Genetics Animals

CLONING

Cloning is a creation of an organism that is an exact copy of another. This means that every single bit of DNA is same between the two. Clones have identical genetic make-up. It helps to generate animals with desirable traits. This may include genes, cells, tissues or entire organisms.

When we speak of cloning, we typically think of organism cloning, but there are actually three different types of cloning.

• Molecular-Cloning
  Molecular cloning focuses on making identical copies of DNA molecules in chromosomes. This type of cloning is also called gene cloning.

• Organism-Cloning
  Organism cloning involves making an identical copy of an entire organism. This type of cloning is also called reproductive cloning.

• Therapeutic-Cloning
  Therapeutic cloning involves the cloning of human embryos for the production of stem cells. These cells could be used to treat disease. The embryos are eventually destroyed in this process.

Cloning Techniques

There are basically three techniques in cloning mammals. 

The three techniques are:

Embryo twinning:

Once the egg is fertilized by sperm, the cell that is formed begins to divide. Once the cell begins to divide, the cells can be separated and implanted into the uterus of different mothers, the identical clones will be born from different mothers. This can only work if the cells are separated before the cells begin to differentiate.

Nuclear transfer:

In nuclear transfer a donor cell and an egg cell (oocyte) are used. The first thing that must happen is the egg cell must have all the genetic material removed, then the cell is forced into a dormant stage in which the cell shuts down but doesn't die (this dormant stage is called Gap Zero stage). Next the donor cell's nucleus is put into the egg cell using the process of either cell fusion or transportation. The egg cell is then prompted to form an embryo, by using electric waves. Next the embryo is implanted into a mother, exact copy of the donor cell will born.

Honolulu technique:

In the Honolulu technique, unfertilized eggs are used as the receiver of the donor nuclei. Once the nuclei are removed from receiver cells, the donor cell's nuclei are inserted into them. There is no culturing done on the cells. After one hour, the cell accepts the new nucleus. After five more hours, the egg cell is then placed in a chemical culture which jumpstarts the cell's growth, just like fertilization does in nature. In the culture is a substance that stops the formation of a second cell, which usually forms before fertilization. After the jumpstart, the cell develops into an embryo. This embryo can then be transplanted into a surrogate mother and then carried to term.

IMPORTANCE

1    Biomedical scientist plan to create animal with human diseases, so that cures can be experimented safely.

2       In testing of medicines animalC models such as mice are used. These mice are genetically engineered to carry disease-causing mutations in their genes, however, this process is time-intensive, requires trial-and-error experiments and several generations of breeding. Cloning would allow scientists to the reduce the time needed to make transgenic animal models, such as the mice, and the result would be a population of genetically identical animals ready to use for a study without the time-intensive process

3     In medicine cloning is used to find out about many genes that cause diseases, this is also known as gene therapy. Gene therapy is used to find cures for diseases that are caused by genetics. Scientists are using gene therapy to find cures for cancer and AIDS.

4    Instead of cloning livestock for consumption livestock is cloned to make breeding stock. This is a more time effective way to breed livestock, however, only cells from a high-quality carcass can b cloned to give rise to an animal that is able to  pass its superior genes to its offspring.

5     Cloning can make plants resistant to herbicides, pest damage, infections and diseases improving the quality of the crops we eat.