CRISPR

Question 1

What does CRISPR stand for?

Answer 1

Clustered Regulatory Interspaced Short Palindromic Repeats

Question 2

What are spacers?

Answer 2

Spacers lie in DNA and are not transcribed into messenger RNA. They are DNA sequences that separate short lengths of repeated DNA sequences that are transcribed. The repeated sequences are the CRISPRs.
Spacers separate CRISPRS.

Question 3

What are CRISPRs?

Answer 3

Specific regions in the genome that guide the cell to defend itself. Repeated DNA sequences that are transcribed to mRNA.

Question 4

What is Cas? What does Cas stand for?

Answer 4

Cas are genes near the cluster of CRISPR spacers. Cas refers to “CRISPR associated” proteins or genes. Cas genes code for proteins that cut up foreign or unwanted DNA.

Question 5

How does the CRISPR system work?

Answer 5

1. Adaption: Cell takes DNA from attacking virus, cuts it into short fragments and inserts them into the CRISPR sequence as spacers. When a new virus attacks the cell, a new spacer is made and added amongst the others. Spacers are lined in chronological order.
2. CRISPR spacers and repeats are transcribed to RNA and cut into fragments termed CRISPR RNAs. The relevant CRISPR RNAs then binds to the matching DNA sequence from the attacking virus. These CRISPR RNAs are referred to as “guide RNA and also crRNA”. The bound cr-RNA guides Cas proteins to cut up the phage DNA.

Question 6

What are guide RNA or crRNA?

Answer 6

These guide proteins to cut up phage DNA.

Question 7

Two main components of CRISPR-Cas9?

Answer 7

1. Cas9 enzyme- Cuts DNA

2. Snippet of RNA that guides these molecular scissors to the sequence that scientists want to cut