CRISPR

By Samanvita Bellur Raghavendra

CRISPR gene editing has been one of the greatest discoveries of the 21st century. This revolutionary discovery has had diverse applications in fields of medicine and agriculture. 

CRISPR- abbreviation of clustered regularly interspaced short palindromic repeats,  is a genetic engineering technique in molecular biology by which the genomes of living organisms may be modified. It is based on a simplified version of the bacterial CRISPR-Cas9 antiviral defense system. 

Now, how did this all begin?

The first description of what would later be called CRISPR occurred in 1987, when researchers in Japan, led by Ishino et al., accidentally cloned part of a CRISPR sequence in Escherichia coli while studying the iap gene. They noticed short, repeated DNA sequences interspersed with unique spacers, which was unusual compared to typical consecutive repeats in DNA. In the early 1990s, Francisco Mojica studied similar sequences in archaea, fully characterizing the repeats and proposing that they might serve a functional role in the cell.

By 2000, Mojica and colleagues identified that these sequences were interspersed with DNA fragments from viruses (bacteriophages), suggesting a role in bacterial defense. Around the same time, other researchers, including Bolotin and Horvath, studied Streptococcus thermophilus and experimentally demonstrated that CRISPR sequences could integrate new viral DNA into the bacterial genome, providing immunity against future diseases.

In 2012, Jennifer Doudna and Emmanuelle Charpentier harnessed the CRISPR-Cas9 system for precise genome editing. They showed that by designing a guide RNA, Cas9 could be directed to cut any DNA sequence in a controlled manner, enabling targeted gene modification in living cells. This breakthrough transformed CRISPR from a bacterial curiosity into a powerful tool for genetic engineering, with applications in medicine, agriculture, and biotechnology. Doudna and Charpentier were awarded the 2020 Nobel Prize in Chemistry for this work.

CRISPR actually is way more useful than we think.

Researchers are now investigating CRISPR's ability to create custom immunotherapies for cancer patients. By editing immune cells to better target cancer cells, CRISPR could enhance the effectiveness of existing treatments.

CRISPR allows scientists to create accurate models of diseases, such as Alzheimer's, by editing genes in induced pluripotent stem cells (iPSCs). This helps in understanding disease mechanisms and testing potential therapies

Just like this, innovations and scientific discoveries have made our lives easier on this planet. Such discoveries are great signs of human evolution , and truly show how far we have come.