Over the past few decades, the fields of biology and medicine have been revolutionized by the advances in gene editing. The discoveries made have been the focus of much research and have even earned the 2020 Nobel Prize in Chemistry for scientists Jennifer Doudna and Emmanuelle Charpentier. But what exactly does the term “CRISPR” mean, and what is the future of this powerful tool?
CRISPR stands for “clustered regularly interspaced short palindromic repeats”. Basically, they are repetitive DNA sequences discovered in bacteria that exactly match viral sequences. They are first introduced through viral infection and become part of the bacteria’s DNA. When infected later, the DNA is transcribed into RNA that guides a nuclease to cut the viral DNA, allowing for protection. These nucleases are named “CRISPR-associated,” or “Cas” for short.
Now, more broadly, DNA can repair itself when it detects double-stranded breaks by replacing the breaks with new pieces of DNA. So the idea is that if we can create breaks in DNA at places where there is a problem (like a mutation), we can trigger the natural repair of the genome and even control the genetic information of the cell. This is the basis of CRISPR, which has been described as “genetic scissors.”
CRISPR technology has already been used in a wide range of organisms, such as mice, pigs, and monkeys. It has also been used to treat humans’ diseases such as cystic fibrosis. However, this raises a multitude of ethical concerns, as this technology would allow us to create “designer” humans. For example, a scientist in China was imprisoned for using CRISPR to alter human embryos. For this reason, there is now an international moratorium, or temporary prohibition, of germline editing.
Hopefully you have learned a little about CRISPR and gene editing. If you would like to learn more about this topic, please feel free to use the links below and watch Jennifer Doudna’s TED Talk.
Links for further reading:
What is CRISPR/Cas9? National Institutes of Health
What is CRISPR? Innovative Genomics Institute
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