When Will We Be Transhuman? We can at least pretend to know where it is we want humanity to go.
January Transgenic mice, rats, rabbits, pigs, sheep, and cows have already been created. A natural protein produced in the milk of transgenic cows like this one kills the bacteria that cause animal mastitis.
Nowadays, breakthroughs in molecular biology are happening at an unprecedented rate. One of them is the ability to engineer transgenic animals, i. The technology has already produced transgenic animals such as mice, rats, rabbits, pigs, sheep, and cows.
Although there are many ethical issues surrounding transgenesis, this article focuses on the basics of the technology and its applications in agriculture, medicine, and industry. What is a transgenic animal? There are various definitions for the term transgenic animal. The Federation of European Laboratory Animal Associations defines the term as an animal in which there has been a deliberate modification of its genome, the genetic makeup of an organism responsible for inherited characteristics.
The nucleus of all cells in every living organism contains genes made up of DNA. These genes store information that regulates how our bodies form and function. Genes can be altered artificially, so that some characteristics of an animal are changed.
For example, an embryo can have an extra, functioning gene from another source artificially introduced into it, or a gene introduced which can knock out the functioning of another particular gene in the embryo.
Animals that have their DNA manipulated in this way are knows as transgenic animals.
The first successful transgenic animal was a mouse. The two most common reasons are: Transgenic animals are useful as disease models and producers of substances for human welfare. Some transgenic animals are produced for specific economic traits.
For example, transgenic cattle were created to produce milk containing particular human proteins, which may help in the treatment of human emphysema. Other transgenic animals are produced as disease models animals genetically manipulated to exhibit disease symptoms so that effective treatment can be studied.
For example, Harvard scientists made a major scientific breakthrough when they received a U. Since the discovery of the molecular structure of DNA by Watson and Crick inmolecular biology research has gained momentum. Molecular biology technology combines techniques and expertise from biochemistry, genetics, cell biology, developmental biology, and microbiology.
The insertion of a foreign gene transgene into an animal is successful only if the gene is inherited by offspring. The success rate for transgenesis is very low and successful transgenic animals need to be cloned or mated. To date, there are three basic methods of producing transgenic animals: DNA microinjection Retrovirus-mediated gene transfer Embryonic stem cell-mediated gene transfer Gene transfer by microinjection is the predominant method used to produce transgenic farm animals.
Since the insertion of DNA results in a random process, transgenic animals are mated to ensure that their offspring acquire the desired transgene. However, the success rate of producing transgenic animals individually by these methods is very low and it may be more efficient to use cloning techniques to increase their numbers.
For example, gene transfer studies revealed that only 0. Embryonic Stem Cell-Mediated Gene Transfer The presence of transgenes can be tested at the embryonic state in this third method.
How do transgenic animals contribute to human welfare? The benefits of these animals to human welfare can be grouped into areas: Agriculture Medicine Industry The examples below are not intended to be complete but only to provide a sampling of the benefits.
Agricultural Applications Transgenesis will allow larger herds with specific traits. When technology using molecular biology was developed, it became possible to develop traits in animals in a shorter time and with more precision.
In addition, it offers the farmer an easy way to increase yields. Scientists can improve the size of livestock genetically. In the past, farmers used growth hormones to spur the development of animals but this technique was problematic, especially since residue of the hormones remained in the animal product.
Disease-resistant livestock is not a reality just yet.
Medical Applications Transplant organs may soon come from transgenic animals. For example, about 5, organs are needed each year in the United Kingdom alone. This transgenic milk is a more nutritionally balanced product than natural bovine milk and could be given to babies or the elderly with special nutritional or digestive needs.Human organ transplantation faces a significant challenge because the need for this procedure far exceeds the availability of donor organs.
Each year fewer than half the people on transplant waiting lists receive organ transplants.
Although transplants from animals to humans, called xenotransplants, might benefit the thousands of patients waiting for human organs, the possibility that they could spread some unknown animal virus into the human population has caused concern and delayed research experimentation.
List of Cons of Organ Donation. 1. Prolonged suffering of the family of a donor Most of the time, the family of the deceased donors are not informed that the body will be kept on life support until the organ will be harvested.
Human organ and tissue transplantation (allotransplantation) is common surgery in the United States. The procedure is carried out in order to save the lives of individuals suffering organ failure and serious disease. Examples of this include kidney, heart, liver, and lung transplants.
Although, xenotransplants could revolutionize the medical industry by implementing technology that combines human and animal DNA, it is clear that there should be restrictions on it due to past and expected complications and concerns.
Organ xenotransplants could include whole hearts, lungs, livers, kidneys or pancreases. Tissue xenotransplants could include skin grafts for burn patients, corneal transplants for the visually impaired, or bone transplants for limb reconstruction.