CRISPR (Clustered Regularly Interspaced Short Palindromic Repeat) has emerged as a groundbreaking technology that allows scientists to edit genes precisely in living cells. It is a molecular scissor that can cut DNA at specific locations and insert, delete, or replace genes.
Origin of CRISPR
CRISPR is the defense system used by bacteria and archaea to protect themselves against virus attacks. It consists of the Cas9 enzyme which cuts the DNA at specific points and a group of base sequences that code for a guide RNA which, as per its name, guides Cas9 to its destination. In bacteria and archaea, CRISPR serves as a memory storage, it cuts and retains parts of viral DNA in the guide RNA so if the same virus invades the cell again, Cas9 can readily destroy its DNA.
However, scientists soon discovered the endless potential CRISPR carried for the world of gene editing. In 2012, Dr. Emmnuelle Charpentier and Dr. Jennifer Doudna demonstrated that if the guide RNA is altered then Cas9 can be custom-made to cut DNA at sites complementary to it, meaning scientists can control specifically which gene in the DNA is being changed which was previously not possible without affecting other genes.
Applications of CRISPR
1) Genetic disease treatment
CRISPR can correct faulty genes that cause genetic diseases by inserting a healthy copy of the gene or correcting the mutation. It can also be used to disable harmful genes, switching them off and preventing their effects. CRISPR is used to give gene therapy and is already under test for the potential treatment of sickle cell anemia, cancer, Huntington’s disease, HIV, etc.
2) Agriculture
CRISPR can introduce specific viruses, pests, and disease-resistant genes to crops, a process much faster than the traditional method of selective breeding over generations. CRISPR was used to make modified wheat lacking gluten making it edible for people with gluten intolerance. Not only that, certain crops can also be edited to produce fewer allergens.
In 2023, the first CRISPR-edited salad entered the US market. Pairwise, a gene-editing startup, engineered mustard greens, a highly nutritious green with a strong bitter taste when eaten raw, by removing the gene responsible for the unpleasant taste. This way, they hoped that consumers would choose mustard greens over other less nutritious greens.
3) Anti-aging
Scientists are identifying genes contributing to aging. CRISPR could potentially edit these genes to slow down or reverse their effects. Telomeres, protective caps on chromosomes, shorten with age, and as they do, the cells slowly lose their ability to divide for tissue repair and cell replacement. CRISPR could potentially lengthen telomeres, extending cell lifespan and delaying aging. Aging is associated with DNA damage accumulation. CRISPR could be used to improve DNA repair mechanisms, reducing the risk of age-related diseases.
CRISPR can now be applied topically to a few centimeters below the skin’s surface. It might not be far-fetched to use a topical lotion based on CRISPR to promote the production of collagen or improve the elasticity of skin delaying the appearance of wrinkles.
Ethical consideration
While CRISPR offers immense potential, it raises ethical questions about the manipulation of human genetics, including altering the genetic makeup of future generations. The long-term effects of gene editing using CRISPR are unknown, and there is a risk of unintended consequences that may not become apparent for years.
In conclusion
This revolutionary tool has the potential to transform various fields, from medicine to agriculture. As research advances, we should anticipate even more unique applications for CRISPR. However, it is crucial to approach CRISPR with caution and address the ethical implications associated with its use.
written by Shuiba Ayman Rafiq
