How would you edit a specific nucleotide in a genome?

Question

Accepted Answer

Hello, here's our next question. Which of the following gene editing technologies does not involve creating double stranded DNA breaks. Choice A CRISPR cas nine B base editing C zinc finger nucleases Z F N S or D transcription activator like effector nucleases talons. Well, one thing we want to recognize looking over our answer choices is that choice. A CRISPR Cas nine and then C and D the zinc finger nucleases and the talons all involve nucleases, cas is a nucleus and then the word nucleus is right in the names of C and D and A nucleus cleaves DNA. So just by looking at those kind of looking them all over, we're going to be looking at choice B base editing as a technology that does not involve double strand of DNA breaks. Since the only choice here that doesn't involve a nucleus. And indeed each of those ABC or excuse me AC and D involve a strategy. You've created an artificial complex of a nucleus and some way of targeting a specific DNA sequence for editing. So in CRISPR cast nine choice A, you have a G R N A that guides the CAS enzyme to a sequence, you want to cleave out. In C the zinc finger nucleases, you have a zinc finger binding domain. So zinc that can target a specific DNA sequence and then the nucleus can cleave it. And in the talons in choice D again, you have a DNA binding domain harness to a nucleus that allows you to target a specific DNA sequence for cleavage. But in base editing, that's the ability to actually change one nucleotide to another without having to cleave the double strand of DNA. So this is obviously a technique that would result in less potential for DNA damage in the editing process. So it's more targeted, more controlled and reduces the risk of DNA damage and off target effects that you don't want to create. So this is a very promising technique for safer gene editing. So choice B base editing is a gene editing technology that does not involve creating double stranded DNA breaks. See you in the next video.

How would you edit a specific nucleotide in a genome?

Key Concepts

CRISPR-Cas9

Nucleotide Structure

Homology-Directed Repair (HDR)

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