Role of wound epidermis and apical epidermal cap, Biology

Assignment Help:

Role of Wound Epidermis and Apical Epidermal Cap

Earlier described that amputation, the stump epidermal cells at the wound edge migrate over and quickly cover the wound to from a multilayered apical epidermal cap. The formation of this cap depends upon the early innervations of the wound epidermis through nerve fibers. The cap fails to make if the limb is denervated before or immediately after amputation. If this cap is removed regeneration fails to take place. If an additional cap is grafted on the emergent blastema it induces regeneration of supernumerary limb. Thus the apical epidermal cap formed via wound epidermis is necessary for permitting regeneration. Any other epidermis grafted on the wound surface does not make the apical cap and does not support regeneration. This shows that only the apical cap that developed from the wound epithelium could promote and maintain regeneration of the limb.

In the non-regenerating amputated limb-stumps of older tadpoles and adults of frogs, the characteristic apical epidermal cap does not develop and thus regeneration does not take place. Experimental results point out that wound epidermis stimulates dedifferentiation and mitosis in the underlying cells arising from stump tissue so inducing the formation and growth of the blastema and the consequent regeneration of the limb. The blastema cells in the zone instantaneously adjacent to the apical cap remain in an undifferentiated and proliferating state, while those proximal to this zone start to differentiate. In this way proximal distal pattern of re-differentiation of blastema cells is controlled through the epidermal cap. You may recall that the apical ectodermal ridge (AER) of the embryonic limb bud also plays a identical role in allowing distal outgrowth of the limb. Both the AER in, embryonic limb development and apical cap of the regenerating limb stimulate cellular proliferation in cells situated beneath them and keep them from differentiating that enables differentiation of limb tissues in a proximo-distal sequence.


Related Discussions:- Role of wound epidermis and apical epidermal cap

Do all mammals have a placenta, Q. Do all mammals have a placenta? Mamm...

Q. Do all mammals have a placenta? Mammals of the monotreme group (platypus, echidnas) are oviparous egg- laying and they don't have a placenta. Mammals of the marsupial group

Does the environment exert an influence on the phenotype, Does the environm...

Does the environment exert an influence on the phenotype? A phenotype may be changed (compared to the original situation conditioned by its genotype) by nongenetic means. Examp

What is an osteoporosis, In detail , how does the body maintains the blood ...

In detail , how does the body maintains the blood calcium ion homeostasis ( including the description of negative feedback system, organs and hormones involved) What is osteoporosi

Mechanism of cleavage, Mechanism of Cleavage Such as the mitotic divi...

Mechanism of Cleavage Such as the mitotic division in any cell, cleavage is the result of two events: mitotic nuclear division (Karyokinesis) followed via cytoplasmic divisio

Explain the protection of erythrocytes and cell membrane, Explain the Prote...

Explain the Protection of erythrocytes and cell membrane? Protection of erythrocytes: Vitamin E protects erythrocytes from haemolysis by the production of oxidizing agents

O-linked oligosaccharides , Most proteins made by ribosomes on the RER (rou...

Most proteins made by ribosomes on the RER (rough endoplasmic reticulum) are glycoproteins, which is they hold short chains of carbohydrates (oligosaccharides) covalently related t

Explain emtricitabine, Emtricitabine (FTC, Emtriva) Emtricitabine is th...

Emtricitabine (FTC, Emtriva) Emtricitabine is the 5-fluorinated derivative of lamivudine. It has same safetyand efficacy, and can be given once daily. It is available alone or

Imagine an animal that hast he system similar to abo blood, Imagine an anim...

Imagine an animal that has a system similar to ABO blood types in humans. The ABO part is the same. In addition, they have a second independent gene that creates a mimic A protein,

What is the genotype of each parent cat, Long-hair in cats is due to a rece...

Long-hair in cats is due to a recessive long allele, l. Black cats are due to a recessive agouti allele, a. A short-haired tabby cat is crossed to a long-haired tabby cat, and they

Tolrance, geographical range graph on minimum and maximum range of toleranc...

geographical range graph on minimum and maximum range of tolerance

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd