Question

Explain the relevance of patterning, positional information, and signalling pathways in the process of regeneration.

Answer 1

• ​Pattern formation is controlled by genes. The role of genes in pattern formation is an aspect of morphogenesis. The mechanisms involved are well seen in the anterior and posterior patterning of embryos. Patterning describes the mechanism by which initially equivalent cells in a developing tissue in an embryo assume complex forms and functions. The process of embryogenesis involves coordinated cell fate control. Pattern formation is genetically controlled and often involves each cell in a field sensing and responding to its position along a morphogen gradient, followed by short distance cell to cell communication through cell signaling pathwaysto refine the initialpattern.i.e a field of cells is Tyr group of cells whose fates are affected by responding to the same set positional information cues.
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• ​Information necessary to integrate cell activity into a system level patterning program is positional information, enabling cells and tissues to discern their location relative to each other with a complex 3 - dimensional structure. The relevance of this in adult animals is consistent with the dynamic nature of morphostasis, in which shape must be maintained actively throughout life. Positional information plays an important role in patterning behaviour not only of single cells and tissues.
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• ​Receptor activation caused by ligand binding to a receptor is directly coupled to the cells response to the ligand. The entire set of cell changes induced by receptor activation is called a signal transduction pathway. Complex signal transduction pathway involves changes of protein protein interactions inside the cell, induced by an external signal. Many growth factors bind to receptors at the cell surface and simulate cells to progress through the cell cycle and divide. Some signalling transduction pathways respond differently depending upon the amount of signalling received by the cell.​​