Mediated Genomic Editing Techniques Used By Bacteria And...

Crispr-Cas9 Mediated Genomic Editing Techniques In Animal Cells Sarcinella, Cody 705, Review Paper Introduction Clustered regulatory interspaced short palindromic repeats (CRISPR) and CRISPR associated protein 9 (Cas9) are an immune response evolved by bacteria and archea as an adaptive defense mechanism to invading DNA. (4) The CRISPR Cas9 system relies on the uptake of invading DNA fragments that are then inserted into CRISPR loci. (4) In the CRISPR loci, repeats are separated by nucleotide spacers which match and or composed of invading DNA.(4) New spacer DNA is incorporated by Cas1 and Cas2.(4) The CRISPR spacer loci then transcribe into short CRISPR RNAs (crRNA) which anneal to foreign nucleic acids in conjunction with complementary binding trans-activating cr RNA(tracrRNA) to form a duplex which is then cleaved to provide a guiding RNA cr/tracr RNA hybrid.(4) the RNA hybrid acts as a guiding mechanism for Cas9 by complementary binding to the invading nucleotides.(4) Cas9 is an endonuclease that can cause a double stranded cleave in DNA(4) Cas9 guided with sgRNA then cleaves the foreign D NA resulting in double stranded breaks effectively disrupting and thereby removing a gene.(1)(2)(3)(4) After a ds break occurs cellular machinery attempts to fix the break with non homologous end joining in which cellular systems effectively sutures the broken ends of the DNA by recombining the remaining ends of DNA to once again produce a continuous strand.(4) This