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Cell Division Orientation
Cell division orientation is the direction along which the new daughter cells are formed. Cell division orientation is important for morphogenesis, cell fate and tissue homeostasis. Abnormalities in the cell division orientation leads to the malformations during development and cancerous tissues. Factors that influence cell division orientation are cell shape, anisotropic localization of specific proteins and mechanical tensions. Implication for morphogenesis Cell division orientation is one of the mechanisms that shapes tissue during development and morphogenesis. Along with cell shape changes, cell rearrangements, apoptosis and growth, oriented cell division modifies the geometry and topology of live tissue in order to create new organs and shape the organisms. Reproducible patterns of oriented cell divisions were described during morphogenesis of ''Drosophila'' embryos, ''Arabidopsis thaliana'' embryos, ''Drosophila'' pupa, zebrafish embryos and mouse early embryos. Oriented c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell (biology)
The cell is the basic structural and functional unit of life forms. Every cell consists of a cytoplasm enclosed within a membrane, and contains many biomolecules such as proteins, DNA and RNA, as well as many small molecules of nutrients and metabolites.Cell Movements and the Shaping of the Vertebrate Body in Chapter 21 of Molecular Biology of the Cell '' fourth edition, edited by Bruce Alberts (2002) published by Garland Science. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos. It is also common to describe small molecules such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morphogenesis
Morphogenesis (from the Greek ''morphê'' shape and ''genesis'' creation, literally "the generation of form") is the biological process that causes a cell, tissue or organism to develop its shape. It is one of three fundamental aspects of developmental biology along with the control of tissue growth and patterning of cellular differentiation. The process controls the organized spatial distribution of cells during the embryonic development of an organism. Morphogenesis can take place also in a mature organism, such as in the normal maintenance of tissue by stem cells or in regeneration of tissues after damage. Cancer is an example of highly abnormal and pathological tissue morphogenesis. Morphogenesis also describes the development of unicellular life forms that do not have an embryonic stage in their life cycle. Morphogenesis is essential for the evolution of new forms. Morphogenesis is a mechanical process involving forces that generate mechanical stress, strain, and moveme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Fate
Within the field of developmental biology, one goal is to understand how a particular cell develops into a final cell type, known as fate determination. Within an embryo, several processes play out at the cellular and tissue level to create an organism. These processes include cell proliferation, differentiation, cellular movement and programmed cell death. Each cell in an embryo receives molecular signals from neighboring cells in the form of proteins, RNAs and even surface interactions. Almost all animals undergo a similar sequence of events during very early development, a conserved process known as embryogenesis. During embryogenesis, cells exist in three germ layers, and undergo gastrulation. While embryogenesis has been studied for more than a century, it was only recently (the past 25 years or so) that scientists discovered that a basic set of the same proteins and mRNAs are involved in embryogenesis. Evolutionary conservation is one of the reasons that model systems such as t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TCJ Orients Spindle Apparatus During Cell Division
TCJ may refer to: *Eiken (studio) *The Comics Journal *TCJ subsection at Cell junction Cell junctions (or intercellular bridges) are a class of cellular structures consisting of multiprotein complexes that provide contact or adhesion between neighboring cells or between a cell and the extracellular matrix in animals. They also main ... *Tube CAD Journal (Online Publication) *Tree Climbing Japan (Outdoor activity) {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oskar Hertwig
Oscar Hertwig (21 April 1849 in Friedberg – 25 October 1922 in Berlin) was a German embryologist and zoologist known for his research in developmental biology and evolution. Hertwig is credited as the first man to observe sexual reproduction by looking at the cells of sea urchins under the microscope. Biography Hertwig was the elder brother of zoologist-professor Richard Hertwig (1850–1937). The Hertwig brothers were the most eminent scholars of Ernst Haeckel (and Carl Gegenbaur) from the University of Jena. They were independent of Haeckel's philosophical speculations but took his ideas in a positive way to widen their concepts in zoology. Initially, between 1879 and 1883, they performed embryological studies, especially on the theory of the coelom (1881), the fluid-filled body cavity. These problems were based on the phylogenetic theorems of Haeckel, i.e. the biogenic theory (German = biogenetisches Grundgesetz), and the "gastraea theory". Within 10 years, the two broth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hertwig Rule
Hertwig's rule, or the long axis rule states that a cell divides along its long axis. Introduced by the German zoologist Oscar Hertwig in 1884, the rule emphasizes the cell shape as a default mechanism of spindle apparatus orientation. Hertwig's rule predicts cell division orientation, which is important for tissue architecture, cell fate and morphogenesis. Discovery Hertwig's experiments studied the orientation of frog egg divisions. The frog egg has a round shape and the first division occurs in a random orientation. Hertwig compressed the egg between two parallel plates. The compression forced the egg to change its shape from round to elongated. Hertwig noticed that elongated egg divides not randomly, but orthogonally to its long axis. The new daughter cells were formed along the longest axis of the cell. This observation thus became known as 'Hertwig's rule' or 'long axis rule'. Confirmation and mechanism Recent studies in animal and plant systems support the 'long axis rule' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Junction
Cell junctions (or intercellular bridges) are a class of cellular structures consisting of multiprotein complexes that provide contact or adhesion between neighboring cells or between a cell and the extracellular matrix in animals. They also maintain the paracellular barrier of epithelia and control paracellular transport. Cell junctions are especially abundant in epithelial tissues. Combined with cell adhesion molecules and extracellular matrix, cell junctions help hold animal cells together. Cell junctions are also especially important in enabling communication between neighboring cells via specialized protein complexes called communicating (gap) junctions. Cell junctions are also important in reducing stress placed upon cells. In plants, similar communication channels are known as plasmodesmata, and in fungi they are called septal pores. Types In vertebrates, there are three major types of cell junction: *Adherens junctions, desmosomes and hemidesmosomes (anchoring junct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spindle Apparatus
In cell biology, the spindle apparatus refers to the cytoskeletal structure of eukaryotic cells that forms during cell division to separate sister chromatids between daughter cells. It is referred to as the mitotic spindle during mitosis, a process that produces genetically identical daughter cells, or the meiotic spindle during meiosis, a process that produces gametes with half the number of chromosomes of the parent cell. Besides chromosomes, the spindle apparatus is composed of hundreds of proteins. Microtubules comprise the most abundant components of the machinery. Spindle structure Attachment of microtubules to chromosomes is mediated by kinetochores, which actively monitor spindle formation and prevent premature anaphase onset. Microtubule polymerization and depolymerization dynamic drive chromosome congression. Depolymerization of microtubules generates tension at kinetochores; bipolar attachment of sister kinetochores to microtubules emanating from opposite cell pol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Biology
Cell biology (also cellular biology or cytology) is a branch of biology that studies the structure, function, and behavior of cells. All living organisms are made of cells. A cell is the basic unit of life that is responsible for the living and functioning of organisms. Cell biology is the study of structural and functional units of cells. Cell biology encompasses both prokaryotic and eukaryotic cells and has many subtopics which may include the study of cell metabolism, cell communication, cell cycle, biochemistry, and cell composition. The study of cells is performed using several microscopy techniques, cell culture, and cell fractionation. These have allowed for and are currently being used for discoveries and research pertaining to how cells function, ultimately giving insight into understanding larger organisms. Knowing the components of cells and how cells work is fundamental to all biological sciences while also being essential for research in biomedical fields such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Anatomy
Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Locations * Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery with only a few monks or nuns * Prison cell, a room used to hold people in prisons Groups of people * Cell, a group of people in a cell group, a form of Christian church organization * Cell, a unit of a clandestine cell system, a penetration-resistant form of a secret or outlawed organization * Cellular organizational structure, such as in business management Science, mathematics, and technology Computing and telecommunications * Cell (EDA), a term used in an electronic circuit design schematics * Cell (microprocessor), a microprocessor architecture developed by Sony, Toshiba, and IBM * Memory cell (computing), the basic unit of (volatile or non-volatile) computer memory * Cell, a unit in a database table or spreadsheet, formed by the i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Cycle
The cell cycle, or cell-division cycle, is the series of events that take place in a cell that cause it to divide into two daughter cells. These events include the duplication of its DNA (DNA replication) and some of its organelles, and subsequently the partitioning of its cytoplasm, chromosomes and other components into two daughter cells in a process called cell division. In cells with nuclei ( eukaryotes, i.e., animal, plant, fungal, and protist cells), the cell cycle is divided into two main stages: interphase and the mitotic (M) phase (including mitosis and cytokinesis). During interphase, the cell grows, accumulating nutrients needed for mitosis, and replicates its DNA and some of its organelles. During the mitotic phase, the replicated chromosomes, organelles, and cytoplasm separate into two new daughter cells. To ensure the proper replication of cellular components and division, there are control mechanisms known as cell cycle checkpoints after each of the key steps ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cellular Processes
The cell is the basic structural and functional unit of life forms. Every cell consists of a cytoplasm enclosed within a membrane, and contains many biomolecules such as proteins, DNA and RNA, as well as many small molecules of nutrients and metabolites.Cell Movements and the Shaping of the Vertebrate Body in Chapter 21 of Molecular Biology of the Cell '' fourth edition, edited by Bruce Alberts (2002) published by Garland Science. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos. It is also common to describe small molecules such as < ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
