The document summarizes the CRISPR-Cas system. It discusses how CRISPR-Cas provides adaptive immunity in bacteria and archaea by integrating short DNA sequences from invading viruses and plasmids between repeated DNA sequences in the host's CRISPR array. It then describes the key components of the CRISPR-Cas system including the CRISPR array, cas genes, and how the system acquires spacers and functions through different steps of biogenesis and interference to target invading genetic elements. Finally, it discusses some potential applications and limitations of using the CRISPR-Cas system for genome editing in areas like genetic diseases, cancer, and HIV.

1. CRISPR-Cas system
CRISPR-Cas
Presentationby:
Rekha Sansanwal
Umang Ahlawat

2. Genome Editing Technologies Exploit
Endogenous DNA Repair Machinery

3. Introduction
RNA-mediated adaptive immune systems protect bacteria
and archaea from invading mobile genetic elements
Bacteria
50%
Archaea (90%)

4. History

5. Components of CRISPR/Cas Systems
CRISPR
ARRAY
CAS
gene
CRISPR-
CAS
SYSTEM

6. CRISPR ARRAY
• 23-47bpin length
• Some arepallindromicREPEATS
• 72bp or may be small
• Conform sequence specific immunity
• Phage or plasmid derived
SPACERS
• AT rich sequence of about 200-500bp
in length
• Consist of promoter necessary for
transcription of CRISPR array
LEADER

7. Cas gene
Encodes CAS
proteins
Provide
diversityto
CRISPR Cas
system
Provides enzymatic machinery
required for acquisition of new
spacers from targeting or invading
element

8. Types of CRISPR- Cas system

9. CRISPR-
cas
system
Acquisition
of spacers
Biogenesis
and assembly
crRNPs
Interference
Steps in CRISPR Cas action

11. Diversity of CRISPR-cas system
Oost et al., 2014

12. Acquisition of spacers
Jackson et al., 2017

13. Biogenesis of crRNAS
Oost et al., 2014

14. Interference

15. Contd.

16. Design principle of a CRISPR/Cas9 expression
vector for construction of libraries
Heintze et al., 2013

17. Lead prospectus of CRISPR-Cas system
Genetic disease: Genetic retinal
disease by replacing dysfunctional
protein in photoreceptor cell (Flynn
et al., 2015).
Viral disease: HPV strain control by
inactivation of viral E7 gene (Liu et
al.,2015).
Cancer: Deletion of NANOG and
NANOGP8 in DU 145 prostate
cancer cell (Kamawaura et al.,
2015).
Cardiovascular disease:
Introduction of SERCA2a and
S100a1 gene. (Rincon et al., 2015
HIV: deletion of CCR 5 and expression
of CAR (Zhen et al., 2015).

18. Failure of CRISPR-CAS system
Stern et al., 2010

19. Significance of CRISPR-Cas system
• Acts as endo-
nucleases and
make site specific
cuts
Cas9
• Combination of
crRNA and tracer
RNA
gRNA
• Gene insertion and
deletion can be
possible from
prokaryotesto
eukaryotes
Genome
editing

20. THANK YOU