DNA Recombination, Biotechnology, and Genetic Engineering
DNA Recombination
DNA recombination is a process that allows the combination of DNA fragments from different origins. This can be done in a laboratory using cellular machinery and enzymes. DNA can be cut into fragments using enzymes called restriction endonucleases. The resulting fragments have cohesive or sticky edges complementary to other DNA cut with the same enzyme, so you can join different fragments of recombinant DNA origin. In this way, it is possible to introduce DNA into the genome of other organisms. To make recombinant DNA from a donor to the recipient cell, a gene vector is widely used in gene transfer. Vectors that carry other genes are called markers and can identify transgenic cells. Usually, these are antibiotic resistance genes or luminescence genes.
Amplification of DNA
Bacterial propagation also causes the amplification of the inserted DNA. It is an in vivo procedure, slow and costly. In 1983, Kary Mullis developed a device to get copies of DNA in vitro quickly, like a photocopier, using the DNA sample to be amplified, deoxyribonucleotides, and enzymes. This method, called PCR (Polymerase Chain Reaction), is very useful for obtaining massive amounts of DNA copies. It is also widely used in paternity testing.
Directed Mutations
Mutations are changes in DNA:
- Gene mutations: Affect a single gene.
- Chromosomal mutations: Affect the structure of chromosomes.
- Genomic mutations: Affect the number of chromosomes.
Human Genome
The Human Genome Project was a splendid achievement in the fight against diseases of genetic origin. Particular attention should be paid to the ethical implications of this new situation, always preserving human dignity.
Biotechnology
Modern biotechnology is based on the application of current knowledge about genetic engineering. However, biotechnology presents non-negligible drawbacks, including a lack of control over genetically engineered organisms, the production and stockpiling of biological weapons, and the appearance of new species.
Medical Biotechnology
Uses:
- Treatment of diseases that previously did not have a cure or had very expensive treatments.
- Development of safer vaccines.
- Early diagnosis of genetic diseases.
Obtaining Proteins Used as Drugs
Some people do not make certain proteins essential to life. These proteins can be extracted from normal tissues. Now, a gene that encodes a human protein of pharmacological interest can be inserted into an organism. When these organisms are colonized, they express their genome and the introduced gene. The advantages are multiple: possibilities of product contamination are minimized, there is also full and continuous control of the synthesized hormone, and their manufacture is unlimited.
Gene Therapy
It consists of modifying the abnormal genes to prevent or cure a disease once it has manifested.
Agricultural Biotechnology
The objectives for agriculture are:
- To make plants resistant to herbicides, insects, bacteria, and viruses.
- To increase photosynthetic efficiency.
- To lower the nutritional needs of plants.
- To improve the quality of products.
- To produce compounds of commercial interest.
Livestock Biotechnology
Transgenic animals of interest now are those that produce proteins and other compounds of pharmacological interest. These are used for research studies on gene regulation, cell differentiation, and embryonic development.
Bioremediation
There are species that degrade oil and pesticides, and others that accumulate metals naturally. Genes involved in these processes can be isolated and subsequently introduced into other organisms.
Assisted Reproduction
The purpose of these techniques is to enable couples to have children, using preimplantation genetic diagnosis. A couple is considered sterile when they cannot have children after twelve months of sexual intercourse without using contraception. The techniques used for assisted human reproduction vary according to the problem.