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
Explain Cardiac disease Cardiac conduction abnormalities associated with Lyme disease are generally self-limited. Patients with minor cardiac involvement (first-degree atrioven

Hydrarch - Kinds of Succession When succession takes place in a wet area, that is, succession progresses from hydric to mesic conditions. This can be further subdivided as:

What is photoperiodism? Photoperiodism is the biological response shown by some living beings to their daily time of light exposure (photoperiod).

Phylum Chordata- Chordata name given by Balfour. Herst put hemichordata into separate phylum. Lamarck gave the word tunicata & vertebrata. Pisces classified by Rom

Define Energy Expenditure in Hot Environments? Energy expenditure in hot environments is increased by a small but significant amount because of additional work of ventilation a

CHROMOSOME S AND MOLECULAR HOMOLOGY - The DNA content of diploid cells is similar. Hoyer et al in 1965 showed that DNA of humans was 100% similar with chimpanzee and 94%

What are venous vessels, veins and venules? Venous vessels are each blood vessel that carries blood from the tissues to the heart. Veins and venules are venous vessels. Venules

Determine some assessment measures of Zinc? Measurement of zinc in plasma: This is the most common method. Fasting concentrations of less than 70 μg/litre suggests deficie

Abrasive action of water, ice and wind Water is an important mechanical weathering agent both in liquid as well as in the frozen state.  Rain water carrying sediments, ice glac

What is ventilation   A.  An increase in the hydrogen ion concentration in the interstitial spaces of the  brain stem leads to an increase in the duration of the respiratory cy