Key Differences In Bulb Development And Limb Regeneration

1. Many experiments were conducted during the 1950s and 1960s with chick embryos and they showed that two patches of tissue essentially controlled the development of the pattern of bones inside limbs.  Describe at

Axolotls are some of the most interesting amphibians in the world. Although they are gravely endangered, scientists continue to experiment on them because of their incredible ability to regrow limbs. Besides their amazing abilities, these creatures also have very interesting appearances, habitats, relationships, adaptations, and life cycles.

Many of us have all heard the saying that a “lizard can lose its tail,” and bizarrely enough it will grow back. This was always considered impossible for humans, an idea belonging in the realm of science fiction, but now the regeneration of tissue is an extremely realistic possibility. Despite some opinions, this process does not happen naturally, or take place as cinematically as one might imagine. Over the past decade, there have been major advances in regenerative medicine, commonly known as stem cell research. Stem cells are undifferentiated cells within the body that have the capability to specialize into any tissue. They are most commonly found in cord blood, bone marrow, organ donations, placenta, and embryos . Stem cells are seen by some as a new miracle treatment, encouraging many countries to invest in their research.

When a body part is lost the corresponding part of the brain is not able to handle the loss and rewires its circuitry to make up for the signals it was no longer receiving from the missing digit. The rewiring might occur in one of two ways. Perhaps nerve impulses in the sensory cortex begin to course down previously untraveled pathways. The second theory is that neighboring neurons in the cortex may actually invade the territory left fallow because sensations are no longer received from the missing limb.

All animals with limbs have a common design. If a batwing were to be formed from a person’s hand, make the fingers extremely long; a horse elongates the middle fingers and reduce and lose the outer ones; frogs elongate the bones of the leg and fuse several of them together. All in all, despite radical changes in what limbs do and what they look like, this underlying blueprint is always present.

During the third to eighth week of conception, fingers, arm bones, and toes are being formed. Limbs start off as buds that then extend outward. This is all due to the DNA that is in each and every cell in the body.

animal in the early stages of growth when it’s basic structure and organ development is forming.

These two features earlier are examples that we can see with our naked eyes, but the DNA make up that we cannot see with our eyes alone are also laid out the same as well. In the evolutionary pathway, the genes that turn on and off for humans and fish are related through the instructions on how they function. All living things with limbs have in common the Sonic hedgehog gene (Shubin, p. 53). The Sonic hedgehog gene can control the development of the limbs in these creatures. To determine if the development of vertebrate animals can be interpreted in the same way, or have the same effect, the injection of vitamin A was used to inject into a shark, mice, and chicken embryos to see if the results were the same. The results turned out that the injection of vitamin A has indeed changed the development of limbs in these embryos. The effects cause the shark to have a mirror image of its fin, and the mice and chicken have duplication of bones in the limbs (Shubin, p.56-57). It becomes clear of what will happen if

The Earthworm, starfish, frog, fetal pig, and human all have much in common; however, some have more in common than others. Many have a matching digestive system but not a matching skeletal or circulatory system. Thought numerous dissections we can compare and contrast the various animal systems and gain knowledge on more than just the external side of an animal.

These flatworms are bi-directionally regenerating creatures which means a cut body can form a brand new tail from the posterior cut and a new head from the anterior cut. Using this skill, they are able to clone themselves, and reproduce asexually. While taking down observations, there were tail droppings. Tail droppings occur when a planaria attaches itself to a surface and pulls away, separating into two pieces. This is one form of reproduction, the other form is called fragmentation. Fragmentation is just like tail droppings, but instead of separating into two pieces, the tail dropping divides up into more pieces. Furthermore, planarians have an abundant amount of stem cell-like cells that are capable of converting into the cell needed for regenerating tissue, and are available when it is required. When they lose a portion of itself, pale white coloured cells filled with stem cell-like cells starts to form, this is blastema. Those cells will transform into the desired cell and will begin to divide, which will result in a new body part to replace the missing part. This could be seen during the lab, the worms were distinctly transparent, or a pale colour, in the areas where they were dissected. These flatworms are organisms, and organisms need to eat, or get nutrients. Once their head is cut off and they are just a tail, it is really easy for them to obtain food. The cells in the tail will self-destruct to provide energy for the growing planarian until the head and tail are proportionate to each other, where it will then continue feeding and growing like before it got transected. Humans too, are capable of regeneration, but just to a certain extent. Everyday the human body creates more blood, new skin, and much more, which is regeneration. Unfortunately, limbs regenerating is unthinkable. That is why studying animals like the planarians and

It was thought earlier that stem cells stimpulates hairs to regrow after they fall out, but the scientists found that Tregs are the real effeiecnt factor behind the process.

In the year 1924 a paper was published by Hans Spemann and Hilde Mangold, this paper was known as the, “Organizer Paper” (Sander and Faessler, 2001). The Spemann- Mangold organizer, is also known as Spemann Organizer. This experiment showed the initiation of Siamese twins in a transplant experiment with salamander eggs (Robertis 2008). While doing this experiment, Mangold and Spemann called the dorsal blastopore lip in gastrulating frog embryo “the organizer”, the job of the organizer is for initiation which means 1) the organizer imitates gastrulation and also stops signals starting from the ventral side of the blastula from prompting the skin. 2) Separate the host and donor tissues into secondary embryo into an anterior-posterior and dorsal-ventral

Through research of the embryonic development of the ascidians, scientists were able to better understand the vertebrate gene function and regulatory networks of several processes. The ascidia genes involved in the formation of the notochord, which were shown to be analogous to those of tadpoles, and were consequently mapped in order to obtain information regarding gene function in vertebrates. In addition, the developmental processes in ascidia embryogenesis were studied in great detail, leading to advances in the conception of the regulatory network's involvement in governing notochord differentiation and also the process leading to the formation of the tail (Corbo et al. 2001).

Frogs, toads, caecilians, and salamanders are the members of the class Amphibian (amphi- meaning “on both sides” and bios- meaning “life”). These members always require water for reproduction. Most Amphibians undergo metamorphosis, which is a usually degenerative pathological change in the structure of a particular body tissue. And, in the case of Amphibians, it is the changing of a tadpole into

The Spemann Organiser has a major role in the development of the central nervous system in the embryos of amphibians. The cells of the Spemann Organiser have a unique ability to alter the surrounding cells’ fates, in a process known as induction. The discovery of the Spemann organiser garnered large amounts of attention, causing Spemann to win the Nobel Prize in Medicine, in 1935, for his work in the discovery of induction. The Spemann organiser, as it has roles in developing the central nervous system, must turn off signals that encourage cells to transform into, for example, skin cells, and to turn on signals for cells that induce the formation of the central nervous system. It does this by releasing a number of molecules, including Chordin, Follistatin and Noggin, the main focus of this essay being on the function of Chordin. Chordin results