UNIT 3 GENETICS: CRISPR

keep it crispy *finger guns*

a complex in bacteria that protected from viruses

where did crispr originate from

clustered regularly interspaced palindromic repeats

wha does crispr stand for

a nuclease protein paired with a strand of guide RNA that can cut and destroy target DNA

what is cas 9 and what is its function

a locus of bacterial DNA

what is crispr 

bacteria insert a part of the virus’s DNA into thier own genome and creat a CRISPR sequence, then they combine it with a cas 9 protein and target the virus the next time it enters the cell

Describe the normal crispr process in bacteria

the crisper sequences for each virus are separated by repeat spacers and then when they are transcribed into crRNA they are processed and split into individual sequences able to target specific viruses with cas9

how is crispr able to target multiple viruses

Protospacer adjacent motifs

what does pam stand for

sequences in the target virus genome which cas9 must recognize before it can cut, it prevents cas9 from cutting the bacteria’s crispr sequence because it does not have pam 

what are pams and what is their function 

crRNA and tracrRNA

what are the two components of guide RNA used by cas9

CRISPR RNA it is the strand complementary to the virus that cas9 matches to the virus genome

what does crRNA stand for and what is its function

trans-activating crRNA, attched to crRNA to help guide the cas9 

what does tracrRNA stand for and what is its function

nonhomologous end joining and homologous recombination

what are the two repair mechanisms that cells use to respond to cas9 cuts

nonhomologous end joining, a mechanism that reattaches the two cut ends of a chromosomal break and normally causes a random mutation resulting in loss of gene function 

what is NHEJ and what is its function 

homologous recombination, when a homologous donor like a sister chromatid or plasmid is used to repair the cut made by CAS9 and the gene retains function 

what is HR and what is its function 

gene therapy, agricultural advancement, defense against pathogens and viral genes, RNA targeting

what are some applications for Crispr-cas9 in the scientific world

crispy

“keep it _____”