Lens regeneration in amphibians, Biology

Lens Regeneration in Amphibians

It is an amazing fact that between all vertebrates only certain amphibians have the unique ability to regenerate lens, iris and retina in adult lire. The amphibians also change in their capability to regenerate a lens and in the source of cells from which a new lens is formed. Members of sub-order salamandridae (salamander, Triturus) have the significant ability of growing a new lens from the dorsal iris epithelium (neural ectoderm).

This is a unique instance of metaplasia, as the regenerating iris is derived from neural ectoderm and may be regarded as an extension of the brain whereas the original lens is derived from the epidermal ectoderm. This kind of regeneration has demonstrated that even adult differentiated cells can keep their potential to produce other cell types. In the larvae of the South African frog. Xenopus laevis an invagination of corneal epithelium gives increment to a ball of cells which transforms into the new lens. The procedure of the new lens regeneration in X. laevis more closely duplicates the embryonic process, like both the first lens and the regenerate lens develop from cells of epidermal ectodermal origin, though, even so it is a case of metaplasia, since differentiated cells of corneal epithelium give rise to lens cells that are morphologically and biochemically very different from those of the corneal epithelium. The regenerating capability in this anuran however species disappears at metamorphosis.

Posted Date: 1/31/2013 4:53:52 AM | Location : United States







Related Discussions:- Lens regeneration in amphibians, Assignment Help, Ask Question on Lens regeneration in amphibians, Get Answer, Expert's Help, Lens regeneration in amphibians Discussions

Write discussion on Lens regeneration in amphibians
Your posts are moderated
Related Questions

Which of the following does NOT contain a guanidinium group Select one: a. Urea b. arginine c. creatine d. guanidinium ion

Q. What does this fungus looks like? Ans. The important characteristic features of aflatoxicosis are jaundice, cirrhosis. Long term exposure to aflatoxins could lead to

What are bacteriophages? Bacteriophages are viruses specialized in parasitism of bacteria. They are used in genetic engineering as molecular cloning vehicles to insert recombin

Which of the following is true for active hyperemia, a local control mechanism within the circulatory system? A. There will be a decrease in force developed by smooth muscles s

Explain the Cardiovascular Effects? You must have heard of the 'French Paradox'. The lower incidence of heart attacks in certain areas of France despite higher prevalence of fa

Question 1 Describe the external features of the heart. Add a note on circulation of blood within the heart Question 2 Discuss the major joints of thorax and pelvis Quest

Ears We have a pair of ears. Each ear has three parts - external, middle and inner ear. The function of the middle ear is transmission of sound waves from external to inner ear

what''s you''re name

Elaborate Evolution by Natural Selection ? The conelaboratecept of natural selection lies at the heart of Darwin's Theory of Evolution. Darwin understood that plants and animal