Morphogenesis 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.
A Belousov–Zhabotinsky reaction, or BZ reaction, is one of a class of reactions that serve as a classical example of non-equilibrium thermodynamics, resulting in the establishment of a nonlinear chemical oscillator. The only common element in these oscillators is the inclusion of bromine and an acid. The reactions are important to theoretical chemistry in that they show that chemical reactions do not have to be dominated by equilibrium thermodynamic behavior. These reactions are far from equilibrium and remain so for a significant length of time and evolve chaotically. In this sense, they provide an interesting chemical model of nonequilibrium biological phenomena; as such, mathematical models and simulations of the BZ reactions themselves are of theoretical interest, showing phenomenon as noise-induced order.
A generegulatory network (GRN) is a collection of molecular regulators that interact with each other and with other substances in the cell to govern the gene expression levels of mRNA and proteins which, in turn, determine the function of the cell. GRN also play a central role in morphogenesis, the creation of body structures, which in turn is central to evolutionary developmental biology (evo-devo).
Mathematical and theoretical biology, or biomathematics, is a branch of biology which employs theoretical analysis, mathematical models and abstractions of living organisms to investigate the principles that govern the structure, development and behavior of the systems, as opposed to experimental biology which deals with the conduction of experiments to test scientific theories. The field is sometimes called mathematical biology or biomathematics to stress the mathematical side, or theoretical biology to stress the biological side. Theoretical biology focuses more on the development of theoretical principles for biology while mathematical biology focuses on the use of mathematical tools to study biological systems, even though the two terms are sometimes interchanged.
A morphogen is a substance whose non-uniform distribution governs the pattern of tissue development in the process of morphogenesis or pattern formation, one of the core processes of developmental biology, establishing positions of the various specialized cell types within a tissue. More specifically, a morphogen is a signaling molecule that acts directly on cells to produce specific cellular responses depending on its local concentration.
Stuart Alan Newman is a professor of cell biology and anatomy at New York Medical College in Valhalla, NY, United States. His research centers around three program areas: cellular and molecular mechanisms of vertebrate limb development, physical mechanisms of morphogenesis, and mechanisms of morphological evolution. He also writes about social and cultural aspects of biological research and technology.
The science of pattern formation deals with the visible, (statistically) orderly outcomes of self-organization and the common principles behind similar patterns in nature.
Decapentaplegic (Dpp) is a key morphogen involved in the development of the fruit fly Drosophila melanogaster and is the first validated secreted morphogen. It is known to be necessary for the correct patterning and development of the early Drosophila embryo and the fifteen imaginal discs, which are tissues that will become limbs and other organs and structures in the adult fly. It has also been suggested that Dpp plays a role in regulating the growth and size of tissues. Flies with mutations in decapentaplegic fail to form these structures correctly, hence the name. Dpp is the Drosophila homolog of the vertebrate bone morphogenetic proteins (BMPs), which are members of the TGF-β superfamily, a class of proteins that are often associated with their own specific signaling pathway. Studies of Dpp in Drosophila have led to greater understanding of the function and importance of their homologs in vertebrates like humans.
Limb development in vertebrates is an area of active research in both developmental and evolutionary biology, with much of the latter work focused on the transition from fin to limb.
Reaction–diffusion systems are mathematical models which correspond to several physical phenomena. The most common is the change in space and time of the concentration of one or more chemical substances: local chemical reactions in which the substances are transformed into each other, and diffusion which causes the substances to spread out over a surface in space.
An eyespot is an eye-like marking. They are found in butterflies, reptiles, cats, birds and fish.
The French flag model is a conceptual definition of a morphogen, described by Lewis Wolpert in the 1960s. A morphogen is defined as a signaling molecule that acts directly on cells to produce specific cellular responses dependent on morphogen concentration. During early development, morphogen gradients generate different cell types in distinct spatial order. French flag patterning is often found in combination with others: vertebrate limb development is one of the many phenotypes exhibiting French flag patterning overlapped with a complementary pattern.
Mathematical Biology is a two-part monograph on mathematical biology first published in 1989 by the applied mathematician James D. Murray. It is considered to be a classic in the field and sweeping in scope.
"The Chemical Basis of Morphogenesis" is an article that the English mathematician Alan Turing wrote in 1952. It describes how patterns in nature, such as stripes and spirals, can arise naturally from a homogeneous, uniform state. The theory, which can be called a reaction–diffusion theory of morphogenesis, has become a basic model in theoretical biology. Such patterns have come to be known as Turing patterns. For example, it has been postulated that the protein VEGFC can form Turing patterns to govern the formation of lymphatic vessels in the zebrafish embryo.
Cell polarity refers to spatial differences in shape, structure, and function within a cell. Almost all cell types exhibit some form of polarity, which enables them to carry out specialized functions. Classical examples of polarized cells are described below, including epithelial cells with apical-basal polarity, neurons in which signals propagate in one direction from dendrites to axons, and migrating cells. Furthermore, cell polarity is important during many types of asymmetric cell division to set up functional asymmetries between daughter cells.
Lee Aaron Segel was an applied mathematician primarily at the Rensselaer Polytechnic Institute and the Weizmann Institute of Science. He is particularly known for his work in the spontaneous appearance of order in convection, slime molds and chemotaxis.
Homeotic protein bicoid is encoded by the bcd maternal effect gene in Drosophilia. Homeotic protein bicoid concentration gradient patterns the anterior-posterior (A-P) axis during Drosophila embryogenesis. Bicoid was the first protein demonstrated to act as a morphogen. Although bicoid is important for the development of Drosophila and other higher dipterans, it is absent from most other insects, where its role is accomplished by other genes.
Cheng-Ming Chuong is a Taiwanese-American biomedical scientist.
Thomas Lecuit, born 4 October 1971 in Saumur, is a French biologist specializing in the emergence of forms or morphogenesis. He is a professor at the Collège de France, holding the Dynamics of Life Chair. He leads a research team at the Institut de Biologie du Développement de Marseille (IBDM), and the Turing Centre for Living Systems, an interdisciplinary centre dedicated to the study of living organisms.
Diffusive–thermal instability or thermo–diffusive instability is an intrinsic flame instability that occurs both in premixed flames and in diffusion flames and arises because of the difference in the diffusion coefficient values for the fuel and heat transport, characterized by non-unity values of Lewis numbers. The instability mechanism that arises here is the same as in Turing instability explaining chemical morphogenesis, although the mechanism was first discovered in the context of combustion by Yakov Zeldovich in 1944 to explain the cellular structures appearing in lean hydrogen flames. Quantitative stability theory for premixed flames were developed by Gregory Sivashinsky (1977), Guy Joulin and Paul Clavin (1979) and for diffusion flames by Jong S. Kim and Forman A. Williams (1996,1997).
