DNA Manipulation Flashcards
CRISPR
Clustered regularly interspaced palindromic repeats. This is a prokaryotic viral defense system.
Usage of CRISPR in DNA manipulation
technology enables scientists to edit parts of the genome by removing, adding or altering sections of the DNA sequence.
CRISPR is a special kind of DNA found in bacteria, which use it to combat viral infections.
guide RNA
crRNA joined to the tracrRNA
complementary to target DNA and identifies it
Steps involved in editing a genome using CRISPR Cas 9
- Complex consisitng of CrRNA or sgRNA and Cas protein is created. this sequences is complementary to the target DNA seq
- using gRNA, Cas9 identifies corresponding DNA sequence within the genome and cuts both strands of DNA
- a new piece of DNA may be inserted ir sections of DNA may be removed
- cell detects and repairs broken strands of DNA
Cas 9
a protein complex that binds with the crispr enzyme
tracrRNA
trans-activating crRNA that binds to cRNA and keep it in place
crRNA
sequence of RNA complementary to the target DNA
What are CRISPRs
Prokaryotic endonucleases that cleave unwanted bacteriophage DNA.
Small guide RNA (sgRNA)
a nucleotide sequence that guides CRISPR to a specific genome locus. It in theory binds to the unique site in the genome
What are the 4 components of the CRISPR Cas molecule
- Cas9Enzyme
- crRNA
- tracrRNA
- gRNA
PAM sequence
Short DNA sequence that follows the DNA region targeted for cleavage by the CRISPR system, such as CRISPR-Cas9
Palindromic DNA sequence
Same when read from 5’ to 3’ one one strand and 3’ to 5’ on the other, complemtary strand
Ethics involving CRISPR
Is it ethical to edit out alleles in human population?
Is there a negative from removing these traits from the gene pool?
Long term effects of altering DNA in humans
Uses of CRISPR
The genomes of organisms could be manipulated to confer desirable characteristics in plants and animals
to improve crop yield and quality in agriculture
to combat diseases by altering bacteria and viruses
to bypass genetically inherited disorders by correcting faulty genes.
Why are PAM sequences important
distinguishes bacterial self from non-self DNA, thereby preventing the CRISPR locus from being targeted and destroyed by the CRISPR-associated nuclease.
