TAILIEUCHUNG - Design principles of biological circuits and introduction to systems biology: Part 2

(BQ) Continued part 1, part 2 of the document Design principles of biological circuits and introduction to systems biology has contents: Robust patterning in development, kinetic proofreading, optimal gene circuit design, demand rules for gene regulation, graph properties of transcription networks,. and other contents. | Design principles of biological circuits and introduction to systems biology: Part 2 Chapter 8 Robust Patterning in Development INTrOduCTION Development is the remarkable process in which a single cell, an egg, becomes a multicel- lular organism. During development, the egg divides many times to form the cells of the embryo. All of these cells have the same genome. If they all expressed the same proteins, the adult would be a shapeless mass of identical cells. During development, therefore, the progeny of the egg cell must assume different fates in a spatially organized manner to become the various tissues of the organism. The difference between cells in different tis- sues lies in which proteins they express. In this chapter, we will consider how these spatial patterns can be formed precisely. To form a spatial pattern requires positional information. This information is carried by gradients of signaling molecules (usually proteins) called morphogens. How are mor- phogen gradients formed? In the simplest case, the morphogen is produced at a certain source position and diffuses into the region that is to be patterned, called the field. A con- centration profile is formed, in which the concentration of the morphogen is high near the source and decays with distance from the source. The cells in the field are initially all identical and can sense the morphogen by means of receptors on the cell surface. Mor- phogen binds the receptors, which in turn activate signaling pathways in the cell that lead to expression of a set of genes. Which genes are expressed depends on the concentration of morphogen. The fate of a cell therefore depends on the morphogen concentration at the cell’s position. The prototypical model for morphogen patterning is called the French flag model (Fig- ure ) (Wolpert, 1969; Wolpert et al., 2002). The morphogen concentration M(x) decays with distance from its source at x = 0. Cells that sense an M .

• Y khoa - Dược
• Systems biology design principles
• Biological circuits
• Transcription networks
• Graph properties
• Robust patterning
• Kinetic proofreading
• Pptimal gene circuit design
• Basic concepts
• Signal transduction
• Neuronal Networks