Flashcards in Gene editing Deck (8)
What are ZFNs?
Zinc finger domains that dimerise to cut DNA
What 2 ways do ZFNs cut DNA?
NHEJ- non-homologous end joining- short indels disrupt genes for knockout
HR if a template sequence is in introduced for knockins
Describe the first ZFN transgenic rat
Targeted immunoglobulin heavy chain μ locus (IgM)
Knockout to study the role of antibodies
What 2 components are needed for CRISPR?
A synthetic target-specific guide RNA (gRNA)
What is in the gRNA?
tracrRNA with a target-specific crRNA sequence and a ds region that guides CAS9 into position
What does CAS9 do?
Recognises and binds to a 3-9bp proto-spacer adjacent motif (PAM) and then unwinds the ds chromosomal DNA and the complementary region of the gRNA hybridises which triggers CAS9 to change in 3D structure and activates its nuclease activity to cut the DNA upstream of PAM
Describe gene editing in cattle
Knockout myostatin gene which inhibits muscle development using TALENS using injection into egg cytoplasm for larger cattle