Human beings have always strived for a disease free life. We have achieved great scientific progress through which it is now possible to alter the fundamental genetic code of life. It has enabled us to modify genomes of all types of living creatures, including animals, plants, and even humans. The Gene editing technology, also known as Genome editing or Genome engineering is a technique through which DNA is inserted, deleted, modified or replaced in the genome of a living organism.
The gene editing techniques affect different areas such as disease management, biomedical research, agricultural and environmental research, etc. Gene editing has transformed research and human disease cures. Agricultural scientists are interested in the technology’s potential to edit crops so that they can be made much more nutritious as well as drought resistant. Significant improvements have also been made in gene editing which has made it more precise.
Various harmful species of pests have been eliminated without altering ecological balance. In future it might make it possible to eliminate harmful disease affecting humans that will reduce human sufferings. It will also prove effective in de-extinction efforts and may also create new and healthier foods that will reduce hunger and malnutrition. Thus, it has huge potential that could make the world a better place to live.
Cutting and Pasting DNA-CRISPR
The editing of genetic material is done using CRISPR-Cas9 technology, also known as molecular scissors. It is a dynamic and precise tool that allows scientists to essentially cut and paste DNA at any location and potentially repair or alter defective genes. It is used to remove, add or alter specific DNA sequences in the genome.
The CRISPR-Cas 9 system consists of two key molecules that introduces changes in the DNA. These are
• Cas 9 It is an enzyme that can cut the DNA strands at specific locations so that the desired bits of DNA can be added or removed to obtain desired results.
• Guided RNA This is a small piece of pre-designed RNA sequence located within a longer RNA which binds to DNA and guides the Cas 9 enzyme towards the right part of the genome. It makes sure that the Cas 9 enzyme cuts the DNA at a precise point.
• The RNA guide is designed to find and bind to a specific sequence in the DNA. The RNA guide has RNA bases that are complementary to the target DNA sequence. This means that guided RNA will bind to the target sequence only. The Cas 9 enzyme follows the guide RNA and makes cut in the DNA. At this stage, the cell recognises that DNA is damaged and tries to repair it through mutation. For decades, the scientists used chemicals or radiations to cause mutations. However, there was no way of controlling where in the genome the mutation would occur. The CRISPR-Cas9 technology has given them a versatile tool to edit the gene wherever they desire to. The CRISPR Cas 9 method is the most reliable and cheapest tool to cut and paste DNA at specific points.
Emergence of Gene Editing
The CRISPR clustered regularly interspaced short Palindromic repeats, were discovered in genomes of prokaryotes such as E. coli Bacteria in 1987 by Japanese scientist Yoshizumi Ishino. But, its use was successfully demonstrated in 2012 by a group of scientists who discovered that by designing guide RNA to target a specific region in the genome, the CRISPR Cas 9 system can be used as a cut and paste tool to modify genomes. Since then, it has been used to seamlessly cut and paste DNAS to switchoff trouble making genes.
It was recognised that E.coli bacteria has a built-in gene editing system that they respond to invading pathogenes such as viruses. Using the CRISPR, the bacteria cuts the part of virus DNA and keep a bit of it behind to help them recognise and defend against the virus the next time it attacks. Scientists adapted this system so that it could be used in other cells from animals, plants, humans etc. The CRISPR gene editing technology has been used for various purposes to make lives better.
Uses of Gene Editing Technology
The CRISPR technology has enabled humans to experiment with newer techniques as the technology for editing genes has come far. The gene editing technology has following applications
• Agricultural Improvements
Gene editing has resulted in improvements in agriculture all over the world. It has improved plant yields, crop quality and enabled us to make more disease resistant and better quality crops. It has enabled us to domesticate wild crops that are useful for eradicating hunger and malnutrition. Using this tool, a large number of crop varieties have been cultivated that have improved agricultural performance. There have been sweeping changes to agricultural technologies in breeding. This technique has the potential to create plants that are disease free. With climate change, the world requires more crops that can tolerate a wide range of weather conditions. Gene editing has the potential to create such crop varieties.
• Genetic Research
CRISPR gene editing tool has been used to deliver superior genetic models for fundamental disease research, drug screening and therapy development. There have been improvements in rapid diagnostics, in-vivo editing and correction of heritable conditions. It also holds potential in treating various complex conditions such as cancer, tuberculosis as well as HIV infections. The genetic research is currently focussed on single gene disorders such as systic fibrosis, haemophilia and sickle cell disease. Scientists are working to boost the functions of immunity T-cells so that immune systems can detect and kill the cancer cells.
•Medical Treatment
Gene editing technologies have potential to alter disease causing genes and treat severe medical conditions. Researchers have been able to edit genes in human embryo to try to correct a faulty gene which caused an inherent blood disorder. It was not accepted to the scientific community due to ethical and moral concerns but it has showed that gene editing technologies have huge potential in resolving issues and diseases that have been plaguing the human civilisation for long periods.
The removal of faulty gene and cure of hereditary diseases has been proven to be a blessing for even the future generations of children. This also will lead to lower incidence of diseases in the world.
•Manufacturing Cleaner Biofuels
CRISPR gene editing technology has been used to alter gene of algae with high biofuel yield. This has enabled the researchers to double the yield of biofuel from the algae. The oil has been processed in existing refineries and used like a conventional fuel. This has enabled the researchers with a new tool to fight global warming through the use of more environment friendly and less degrading fuels. Gene editing has the potential to solve Global energy crisis.
•Developing New Drugs
New and more effective drugs and medicines can be made using gene editing technology. These medicines can be used to treat heart diseases, blood disorders so that these diseases can be completely eliminated from human species. Many partnerships have been made with pharmaceuticals companies to develop modern age drugs to cure existing disease and cure future diseases in humans.
Concerns with Gene Editing
Several issues are associated with gene editing. These include
Issues with GM Crops
Genetically modified crops have higher yields and better nutrition but concerns related to GM crops have not been addressed properly. These foods have been said to create allergic reactions in many people and thus their efficacy has not been tested fully on people of all ages, genders etc. Issues have also been highlighted in various researches that CRISPR Cas 9 edited agricultural crops are also said to have triggered cancer in various people. In India where there are a diversity of races having different genetic composition, issues related to the effects of GM crops on these diverse people should be addressed.
Illegal Experiments
Gene editing technology has been used to carry out illegal experiments by editing genes and creating designer babies’. These experiments do not have certificates and authorisation from the scientific medical community. These experiments are not certified and may cause potential harm to the gene edited embryo. Altering human being genes withouany approved technique may have unintended consequences for human lives. Though there are no guidelines on editing genes in human embroys but scientific community has evolved a general consensus that clinically gene editing should not be used on human embroys for experimentation.
Genetic Inequality
Through gene editing technology, wealthy parents can afford to edit the genes of their offsprings and lead to genetic haves and hav nots. It would lead to greater inequality than the present world already lives with. This could also lead to genetic discrimination among the poor and the rich. Thus, inequality will be established opposite to what the technology is to be used for
Germline Modification
Germline editing means changing the genes passed the children and future generations, creating genetically modified people. The changes made in germline would be passed on to future generations, thus, passing on the modifications to even new people that would be added to the current generation. Germline modification has been considered unsafe and socially unacceptable. It would lead to random mutations, extrapolation of the genetic changes, harmful consequences for the future generations, negative impact of social perception among the members of the society.
Conclusion
Gene editing has taken technological innovations to newer levels. A lot of is still to be made as technological and ethical hurdles still stand between humans and the use of genome editing applications. Experiments and tests should be conducted so that it is subject to appropriate scrutiny by the regulators and their use must be controlled to prevent commercial misuse. While scientists are still working to determine whether the gene editing technology is safe and effective for use of the people, the current application of the technology must be regulated for safe use. It must be remembered that any technology is for the betterment of humankind. It must be ensured that social concerns are addressed before the use of gene editing. The government, private sector and scientific community must work together to make gene editing safe for use.
Thank you very much for reading this article“What is Gene Editing, Meaning, Definition, DNA-CRISPR, Uses of Gene Editing”
