cell biology Chapter 15 paper

cell biology Chapter 15 paper - Christopher Hopper Dr....

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Christopher Hopper Dr. Angela Reiken Cell Biology Chapter 15 The extracellular signal molecule used during development is called a morphogen, it diffuses out from a localized cellular source (a signaling center), generating a signal concentration gradient. The responding cells adopt different cell fates in accordance with their position in the gradient: those cells closest to the signaling center that encounter the highest concentration of the morphogen have the highest number of receptors activated and follow one pathway of development, whereas those slightly further away follow another, and so on. The different levels of receptor activation lead to differences in the concentration or activity of one or more gene regulatory proteins in the nucleus of each cell, which in turn results in different patterns of gene expression. Further, more local signaling interactions between the cells in the gradient often help determine and stabilize the different fate choices. It is normal to believe of signaling systems in terms of the changes produced when an
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This note was uploaded on 04/03/2011 for the course BIO 220 taught by Professor Drjf during the Spring '11 term at Belhaven.

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cell biology Chapter 15 paper - Christopher Hopper Dr....

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