Crispr cas9

CRISPR, CAS9, Genome Editing, ZFNS, TALENS, Spacer DNA, tracrRNA, crRNA, sgRNA, PAM, CRISPAR-CAS9, CAS GENES, Gene editing, gene silencing, gene knockout, CAS protein, enzyme, nuclease, restriction enzyme, CRISPR Array, Genetic Engineering, Applications of CRISPR, Advantages of CRISPR, LIMITATIONS OF CRISPR, DISADVANTAGES OF CRISPR, BENEFITS OF CRISPR, Future of CRISPR, CRISPR and Cancer, Ethical Issues.

1. CRISPR-CAS9 BY HASNAT TARIQ

2. GENOME EDITING Genome editing is a group of technologies that give scientists the ability to change an organism's DNA. These technologies allow genetic material to be added , removed , or altered at particular locations in the genome. A number of genome editing techniques have been developed such as : ZFNs (Zinc Finger Nucleases) TALENs (Transcription Activator Like Effector Nucleases) CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats)

3. CRISPR CRISPR are sections of genetic code containing short repetitions of base sequences followed by spacer DNA segments. It is a revolutionary technique that can modify any region of the genome of any species with high precision and accuracy without harming other genes . It was identified in a prokaryotic defence system.

4. Terms to understand Palindromic Sequences A  palindromic sequence  is a nucleic acid sequence on double-stranded DNA or RNA wherein reading 5' (five-prime) to 3' (three prime) forward on one strand matches the sequence reading 5' to 3' on the complementary strand with which it forms a double helix. 

5. Terms to understand ( Continue..) Spacer DNA Noncoding DNA that separates one gene from another is called spacer DNA. In bacteria, spacer DNA sequences are only a few nucleotides long. 

6. Terms to understand ( Continue..) crRNA Contains the guide RNA that locates the correct section of host DNA along with a region that binds to tracrRNA forming an active complex. tracrRNA Trans activating crisper RNA  (tracer RNA) is another important molecule that plays a critical role in the processing of pre-crRNA. It is a short RNA sequence and is complementary to the CRISPR repeat. It binds to crRNA and and forms an active complex.

7. Terms to understand ( Continue..) sgRNA Single guide RNA is a combination of tracrRNA and crRNA. PAM Protospacer adjacent motif (PAM) is a 2-6 base pair DNA sequence immediately following the DNA sequence targeted by the Cas9 nuclease in the CRISPR bacterial adaptive immune system.   PAM is a component of the invading virus or plasmid, but is not a component of the bacterial CRISPR locus.

8. CAS9 Cas9  (CRISPR  as sociated protein 9) is an   RNA-guided DNA endonuclease enzyme   associated with the CRISPR. It is associated with the CRISPR adaptive immunity system in  Streptococcus pyogenes , among other bacteria. It catalyzes site-specific cleavage of double stranded DNA.

9. CRISPR-CAS SYSTEM The CRISPR-Cas system is a naturally occurring, adaptive microbial immune system for defense against invading phages and other mobile genetic elements. It contains a cluster of CRISPR-associated ( Cas ) genes and its corresponding CRISPR array .  CRISPR arrays consist of repetitive sequences (direct repeats, referred to as repeats) interspaced by short stretches of nonrepetitive sequences (spacers) derived from short segments of foreign genetic material. 

10. CRISPR systems in prokaryotic immunity

11. CRISPR/Cas9 and Targeted Genome Editing

12. CRISPR/Cas9 and Targeted Genome Editing

13. CRISPR/Cas9 and Targeted Genome Editing

14. CRISPR/Cas9 and Targeted Genome Editing

15. CRISPR/Cas9 and Targeted Genome Editing

16. What can we do with CRISPR?

17. What can we do with CRISPR?

18. Applications of CRISPR

19. Advantages of CRISPR Target design simplicity Efficient Cheaper Multiplexed Mutations Quicker More accessible for researchers

20. Limitations of CRISPR Target sequences may be limited due to PAM sequences. Off target effects could be possible.

21. Future of CRISPR Human gene therapy Agriculture, crops, animals Screens for drug target ID Viral gene disruption Ecological vector control (Mosquito sterilization etc ) Synthetic biology ( Pathway engineering) Programmable RNA targeting

22. The First CRISPR Trial in Humans Will Target Cancer The doctors plan to use CRISPR to edit human T cells, which play a central role in the immune system, to target tumors.  For human CRISPR trial, doctors plan to extract blood cells from the patients and then edit the cells outside the body, an approach called ex vivo gene therapy.  Using CRISPR, the doctors will delete two specific genes from the T cells. One is a so-called “checkpoint” molecule (PD-1 ) that cancer cells exploit to halt immune system activity. The other is a receptor that T cells use to detect dangers, such as germs or sickly tissue. They’ll replace that receptor with an engineered one designed to direct T cells toward tumors.

23. Ethical Issues Balance of risks and benefit Ecological disequilibrium Regulations for consumers Application of CRISPR/Cas9 technique to human germline Genome editing for enhancement

24. References Futurism. (2018).  How CRISPR Works: The Future of Genetic Engineering and Designer Humans . [online] Available at: https://futurism.com/images/how-crispr-works-the-future-of-genetic-engineering Futurism. (2018).  The first American CRISPR trial in humans will target cancer . [online] Available at: https://futurism.com/first-american-human-crispr-trial-target-cancer