CRISPR Flashcards
(20 cards)
What does CRISPR stand for?
Clustered Regularly Interspaced Short Palindromic Repeats.
What is CRISPR-Cas9 used for?
Editing genomes and modifying genes.
Where are CRISPR sequences found?
In the genomes of prokaryotic organisms.
What is the origin of CRISPR sequences?
From viruses that previously infected the prokaryote.
What is the function of CRISPR in bacteria?
Acts as an antiviral immune system.
What are the three parts of a CRISPR locus?
1) cas genes, 2) Leader sequence, 3) Repeat-spacer array.
What molecule is transcribed from the CRISPR array?
pre-crRNA (precursor CRISPR RNA).
What does the Cas9 protein do?
It uses CRISPR sequences to recognize and cut matching DNA.
What is the role of Cas1 and Cas2?
They acquire and integrate viral DNA into the CRISPR array.
What enzyme processes pre-crRNA?
RNase III, with the help of tracrRNA.
What forms the CRISPR-Cas9 complex?
crRNA, tracrRNA, and Cas9.
What is the purpose of the PAM sequence?
It enables Cas9 to recognize and bind the correct DNA target
What is the PAM sequence recognized by Cas9 from S. pyogenes?
5’ NGG 3’
Why is the PAM important for bacterial safety?
It helps Cas9 distinguish viral DNA from the bacterium’s own DNA.
What are the two small RNAs used by Cas9?
crRNA and tracrRNA.
What is single-guide RNA (sgRNA)?
A synthetic combination of crRNA and tracrRNA used to direct Cas9.
What are four common applications of CRISPR-Cas9?
1) Gene knockout, 2) Gene editing, 3) CRISPRi, 4) CRISPRa
What are some organism modifications possible with CRISPR-Cas9?
Biofuel-producing yeast, improved crops, malaria-resistant mosquitoes.
What must be included in CRISPR experiments to ensure accuracy?
Positive and negative controls to detect off-target effects.
What is DNA-free CRISPR-Cas9 editing?
Genome editing without inserting foreign DNA.
