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Clonal Expansion And Monoclonal Versus Polyclonal Proliferation
Clonal may refer to: Biology *Clonal interference, a phenomenon that occurs when two (or more) beneficial mutations arise independently in different individuals in a genetically homogeneous population of an asexually reproducing organism * Aggregating anemone, also called clonal anemone *Vegetative cloning, a form of asexual reproduction in plants * Clonal reproduction Immunology *Clonal deletion, a process by which B cells and T cells are deactivated before act significantly upon specific antigens *Clonal selection theory, a model for how the immune system responds to infection *Clonal anergy, a lack of reaction by the body's defense mechanisms to foreign substance See also * Clone (other) *Clonalis House *Clone (genetics) *Cloning Cloning is the process of producing individual organisms with identical or virtually identical DNA, either by natural or artificial means. In nature, some organisms produce clones through asexual reproduction. In the field of biotechno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clonal Interference
Clonal interference is a phenomenon in evolutionary biology, related to the population genetics of organisms with significant linkage disequilibrium, especially Asexual reproduction, asexually reproducing organisms. The idea of clonal interference was introduced by American geneticist Hermann Joseph Muller in 1932. It explains why beneficial mutations can take a long time to get fixated or even disappear in asexually reproducing populations. As the name suggests, clonal interference occurs in an asexual lineage ("clone") with a beneficial mutation. This mutation would be likely to get fixed if it occurred alone, but it may fail to be fixed, or even be lost, if another beneficial-mutation lineage arises in the same population; the multiple clones interfere with each other. Mechanism of clonal interference Whenever a beneficial mutation arises in a population, for example mutation A, the carrier of the mutation obtains a higher fitness compared to members of the population without ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aggregating Anemone
The aggregating anemone (''Anthopleura elegantissima''), or clonal anemone, is the most abundant species of sea anemone found on rocky, tide swept shores along the Pacific coast of North America. This cnidarian hosts endosymbiotic algae called zooxanthellae that contribute substantially to primary productivity in the intertidal zone. The aggregating anemone has become a model organism for the study of temperate cnidarian-algal symbioses. Description The polyps of the aggregating anemone reach up to eight cm across the oral disk with approximately 100 tentacles in three or four rows around the margins of the oral disk. Most are olive to bright green (depending on the species of algal symbionts present) with tentacles tipped in pink. Individuals that live in microhabitats that are deficient in photosynthetically active radiation (PAR), such as under docks or in caves, lack symbionts and are pale yellow to white in color. Range Pacific coast of North America from Alaska, Uni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vegetative Cloning
Vegetative reproduction (also known as vegetative propagation, vegetative multiplication or cloning) is any form of asexual reproduction occurring in plants in which a new plant grows from a fragment or cutting of the parent plant or specialized reproductive structures, which are sometimes called vegetative propagules. Many plants naturally reproduce this way, but it can also be induced artificially. Horticulturists have developed asexual propagation techniques that use vegetative propagules to replicate plants. Success rates and difficulty of propagation vary greatly. Monocotyledons typically lack a vascular cambium, making them more challenging to propagate. Background Plant propagation is the process of plant reproduction of a species or cultivar, and it can be sexual or asexual. It can happen through the use of vegetative parts of the plants, such as leaves, stems, and roots to produce new plants or through growth from specialized vegetative plant parts. While man ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clonal Reproduction
Cloning is the process of producing individual organisms with identical or virtually identical DNA, either by natural or artificial means. In nature, some organisms produce clones through asexual reproduction. In the field of biotechnology, cloning is the process of creating cloned organisms (copies) of Cell (biology), cells and of DNA fragments (molecular cloning). Etymology Coined by Herbert J. Webber, the term clone derives from the Ancient Greek word (), ''twig'', which is the process whereby a new plant is created from a twig. In botany, the term ''lusus'' was used. In horticulture, the spelling ''clon'' was used until the early twentieth century; the final ''e'' came into use to indicate the vowel is a "long o" instead of a "short o". Since the term entered the popular lexicon in a more general context, the spelling ''clone'' has been used exclusively. Natural cloning Cloning is a natural form of reproduction that has allowed life forms to spread for hundreds of millio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clonal Deletion
In immunology, clonal deletion is the removal through apoptosis of B cells and T cells that have expressed receptors for self before developing into fully immunocompetent lymphocytes. This prevents recognition and destruction of self host cells, making it a type of negative selection or central tolerance. Central tolerance prevents B and T lymphocytes from reacting to self. Thus, clonal deletion can help protect individuals against autoimmunity. Clonal deletion is thought to be the most common type of negative selection. It is one method of immune tolerance. Discovery and function Frank Macfarlane Burnet proposed autoreactive cells would be terminated before maturation in order to prevent further proliferation in his study in 1959. There are millions of B and T cells inside the body, both created within the bone marrow and the latter matures in the thymus, hence the T. Each of these lymphocytes express specificity to a particular epitope, or the part of an antigen to which B ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clonal Selection
In immunology, clonal selection theory explains the functions of cells of the immune system (lymphocytes) in response to specific antigens invading the body. The concept was introduced by Australian doctor Frank Macfarlane Burnet in 1957, in an attempt to explain the great diversity of antibodies formed during initiation of the immune response. The theory has become the widely accepted model for how the human immune system responds to infection and how certain types of B and T lymphocytes are selected for destruction of specific antigens. The theory states that in a pre-existing group of lymphocytes (specifically B cells), a specific antigen activates (i.e. selects) only its counter-specific cell, which then induces that particular cell to multiply, producing identical clones for antibody production. This activation occurs in secondary lymphoid organs such as the spleen and the lymph nodes. In short, the theory is an explanation of the mechanism for the generation of diversity o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anergy
In immunology, anergy is a lack of reaction by the body's defense mechanisms to foreign substances, and consists of a direct induction of peripheral lymphocyte tolerance. An individual in a state of anergy often indicates that the immune system is unable to mount a normal immune response against a specific antigen, usually a self-antigen. Lymphocytes are said to be ''anergic'' when they fail to respond to their specific antigen. Anergy is one of three processes that induce tolerance, modifying the immune system to prevent self-destruction (the others being clonal deletion and immunoregulation). Mechanism This phenomenon was first described in B lymphocytes by Gustav Nossal and termed "clonal anergy." The clones of B lymphocytes in this case can still be found alive in the circulation, but are ineffective at mounting immune responses. Later Ronald Schwartz and Marc Jenkins described a similar process operating in the T lymphocyte. Many viruses (HIV being the most extreme examp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clone (other)
Clone or Clones or Cloning or Cloned or The Clone may refer to: Places * Clones, County Fermanagh * Clones, County Monaghan, a town in Ireland Biology * Clone (B-cell), a lymphocyte clone, the massive presence of which may indicate a pathological condition * Clone (cell biology), a group of identical cells that share a common ancestry * Clonal plant, the result of asexual, vegetative reproduction when a new plant grows from a fragment of the parent plant * Cloning, the production of any organism whose genetic information is identical to that of a parent organism from which it was created Computing and technology * Clone (computing), computer hardware or software designed to function in the same way as an original ** Video game clone, a software game or game franchise heavily inspired by another ** ''Clones'' (video game), a video game clone ''Lemmings'' * Clone (Java method), a method in the Java programming language for object duplication * Clone (Linux system call), in C, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clonalis House
Clonalis House (), Castlerea, County Roscommon, Ireland, is the ancestral home of the O'Conor Don, who is a direct descendant Cathal Crobhdearg Ua Conchobair, King of Connacht, a younger brother of the last High King of Ireland, Ruaidrí Ua Conchobair. Clonalis was constructed in 1878 by Charles Owen O'Conor as a replacement for an earlier house on the same site which was frequently damaged by flooding. Built of mass concrete, its design by Frederick Pepys Cockerell is of a mixture of styles drawing on the traditions of Italianate and Queen Anne Style architecture. Its history reflects the turbulence of Irish history having once been occupied by the Irish Republican Army before it was shelled and captured by Free State Forces during the Irish Civil War. Some 100,000 volumes are contained in the family archives and library of the O'Conor Don The O'Conor family (Middle Irish: ''Ó Conchubhair''; Modern ga, Ó Conchúir) are an Irish noble house and were one of the mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clone (genetics)
Molecular cloning is a set of experimental methods in molecular biology that are used to assemble recombinant DNA molecules and to direct their replication within host organisms. The use of the word ''cloning'' refers to the fact that the method involves the replication of one molecule to produce a population of cells with identical DNA molecules. Molecular cloning generally uses DNA sequences from two different organisms: the species that is the source of the DNA to be cloned, and the species that will serve as the living host for replication of the recombinant DNA. Molecular cloning methods are central to many contemporary areas of modern biology and medicine. In a conventional molecular cloning experiment, the DNA to be cloned is obtained from an organism of interest, then treated with enzymes in the test tube to generate smaller DNA fragments. Subsequently, these fragments are then combined with vector DNA to generate recombinant DNA molecules. The recombinant DNA is then in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
