (which generate energy for the cell), ribosomes (which synthesize proteins), endoplasmic reticulum (which is involved in protein and lipid synthesis), Golgi apparatus (which modifies, sorts, and packages proteins and lipids for transport), lysosomes (which break down waste materials and cellular debris), peroxisomes (which detoxify harmful substances and produce certain organic compounds), and vacuoles (which store nutrients and waste products). The specific organelles present in a cell can vary depending on the type of cell and its function.

Erythrocytes, also known as red blood cells (RBCs), are the most common type of blood cell in circulating blood in mammals. They are responsible for transporting oxygen from the lungs to the body's tissues and carbon dioxide from the tissues to the lungs.

Erythrocytes are formed in the bone marrow and have a biconcave shape, which allows them to fold and bend easily as they pass through narrow blood vessels. They do not have a nucleus or mitochondria, which makes them more flexible but also limits their ability to reproduce or repair themselves.

In humans, erythrocytes are typically disc-shaped and measure about 7 micrometers in diameter. They contain the protein hemoglobin, which binds to oxygen and gives blood its red color. The lifespan of an erythrocyte is approximately 120 days, after which it is broken down in the liver and spleen.

Abnormalities in erythrocyte count or function can lead to various medical conditions, such as anemia, polycythemia, and sickle cell disease.

'Catharanthus' is a genus of plants in the Apocynaceae family, commonly known as the dogbane family. The most well-known species is Catharanthus roseus, also known as Madagascar periwinkle or rosy periwinkle. This plant contains alkaloids that have been used in the production of drugs for cancer treatment. Vincristine and vinblastine are two such alkaloids derived from C. roseus, which have shown significant anti-cancer properties and are used to treat various types of cancers, including leukemia and lymphoma.

It is important to note that the use of Catharanthus or its derivatives should be under medical supervision due to their potent biological activities and potential side effects.

Secologanin tryptamine alkaloids are a type of alkaloid compound that is derived from the combination of secologanin (a metabolite found in certain plants) and tryptamine (an organic compound that is a building block for several neurotransmitters). These alkaloids have been identified in various plant species, including those in the genera *Psychotria* and *Uncaria*, and are known to exhibit a range of pharmacological activities. Some examples of secologanin tryptamine alkaloids include ajmalicine, reserpine, and yohimbine, which have been used in traditional medicine for their sedative, antihypertensive, and aphrodisiac properties, respectively. However, it is important to note that these compounds can also have toxic effects and should only be used under the guidance of a medical professional.

I'm sorry for any confusion, but "Madagascar" is not a medical term. It is actually the fourth-largest island country in the world, located in the Indian Ocean, off the southeastern coast of Africa. If you have any questions about medical terms or concepts, I'd be happy to help answer those!

Mitosis is a type of cell division in which the genetic material of a single cell, called the mother cell, is equally distributed into two identical daughter cells. It's a fundamental process that occurs in multicellular organisms for growth, maintenance, and repair, as well as in unicellular organisms for reproduction.

The process of mitosis can be broken down into several stages: prophase, prometaphase, metaphase, anaphase, and telophase. During prophase, the chromosomes condense and become visible, and the nuclear envelope breaks down. In prometaphase, the nuclear membrane is completely disassembled, and the mitotic spindle fibers attach to the chromosomes at their centromeres.

During metaphase, the chromosomes align at the metaphase plate, an imaginary line equidistant from the two spindle poles. In anaphase, sister chromatids are pulled apart by the spindle fibers and move toward opposite poles of the cell. Finally, in telophase, new nuclear envelopes form around each set of chromosomes, and the chromosomes decondense and become less visible.

Mitosis is followed by cytokinesis, a process that divides the cytoplasm of the mother cell into two separate daughter cells. The result of mitosis and cytokinesis is two genetically identical cells, each with the same number and kind of chromosomes as the original parent cell.

"Vinca" is not a medical term itself, but it refers to a group of plants that belong to the genus Vinca or the family Apocynaceae. Some species of Vinca are used in medicine and are known as "vinca alkaloids." These alkaloids include vincristine and vinblastine, which have been isolated from the Madagascar periwinkle (Vinca rosea) plant.

Vincristine and vinblastine are antimicrotubule agents that disrupt microtubule function during mitosis, leading to cell cycle arrest and apoptosis (programmed cell death). They have been used in the treatment of various types of cancer, including leukemias, lymphomas, and testicular cancer.

Therefore, when referring to "Vinca" in a medical context, it typically means the use of vinca alkaloids as anticancer agents.

Neoplasms are abnormal growths of cells or tissues in the body that serve no physiological function. They can be benign (non-cancerous) or malignant (cancerous). Benign neoplasms are typically slow growing and do not spread to other parts of the body, while malignant neoplasms are aggressive, invasive, and can metastasize to distant sites.

Neoplasms occur when there is a dysregulation in the normal process of cell division and differentiation, leading to uncontrolled growth and accumulation of cells. This can result from genetic mutations or other factors such as viral infections, environmental exposures, or hormonal imbalances.

Neoplasms can develop in any organ or tissue of the body and can cause various symptoms depending on their size, location, and type. Treatment options for neoplasms include surgery, radiation therapy, chemotherapy, immunotherapy, and targeted therapy, among others.

Anucleated cells can also arise from flawed cell division in which one daughter lacks a nucleus and the other has two nuclei. ... Eukaryotic cells usually have a single nucleus, but a few cell types, such as mammalian red blood cells, have no nuclei, and a ... "The Nucleus". MBInfo. "Learn about the Cell Nucleus". cellnucleus.com. Website covering structure and function of the nucleus ... having already described cells multiplying by division and believing that many cells would have no nuclei. The idea that cells ...
... nucleus and cell division). On the basis of his discoveries, Flemming surmised for the first time that all cell nuclei came ... Flemming investigated the process of cell division and the distribution of chromosomes to the daughter nuclei, a process he ... He identified that chromatin was correlated to threadlike structures in the cell nucleus - the chromosomes (meaning coloured ... Lukács (1981). "Walter Flemming, discoverer of chromatin and mitotic cell division". Orvosi Hetilap. 122 (6): 349-50. PMID ...
Prior to cell division, the nucleus undergoes mitosis. The ploidy of Cryptoglena has not been investigated (although it is ... The cells of Cryptoglena resemble a coffee bean, as they have a groove that runs the length of the cell on one side and makes ... In the posterior region of the cells lies the nucleus, which contains the chromatin that remains permanently condensed and ... The U-shape allows for the chloroplast's volume to increase directly with cell volume. In some cells the chloroplast can almost ...
mitochondria mitosis In eukaryotic cells, the part of the cell cycle during which the division of the nucleus takes place and ... cell nucleus The "control room" for the cell. The nucleus gives out all the orders. cell plate Grown in the cell's center, it ... creating a new cell wall that enables cell division. cell theory The theory that all living things are made up of cells. cell ... cell division Any process by which a parent cell divides into two or more daughter cells. Examples include binary fission, ...
Cell division becomes uncontrolled. Cell nuclei become less uniform. Pathologists describe cells as well differentiated (low- ... One of the hallmarks of cancer is that cells divide uncontrollably. The more cells that are dividing, the worse the cancer. ... The closer the appearance of the cancer cells to normal cells, the slower their growth and the better the prognosis. If cells ... and irregular nuclei and pleomorphic changes are signs of abnormal cell reproduction. Note: The cancer areas having cells with ...
Cell division becomes uncontrolled. Cell nuclei become less uniform. Pathologists describe cells as well differentiated (low ... Normal cells divide as many times as needed and stop. They attach to other cells and stay in place in tissues. Cells become ... Normal cells will self-destruct (programmed cell death) when they are no longer needed. Until then, cells are protected from ... Abnormal growth factor signaling in the interaction between stromal cells and epithelial cells can facilitate malignant cell ...
During cell division, the nucleus and chromosomes elongate longitudinally. A constriction forms in the middle of the nucleus ... and plays a role in cell division. In Holomastigotoides cells, there is a high concentration of centrin at the apex of the cell ... The number of flagellar bands in a daughter cell is determined by duplication of basal bodies at the end of cell division. The ... The nucleus of Holomastigotoides is located in the anterior apex of the cell, and is associated with a mitotic spindle located ...
Second, it has two cell nuclei. The larger, called the "macronucleus", carries out the normal work of the cell by transcribing ... First, it reproduces both by cell division (splitting one cell into two) and by conjugation, in which two organisms temporarily ... It is spread by cell division of Halofolliculina corallasia, which produces a pair of worm-like larvae that settle on undamaged ... The smaller "micronucleus" is used only for reproducing the organism by cell division and by conjugation. And third, it has ...
Stage of cell division Mitosis - Process in which replicated chromosomes are separated into two new identical nuclei Cell ... doubled cell wall between plant daughter cells. It divides the cell into two daughter cells. Cytokinesis largely resembles the ... is the part of the cell division process during which the cytoplasm of a single eukaryotic cell divides into two daughter cells ... Final stage of a cell division for eukaryotic cells both in mitosis and meiosis Prophase - First phase of cell division in both ...
... has a cell wall, nucleus, pyrenoid, and spiral chloroplasts. Spirogyra can reproduce both sexually and asexually. In ... and Spirogyra simply undergoes intercalary cell division to extend the length of the new filaments. Sexual reproduction is of ... One cell each from opposite lined filaments emits tubular protuberances known as conjugation tubes, which elongate and fuse to ... Two adjoining cells near the common transverse wall give out protuberances known as conjugation tubes, which further form the ...
They then divide into ascending and descending fibers. The latter end by arborizing around the cells of the medial nucleus, ... Some of the axons of the cells of the lateral nucleus, and possibly also of the medial nucleus, are continued upward through ... Fibers from the lateral vestibular nucleus also pass via the vestibulospinal tract, to anterior horn cells at many levels in ... The vestibular nuclei (VN) are the cranial nuclei for the vestibular nerve located in the brainstem. In Terminologia Anatomica ...
Type A (pale) cells, with pale nuclei. These are the spermatogonial stem cells that undergo active mitosis. These cells divide ... There are three subtypes of spermatogonia in humans: Type A (dark) cells, with dark nuclei. These cells are reserve ... v t e (Articles with short description, Short description matches Wikidata, Germ cells, All stub articles, Cell biology stubs) ... Type B cells, which undergo growth and become primary spermatocytes. Anticancer drugs such as doxorubicin and vincristine can ...
Cells reproduce through a process of cell division in which the parent cell divides into two or more daughter cells. For ... providing each cell its own complete set of chromosomes. Eukaryotes store most of their DNA inside the cell nucleus. Cells are ... and all cells arise from pre-existing cells by division. Cell theory was formulated by Henri Dutrochet, Theodor Schwann, Rudolf ... Cells contain hereditary information that is carried forward as a genetic code during cell division. There are two primary ...
The nucleus typically lies in the posterior half of the cell. The mitochondria have tubular cristae. Organelles called ... Members of this genus are known to reproduce asexually through cell division. Whether sexual reproduction occurs is currently ... The cell shape is variable but is mostly obovoid to ellipsoid. The lateral cell margins maybe somewhat angular leading to a ... Provided with a nucleus and contracting vesicles. - Carter, 1865 In 1917, it was classified as being one of the "simplest and ...
The nucleus is large, ovoid and occupies most of the cell. Some basal cells can act like stem cells with the ability to divide ... Not all basal-cell cancers originate in the basal cells but they are so named because the cancer cells resemble basal cells ... pigment-producing cells) and Merkel cells (touch receptors). Basal-cell carcinomas (basal-cell cancers), account for around 80 ... The stratum basale is a single layer of columnar or cuboidal basal cells. The cells are attached to each other and to the ...
... divides and a curved row of 5 or 6 cells is formed. The penultimate cell of this row contains two large nuclei; while the other ... The nucleus of the ascus finally divides three times, producing the nuclei of the eight ascospores; which subsequently are ... cells of the row have one nucleus each. The young ascus develops from this penultimate cell in which the two nuclei fuse ... The cell wall between these organs is dissolved at the time of fertilization and the male and female nuclei unite, and a fresh ...
Zimmermann later identified Karsten's "nucleus" as the cell's pyrenoid, based on its characteristic position within the ... Like many other cryptomonads, Rhodomonas reproduces through asexual division. It is not currently known if they are capable of ... Rhodomonas are motile cells, attributed to the presence of two flagella extending at the anterior end of the cell that allow ... The posterior edges of the internal periplast plates taper towards the posterior end of the cell and attach to the cell ...
In contrast, other commonly used non-viral transfection methods rely on cell division for the transfer of DNA into the nucleus ... Non-viral delivery methods may require cell division for completion of transfection, since the DNA enters the nucleus during ... Primary cells, for example stem cells, especially fall into this category, although many other cell lines are also difficult to ... with cell-type specific reagents. The substrate is transferred directly into the cell nucleus and the cytoplasm. ...
... is the major component in forming cell membranes, enables smooth cell division, and removes harmful substances by binding with ... Phosphoric acid makes up part of the cell nucleus and reproductive system. Phosphoric acid is involved in photo phosphorylation ... Deficiency hinders cell division and reproduction. Symptoms first appear on the petiole and veins of older leaves. New leaves ...
A haploid generative cell travels down the tube behind the tube nucleus. The generative cell divides by mitosis to produce two ... The second sperm cell fuses with both central cell nuclei, producing a triploid (3n) cell. The zygote develops into an embryo; ... are the male cells; they are borne in the stamens. The female cells, megaspores, divide to become the egg cell. They are ... Flowers produce two kinds of reproductive cells. Microspores, which divide to become pollen grains, ...
The second reason is that haploid cells of one mating type, upon cell division, often produce cells of the opposite mating type ... "They have no cell nucleus or any other organelles inside their cells."Archaea replicate asexually in a process known as binary ... The cell division cycle includes when chromosomes of daughter cells replicate. Because archea have a singular structure ... Bacterial conjugation is the transfer of genetic material between bacterial cells by direct cell-to-cell contact or by a bridge ...
Nerve fibers are cell processes Nerve fibers are outgrowths of nerve cells. Cell division Nerve cells are generated by cell ... Nucleus is key The nucleus is the trophic center for the cell. If the cell is divided only the portion containing the nucleus ... Neurons are cells These individual units are cells as understood from other tissues in the body. Specialization These units may ... This is true of other examples such as connections between horizontal cells of the retina, or the Mauthner cell synapse in ...
The protein relays signals from outside the cell to the cell's nucleus. These signals instruct the cell to grow and divide ( ... who received a single infusion of her blood with engineered T cells with 2 genes encoding T cell receptors, directed to both ... When the protein is bound to GDP, it does not relay signals to the nucleus. The gene product of KRAS, the K-Ras protein, was ... There are two protein products of the KRAS gene in mammalian cells that result from the use of alternative exon 4 (exon 4A and ...
The nuclei lie around the periphery of the cell. Dinospore movement is via flagellar locomotion. In the forms rich with starch ... The second form consists of Coccidinium multiplying rapidly inside the host, however the nucleus does not undergo division ... They will surround themselves with a thin cystic membrane before undergoing division, but will not exceed 16 or 32 nuclei. In C ... Sporocyte nuclei are large and spherical, with around 4-5 chromosomes in total in a general V-shape, which is typical for ...
Lamin is a type of structural protein in the cell nucleus. Lamin may also refer to: Lamin (given name) Lamin (surname) Lamin, ... North Bank Division, Gambia Lamin, Western Division, Gambia Lamin House, in Indonesia This disambiguation page lists articles ...
Cells divide asexually by binary fission. The division process begins as the single nucleus with condensed chromosomes ... The cells also only contain one nucleus with condensed chromosomes in the hypocone. Coolia has an asexual and a sexual life ... The cyst further develops to contain a single nucleus that makes up much of the volume of the cell. At the end of the process, ... The life cycle of Coolia involves an asexual stage where the cell divides by binary fission and a sexual stage where cysts are ...
The cells are bacteria and thus have no nucleus nor internal membrane system. To multiply, they form two new cells when they ... divide by binary fission. Along the trichomes, larger specialist nitrogen-fixing cells called heterocysts occur between the ... Inside the thin sheath are numerous unbranched hair-like structures called trichomes formed of short cells in a string. ... ordinary cells. When wet, Nostoc commune is bluish-green, olive green or brown but in dry conditions it becomes an ...
Every neuron has a nucleus, which is the trophic center of the cell (The part which must have access to nutrition). If the cell ... Neurons are generated by cell division. Neurons are connected by sites of contact and not via cytoplasmic continuity. (A cell ... The cell is the basic unit of structure, function, and organization in all organisms. All cells come from preexisting, living ... Nerve fibers are the result of cell processes and the outgrowths of nerve cells. (Several axons are bound together to form one ...
In dividing cells, AAV DNA is lost through cell division, since the episomal DNA is not replicated along with the host cell DNA ... AAV-based gene therapy vectors form episomal concatemers in the host cell nucleus. In non-dividing cells, these concatemers ... Replication of the virus can also vary in one cell type, depending on the cell's current cell cycle phase. The characteristic ... It can also infect non-dividing cells and has the ability to stably integrate into the host cell genome at a specific site ( ...
When nutrients are provided uniformly, the nuclei in the plasmodium divide synchronously, accounting for the interest in using ... a large single cell with multiple nuclei. While nutrients are available, the network-shaped plasmodium can grow to a foot or ... and the cell cycle. The two vegetative cell types, amoebae and plasmodia, differ markedly in morphology, physiology and ... P. polycephalum as a model organism to study the cell cycle, or more specifically the nuclear division cycle. When the ...
Anucleated cells can also arise from flawed cell division in which one daughter lacks a nucleus and the other has two nuclei. ... Eukaryotic cells usually have a single nucleus, but a few cell types, such as mammalian red blood cells, have no nuclei, and a ... "The Nucleus". MBInfo. "Learn about the Cell Nucleus". cellnucleus.com. Website covering structure and function of the nucleus ... having already described cells multiplying by division and believing that many cells would have no nuclei. The idea that cells ...
It explains the success of all cells with a nucleus. ... The protein complex that enables cells with a nucleus to divide ... Cell division in cells with a nucleus: microtubules (red) are pulling the chromosomes (blue) towards both sides of the nucleus ... System that controls cell division resembles a mosaic. Protein complex in cell nucleus developed from primal proteins. 28 May ... coordinated division is essential to a cells success. To me, the kinetochore is the black hole of eukaryotic cell division. We ...
No one knows exactly how the nucleus evolved and created that division. Growing evidence has persuaded some researchers, ... New theory suggests that giant viruses created the cell nucleus. Denyse OLeary. December 6, 2020. Cell biology, Intelligent ... One is that cells "learned" how to construct a nucleus from the giant viruses. If so, they are smarter than we think-or ... A crucial difference, though, is that the partner responsible for the nucleus might not have been a cell at all, but a virus. ...
Cell Cycle Proteins / metabolism* * Cell Division * Cell Nucleus / metabolism * Chromatin / metabolism* * Cytoplasm / ... Here we report that both AtASF1A and AtASF1B proteins bind histone H3, and are localized in the cytoplasm and the nucleus. Loss ... The Atasf1ab mutant plants exhibit cell number reduction, S-phase delay/arrest, and reduced polyploidy levels. Selective up- ... Arabidopsis homologues of the histone chaperone ASF1 are crucial for chromatin replication and cell proliferation in plant ...
Analysis of the mcd1 mutant and cell cycle-dependent expression pattern of Mcd1p s … ... Cell Cycle Proteins / genetics * Cell Cycle Proteins / physiology* * Cell Division * Cell Nucleus / chemistry ... Analysis of the mcd1 mutant and cell cycle-dependent expression pattern of Mcd1p suggest that this protein functions in ...
But viral vectors are risky--they can enter the nucleus during cell division and disrupt genes. Thomas Wagner, a distinguished ... The infected cells produce TK, which kills them when the patient takes the anti-herpes drug ganciclovir. ... But viral vectors are risky--they can enter the nucleus during cell division and disrupt genes. Thomas Wagner, a distinguished ... But viral vectors are risky--they can enter the nucleus during cell division and disrupt genes. Thomas Wagner, a distinguished ...
Our results unveil a novel player in the complex regulation of OPC biology, on the one hand showing that JNK1 ablation cell- ... myelino-genesis are finely regulated by the interplay of cell-intrinsic and extrinsic factors. A variety of extrinsic cues ... arise from highly ramified and proliferative precursors called oligodendrocyte progenitor cells (OPCs). OPC architecture, ... Ki67+ proliferating cells (green) are indicated by white arrows. DAPI (blue) counterstains cell nuclei. (B) Quantification of ...
Cells with an altered Werner protein may divide more slowly or stop dividing earlier than normal, causing growth problems. Also ... Research suggests that this shortened protein is not transported to the cells nucleus. , where it normally interacts with DNA ... in preparation for cell division. . Mutations in the WRN gene often lead to the production of an abnormally short, ... which means both copies of the WRN gene in each cell have mutations. The parents of an individual with Werner syndrome each ...
... producing two identical nuclei in preparation for cell division. Mitosis is generally followed by equal division of the cells ... Somatic Cells. Somatic cells are the cells in the body other than sperm and egg cells (which are called germ cells). In humans ... Chromosomes are microscopic structures containing DNA that reside within the nucleus of a cell. During cell division, these ... Certain epigenetic modifications may be passed on from parent cell to daughter cell during cell division or from one generation ...
Encyclopedia entry about Nucleus, a structure occurring in almost every cell... ... The division of the protoplasm in cell division is generally preceded by that of the nucleus, and it has been observed that, ... The nucleus plays an important part in the division of the cells in their multiplication. There are certain bodies resembling ... Nucleus. Nucleus, a structure occurring in almost every cell (q.v.), whether animal or vegetable, and now recognised as of the ...
Genetic Foundations of Development • Genes and chromosomes • Mitosis:Cell nucleus duplicates • Meiosis: cell division forms ... Nucleus (center of cell) contains chromosomes and genes Gene: a segment of DNA (spiraled double chain) containing the ... Genetic Foundations of Development • The collaborative gene • Nucleus of a human cell: • Chromosomes:Thread-like structures • ... Sickle-cell anemia - red blood cells affected • Cystic fibrosis, diabetes, hemophilia, spina bifida, Tay-sachs and Huntington ...
... leaving a single nucleus in both cells. Subsequently, the conjugating ciliates pull apart and their zygotic nuclei divide ... repeatedly to create both types of nuclei. This development is often immediately followed by the creation of new cells via ... two different types of nuclei, and filamentous trichocysts, which may be involved in defense or extended for anchoring purposes ...
Chromosomes, distinct structures made up of DNA and protein, are located in the nucleus of each cell. Because chromosomes are ... Chromosomal abnormalities typically occur due to a problem with cell division.. For example, Down syndrome (sometimes referred ... Basal Cell Nevus Syndrome Picture. Nevoid basal cell carcinoma syndrome affects many areas of the body and means you have an ... High Red Blood Cell Count (Polycythemia). Polycythemia (elevated red blood cell count) is a rare blood disease in which the ...
Subcellular location: Nucleus, Cell membrane. Synonyms: PPP1R81, Repo-Man, Cell division cycle-associated protein 2, Recruits ... CDCA2 (Cell Division Cycle Associated 2 (CDCA2)) Bindungsspezifität Alle Epitope für CDCA2 Antikörper * AA 361-450 14 ... anti-Cell Division Cycle Associated 2 (CDCA2) (C-Term) antibody CDCA2 Reaktivität: Human WB, ELISA Wirt: Kaninchen Polyclonal ... anti-Cell Division Cycle Associated 2 (CDCA2) (AA 724-1023) antibody CDCA2 Reaktivität: Human WB Wirt: Kaninchen Polyclonal ...
2.3.1.1.5. Telophase: Nucleus forms (ends as daughter cells), chromosomes decondense ... Cell Division. 2.3.1. Mitosis - Somatic (body) cells. 2.3.1.1. Stages:. 2.3.1.1.1. Interphase: where DNA gets photocopied ( ... 2.2.1. Enzymes (protein) break up the DNA cell and helps form identical DNA cells ... 2.3.2.2.4. Telophase II: Haploid daughter cells forming. 2.3.2.2.5. Sister chromatids finally separate; four haploid daughter ...
This ability to enter the nucleus is specific of lentiviruses, other retroviruses cannot and rely on cell division to access ... In the second step, the PIC enters cell nucleus. This process is mediated through integrase and Vpr proteins, and allows the ... The second function is to play a role in nuclear localization of the viral genome at the very start of cell infection. Matrix ... This enzyme activity takes place after virion entry into a cell and reverse transcription of the RNA genome in dsDNA. The first ...
When the ovum is shed the nucleus is in the final stages of meiosis (cell division). It is surrounded by few layers of follicle ... until there is a solid ball of cells. This is called a morula. As division continues a hollow ball of cells develops. This is a ... Division continues to form a hollow ball of cells called the blastocyst. This is the stage that implants in the uterus. ... After fertilization in the fallopian tube the zygote divides over and over by mitosis to become a ball of cells called a morula ...
This ability to enter the nucleus is specific of lentiviruses, other retroviruses cannot and rely on cell division to access ... In the second step, the PIC enters cell nucleus. This process is mediated through integrase and Vpr proteins, and allows the ... The second function is to play a role in nuclear localization of the viral genome at the very start of cell infection. Matrix ... This enzyme activity takes place after virion entry into a cell and reverse transcription of the RNA genome in dsDNA. The first ...
Asbestos fiber penetrating the cell or cell nucleus may exercise modes of direct genetic or epigenetic damage. In our above ... involved in chromosomal separation during cell division. During mitosis, the nuclear membrane disintegrates, possibly providing ... release of ROS from inflammatory cells and not target cells. However, asbestos fiber can generate ROS spontaneously in cell- ... Similar effects were seen for multi-nuclei induction and for dye-exclusion viability measure for cell toxicity. No activity was ...
... and fails to complement cell survival following exposure to PARP inhibitors and crosslinking drugs. Surprisingly, despite ... and fails to complement cell survival following exposure to PARP inhibitors and crosslinking drugs. Surprisingly, despite ... Micronuclei contain chromosomes, or damaged chromosome fragments, not incorporated into the nucleus during cell division and ... Stable cell clones generated from DLD-1 BRCA2−/− cells were grown on coverslips at 105 cells/well in a 24-well plate for 24 h. ...
Our cells nucleus contains two meters of DNA that must be propagated without error each time a cell divides. When cells go ... When cells divide, the DNA becomes packed as tightly organised X-shaped chromosomes that are then evenly distributed to the two ... "It is exciting to finally understand at a molecular and atomic level how the iconic X-shape of chromosomes during cell division ... scientists have puzzled over how chromosomes receive their X-shape during cell division. ...
5. Nature of Cells. *6. Cell Membrane and Nucleus. *7. Movement through Cell Membranes ... 8. Cell Organelles. *9. Cell Division. *10. Ecosystems. *11. Biomes. *12. Energy Capture - Photosynthesis ... Masters Class High School Biology Set brings Gods creation of cells, ecosystems, biomes, the genetic code, and more to life ... Explore the fundamental concepts of cell biology and important recent developments. *Study the development of classical ...
meiosis, division of a germ cell involving two fissions of the nucleus and giving rise to four gametes, or sex...... ... messenger RNA (mRNA), molecule in cells that carries codes from the DNA in the nucleus to the sites of protein...... ... metaphase, in mitosis and meiosis, the stage of cell division characterized by the alignment of the chromosomes...... ... mitosis, a process of cell duplication, or reproduction, during which one cell gives rise to two genetically identical...... ...
Nucleus or cell containing one copy of each chromosome.. Meiosis. -Division of the cells nucleus in which the number of ... The physical division of the cytoplasm of a eukaryotic cell to form two daughter cells, each housing a newly formed nuclei. ... Nucleus or cell containing two copies of each chromosome generated by fusion of two haploid nuclei. ...
... the strands of DNA stored in the nucleus of cells. The telomeres shorten each time a cell divides to make new cells, until they ... reach a critical short length and the cells enter an inactive state and then die. Therefore telomeres shorten as an individual ...
They have their own DNA, which is separate from the DNA found in the nucleus of the cell. And both organelles use their DNA to ... The two organelles also reproduce like bacteria, replicating their own DNA and directing their own division. ... Some of the oldest cells on Earth are single-cell organisms called bacteria. Fossil records indicate that mounds of bacteria ... Yet the earliest cells originated in this extreme environment. Today, a group of single-celled organisms called archaeabacteria ...
... without forming a cell wall between each nucleus. After about eight rounds of cell division, about 256 nuclei occupy a large ... Guard cells. The stoma is bounded by two guard cells. The guard cells differ from the epidermal cells in the following aspects ... The epidermal tissue includes several differentiated cell types: epidermal cells, guard cells, subsidiary cells, and epidermal ... Parenchyma cells are capable of cell division even after maturation (i.e. they are still meristematic). They have thin, but ...
... the module details each phase of this cell process. It provides an overview of the structure of cell components that are ... mitosis and cancer is explored as is the mechanism by which anti-cancer drugs work to slow down or prevent cell division. ... division of the eukaryotic. cell nucleus. that occurs just prior to cytokinesis. , which is the division of the cell itself. So ... You can learn about interphase in detail in our Cell Division I: The Cell Cycle module.) A representation of cell cycle phases ...
Cells under a microscope. Stem cell research. Cell therapy. Cell division. 3d illustration ... Transparent cell stem background template. Biology research dna nucleus cells vector pattern. ... Cancer cell. Oncology, research, structure. mutation, somatic cell of the body. genetic predisposition. Neoplasms, cancerous ... Labeled educational division with provisioning, regulating, cultural and supporting planet save regulation vector illustration ...

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