Induction of mesoderm in amphibians, Biology

Assignment Help:

Induction of Mesoderm in Amphibians

Earlier you know that an event that precedes neural ectoderm induction in amphibians is the induction of mesoderm. Until 32 cell stage in amphibian blastulae there are only two cell sorts. In animal hemisphere there are small ectodermal cells and in the vegetal hemisphere there are large endodermal cells. A third cell type from which mesoderm develops is made in the equatorial region of the embryo throughout early blastula stage.

Fate map of Xenopus embryo reveals that equatorial cells in contact with both of the animal and vegetal cells in the equator of blastula are precursors of mesoderm. How is the fate of the equatorial cells as prospective mesoderm cells determined? Either the ooplasmic determinants like intrinsic factors or cell interactions as extrinsic factors may play a role in such type of a determination. To test one of the two probabilities, the blastulae were divided into explants of animal, equatorial and vegetal cells and cultured independently. Animal cells that are developed into ectoderm cells, vegetal cells into endoderm cells and the equatorial cells into mesoderm cells. Though, if the animal cells were recombined with vegetal cells and cultured, they formed mesoderm cells also suggesting the probability that mesoderm formation is not exclusively dependent on ooplasmic determinants. The equatorial cells develop into mesoderm cells possibly since the adjacent vegetal cells secrete some inducing substance which influences the adjacent cells of the equatorial region inducing them to become mesodermal cells. In the general blastula, the animal hemisphere cells differentiate only into ectoderm since they are widely separated from the vegetal cells by the blastocoel and thus are too far from the source of inducer.


Related Discussions:- Induction of mesoderm in amphibians

Respiration, abnormal lung volumes and capacities

abnormal lung volumes and capacities

Define composition of the diet during pregnancy period, Define composition ...

Define composition of the diet during pregnancy period? The composition of the diet during pregnancy should be the same as for a non- pregnant woman; hence the contribution to

What is the advantage of having a family of protein, Why do we need a famil...

Why do we need a family of proteins for cell adhesion (what is the advantage of having a family of proteins?)

Mutualist exploration of cellulose digestion, Q. What is meant by "mutualis...

Q. What is meant by "mutualist exploration of cellulose digestion", a phenomenon that occurs in some mammals and insects? Herbivorous animals eat great amounts of cellulose a s

What are the two techniques of submerged implants, Submerged implants Decis...

Submerged implants Decision has to be made between two techniques. These techniques are: Technique 1: Stage two using a mucoperiosteal flap Technique 2: Stage two done wi

Adrenaline and noradrenaline, Both these neurotransmitter strengthen memory...

Both these neurotransmitter strengthen memory when they are released into the blood stream following learning. Stressful events stimulate release of stress hormones from the adrena

Types of amoeboid movements, Types of Amoeboid Movements As the amoeba...

Types of Amoeboid Movements As the amoeba's cell body throws out one or a few pseudopodial lobes, a temporary rear end or uroid is pulled along. The central, more fluid protop

Effects of smoking on oesophagitis, Q. Effects of smoking on oesophagitis? ...

Q. Effects of smoking on oesophagitis? 1. A decrease in pyloric sphincter pressure which may predispose an individual to duodenal ulcer. 2. An alteration in the nature of ga

Human eye, Difference between rod and cone cells

Difference between rod and cone cells

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