Transgenic Animals
What is a Transgenic Animal?
A transgenic animal is an animal that carries genes from another animal or species. This is achieved by introducing the desired gene into an embryo which can either change or get rid of the function of another gene in the embryo. Most of the transgenic animals in existence are mice because they were the original subjects the new technology was tested on. The definition of a transgenic animal is “an animal in which there has been a deliberate modification of its genome”
How is a Transgenic Animal Made?
There are three main methods of creating transgenic animals. A DNA microinjection, retrovirus-mediated gene transfer, and embryonic stem cell-mediated gene transfer. Those are some very big words, so let’s break them down.
A DNA microinjection consists of injecting the desired gene into the nucleus of the cell of the recipient. The recipient is then cultured in vitro (in a lab) then later transferred to a recipient female mother. The baby animal will then be born with the modified genes
Retrovirus-mediated gene transfer is the act of getting a virus to carry the genetic material using RNA instead of DNA. This results in something called a chimera which is an organism made of tissues and has a wide range of genetic constitution. The chimera will then inbreed until is homozygous and carries the desired gene in every cell.
Embryonic stem cell-mediated gene transfer involves isolating the stem cells that can transform into any part of the body and directly injecting the gene into them. The benefit of this method is that it can be performed in the cell stage as opposed to using a live specimen.
Why do Transgenic Animals Exist?
Transgenic animals are created for a wide variety of fields of profession. A few examples of these are medicine, agriculture and they even have industrial applications. In agriculture, a transgenic animal can be beneficial for creating an animal that produces more meat or milk, is disease resistant, or will make breeding much easier by producing the exact desired type of animal. An example of transgenic animals in medicine are pigs which have their proteins replaced with human ones to have human organs that can be used for transplants. There is a far greater need than the supply available for human organs. Thousands of people die each year because they don’t have an organ available to replace theirs. The ability to grow organs that function and transplant them would be a major step forward in the medical industry. In an industrial setting, transgenic animals could be the key to developing certain fabrics and materials quickly and effectively. An example this is is the goat’s scientists in Canada gave spider genes. The goats then produced spider silk along with their milk. If refined, spider silk is very light tough and can have many applications in anything from tennis racket strings to military uniform.
The Greatest advancement in Transgenic Animals
Since the discovery of the genetic structure by Watson and Crick in 1953, molecular biology has become more and more widely used. Combining biochemistry, genetics, and a variety of other biology-related topics, there have been many advancements in this field. With this, scientists have been able to create transgenic mice, chickens, pigs and even primates as of late. So, the arguably most important discovery in transgenic animals was the discovery of the genetic structure.
How is this form of biotechnology changing the world as we continue to advance towards the future?
Like I mentioned above, the latest advancement in this field is the successful creation of a transgenic primate. Hopefully, by doing this, these primates will be able to act as the most accurate model for how diseases will affect humans. The hope is that eventually, we will be able to create therapies and cures to eliminate or cure these genetic diseases.
Sources : http://www.actionbioscience.org/biotechnology/margawati.html
http://www.transgenicanimals.info/examples-of-transgenic-animals/