Limb regeneration of ancient books

Because our genes are different, in a narrow sense, regeneration means that after the organs of an organism are damaged, the rest grow structures with the same shape and function as the original ones, such as the tail of a gecko, the limbs of a lizard and the feet of a crab, which can be re-formed after being lost. Sea cucumber can form all internal organs, and every part of lower animals, such as water margin, earthworm and worm, can form a complete individual and so on. But in a broad sense, regeneration is a common phenomenon in life, from molecules, cells to tissues and organs. Therefore, there are many forms of regeneration.

One is physiological regeneration, that is, cell renewal. For example, about 6 million newborn red blood cells replace the same number of dead red blood cells in the human body every second, and the second is restorative regeneration. Scientists also hope that through this discovery, a new method for treating common joint diseases such as osteoarthritis and injury will be developed. The article points out that the key significance of this discovery is that this healing mechanism may be used for joint repair and lay the foundation for limb regeneration.

Before the publication of this study, scientists generally believed that the human body could not repair damaged and degenerated articular cartilage by itself, and organ regeneration of salamanders was a combination of various cell growth and development forms, including cell dedifferentiation, cell migration and cell proliferation, rather than simple supplement or proliferation. After the forelimb of the salamander was removed, the adhesion of cells in the wound weakened, and they moved to the wound through deformation, forming a layer of cells to seal the wound.

This layer of cells is called the apical cap or ectodermal apical cap, and the cells under the apical cap, such as bone cells, chondrocytes, fibroblasts, muscle cells and glial cells, rapidly dedifferentiate to form embryos. After that, the germ was deprived of oxygen, the ph value decreased, and the lysosomal activity increased, which promoted the removal of damaged tissues.

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Today, the explanation why human beings can't have the function of limb regeneration like salamanders is here.