Back to: MICROBIOLOGY 500 LEVEL
Welcome to class!
My intelligent microbiologist-in-training, I’m so glad to see you in class today! You’re doing an amazing job so far, and today we’re learning about something that’s not just shaping science in Nigeria but across the world—CRISPR. This isn’t just any science term; it’s one of the biggest scientific breakthroughs of our generation. And guess what? It all started with a humble bacteria trying to protect itself—imagine that!
Let’s understand the History and Mechanism of CRISPR, using simple examples and relatable ideas, just like we always do.
History And Mechanism Of Crispr
History of CRISPR
CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats. Sounds complex, right? But don’t worry, we’ll keep it human.
Back in the 1980s, scientists studying bacteria noticed some strange repeated patterns in their DNA. These patterns didn’t make much sense at first, so they were quietly documented and not really understood.
Fast forward to the early 2000s, scientists discovered something amazing: these repeated DNA sequences were part of a defence system. Bacteria were using them to defend themselves against viruses—yes, even bacteria can catch viruses!
This discovery led to one of the most powerful gene-editing tools ever created. In 2012, researchers Jennifer Doudna and Emmanuelle Charpentier developed a way to use the CRISPR system to cut and edit DNA precisely—like a pair of molecular scissors. Their work won the Nobel Prize in Chemistry in 2020.
So, what started in bacteria is now used in treating diseases, modifying crops, and even fighting sickle cell anaemia!
Mechanism of CRISPR
Let’s explain CRISPR using a real-life story. Imagine a school in Abuja where students have notebooks. Sometimes, bullies (viruses) sneak in and scribble bad things in their books. So, the students start copying the names of these bullies and keeping the records in a “watchlist” notebook. If the bully ever returns, the student quickly recognises the name and crosses it out with a red pen. That’s how CRISPR works in bacteria!
Here’s a breakdown of the mechanism:
Invasion – A virus attacks a bacterium and injects its DNA.
Capture – The bacterium cuts out a piece of the viral DNA and stores it in its own genome, like a memory.
Guide RNA creation – When the virus comes back, the bacterium makes an RNA copy of the stored DNA (called guide RNA).
Cas9 Activation – The RNA teams up with a protein called Cas9, which acts like scissors.
Attack and destroy – The guide RNA leads Cas9 to the matching viral DNA, and Cas9 cuts it up—destroying the threat.
Now, scientists use this same system to edit any DNA they want: in humans, animals, plants—you name it.
Applications in Real Life
In Nigeria, researchers can use CRISPR to study genes in crops like cassava or yam and improve their resistance to disease or drought.
It’s also being tested for treating genetic conditions like sickle cell anaemia, which affects many Nigerians.
Summary
- CRISPR began as a natural defence system in bacteria to fight off viruses.
- Scientists adapted this system to create a powerful gene-editing tool using guide RNA and Cas9 protein.
- CRISPR allows precise cutting and editing of DNA and is now used in medicine, agriculture, and research worldwide.
Evaluation
- What does CRISPR stand for?
- Briefly describe how bacteria use CRISPR to defend against viruses.
- Mention one application of CRISPR that is relevant to Nigeria.
You’ve just unlocked one of the most revolutionary discoveries in modern science—and you understood it in a way that connects to your own world. Remember, the future of CRISPR in Nigeria depends on bright learners like you. Keep your mind open, your heart curious, and your spirit unstoppable. You’re doing great things already—see you in the next exciting Afrilearn class!