What is morphogenesis

See more words from the same year. Accessed 26 Oct. More Definitions for morphogenesis. Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free! Log in Sign Up. Save Word. Definition of morphogenesis. Examples of morphogenesis in a Sentence Recent Examples on the Web Researchers disagree about the role that bioelectricity plays in morphogenesis.

First Known Use of morphogenesis circa , in the meaning defined above. These asymmetries are generally triggered by genetic instructions carried out by proteins or other chemical and spatial elements. Cell growth is another important aspect of developmental biology that contributes to morphogenesis. Cell growth describes how much a cell grows in terms of its organelle and cytoplasm content. Some cells grow quite large while others remain rather small. Different cell sizes play an important part in morphogenesis, as cells of different sizes can combine in a variety of ways to produce organs with different shapes.

Paul Weiss used a sculptor analogy to describe morphogenesis in his book Principles of Development. He distinguished morphogenesis from growth and explained that growth was the creation of mass whereas morphogenesis was the shaping of that mass. This process of morphogenesis was exemplified by amphibian gastrulation , which had been meticulously described by Johannes Holtfreter and also by asexual reproduction in Volvox. Together, they suggested that these two interpretations offered an excellent theoretical framework to think about development, particularly problems of morphogenesis.

As evidence about the processes of morphogenesis accumulated additional concepts were created. For example, morphogenetic field and morphogenetic substratum were terms used by Joseph Needham in his embryological text Biochemistry and Morphogenesis Needham defined morphogenesis as the process by which an organism acquired its characteristic form.

In John Tyler Bonner published Morphogenesis: An Essay on Development wherein he surveyed a diverse selection of developmental phenomena across a wide range of organisms to determine if he could find shared processes. Development was described as being composed of both constructive and limiting forces; those that built up the organism and those that kept it in check. Bonner identified the constructive processes as growth, differentiation , and morphogenetic movements—those processes that involved cellular movement.

Bonner, like Weiss, described them as analogous to the process of a sculptor shaping clay. Examples include neural crest cells, primordial germ cells, and somite derivatives, and this area has attracted considerable interest. The direction of cell movement within an embryo is controlled by tracks see contact guidance and haptotaxis Table 1 , signaling gradients chemotaxis or boundary interactions.

The key problems in analyzing cell migration in vivo are identifying which cells start to move, the signals for initiating movement, the nature of the migration pathways and the mode of stopping.

Epithelia sheets form bounding surfaces e. Endothelia form the tubes of the vascular system, and are anatomically similar to epithelia but use different adhesion and matrix molecules. The most important mophogenetic processes of epithelia and endothelia are folding, movement e. Drosophila limb and sea-urchin gut extension. Many mesenchymal cells are primitive and will undergo one or more morphogenetic processes e. Later morphogenesis builds on this scaffold. Most functional tissues are of course complex 3D structures composed of both mesenchymal and epithelial cells and their derivatives, together with nervous and vascular tissue.

The morphogenetic processes that lead to their final structures are rich and complex, and not well understood. The first major approach to investigating morphogenesis was to look at the intrinsic morphogenetic properties of cells: Townes and Holtfreter - a classic showed that randomized aggregates of cells from a mix of amphibian embryonic tissues would not only sort themselves out into their cell types but also generate some structure.

The paper demonstrated that the cells themselves had morphogenetic properties that they could use, and stimulated a great deal of work in the '60 '70s and '80s on the morphogenetic abilities of cells. A second approach was to analyze cell behaviour in tissues that that will develop in culture where they can be experimentally manipulated.

As chick and amphibian embryos are relatively large and accessible, they have been the model species of choice for studying morphogenesis e.