CRISPR Flashcards
What is CRISPR?
basically a cut-and-past tool for DNA editing, a gene editing system where point mutations are accurately introduced to genomes. It basically finds and changes specific genes.
What does CRISPR stand for?
Clustered
Regularly
Interspaced
Short
Palindromic Repeats
What are the two parts of the CRISPR system?
- Guiding RNA
- the protein or enzyme Cas9 endonuclease
Why do we need the guiding RNA do?
it recognises the sequence of DNA that needs to be edited and
also contains the nucleotide sequence that is complementary to the gene you want to edit
Why do we need the Cas9 endonuclease enzyme?
it can cut DNA
So what is the CRISPR process using the two parts?
a gene editing tool can be directed to a specific part of a genome with very high accuracy. then the tool can cut and edit the gene of interest
What is the max number of base pairs than can be inserted, deleted or substituted with CRISPR?
20
What is the potential of CRISPR?
CRISPR could be used to:
- improve targeted gene therapy
- reverse point mutations that cause diseases (like cystic fibrosis)
What are the pros of CRISPR?
- efficient
- ## relatively low cost
What can CRISPR actually be used for?
- researching molecular biology
- improving gene cloning
- producing transgenic species
What is the natural origin of CRISPR?
the CRISPR-Cas9 system evolved in some prokaryotes to fight viruses by using a mechanism (CRISPR DNA sequence and the Cas9 enzyme) to find, using the CRISPR DNA sequence as a template, and remove virus DNA and prevent it from replicating.
How have human manipulated the natural CRISPR-Cas9 mechanism?
by changing the template DNA, used find the target section of genes, humans can choose what gene section the Cas9 is looking for and edit the genome of any organism
CRISPR is usually used to ______ genes (add, take out, edit)
take out or knock out
CRISPR can be used to add genes in too, which produces what?
transgenic organisms
What replaces the natural CRISPR sequence to allow this process to be used by humans?
a guide RNA (gRNA) is instead provided ot the Cas-9 molecule. DIfferent template = different instructions to Cas9 molecule on where to cut the DNA
What is the process of using the gRNA and the Cas9 molecule?
- Scientists identify their target genome or DNA section
- They create a specific guide RNA to recognise that particular genetic sequence (basically a strand of complementary nucleotide bases that will exactly match when over the target DNA section)
- The guide RNA is attached to the DNA cutting enzyme Cas9
- The combined guide RNA-Cas9 complex is introduced into the chosen cells
- The guide RNA-Cas 9 complex moves along the DNA of the chosen cell, looking for the target sequence
- When a sequence on the DNA matches the specific guide RNA, the genome is located, and the enzyme cuts the gene
- if desired, the scientist can now edit the existing genome, by modifying, deleting or inserting a new sequence in the cut. This insert could be a gene from a different organism (transgene) or even jsut a normal gene to replace the defective one
What do scientists hope to do with CRISPR- Cas9 in the future?
to make critical advamces in patient care or even cure life long inherited diseases
