An introduction of the new tech in genetic engineering

1. CRISPR CAS9
By SHAHD ALAKWAA
And The Story Behind CRISPR Babies

2. OUTLINES
• Introduction
• How Genes Are Edited ???
• CRISPR Cas9 System Use In Genome Editing
• How Does CRISPR Cas9 Work???
• CRISPR Babies
• Ethical Issues About CRISPR
• Implications Of Genome Editing
2

3. Why do we need genome editing?
• For research: to change the DNA in cells or organisms to
understand their biology and how they work.
• For biotechnology: in agriculture to genetically modify crops to
improve their yields and resistance to disease and drought, as well
as cattle that don’t have horns.
• To treat disease: to modify human blood cells to treat
leukaemia and AIDS. Also to treat other infections (such as MRSA)
and simple genetic conditions (such as muscular dystrophy).
3

4. 4

5. Introduction
DNA editing in general
▪ Genome editing with engineered
nucleases (GEEN) is a type of genetic
engineering in which DNA is inserted,
deleted or replaced in the genome of
a living organism using engineered
nucleases, or "molecular scissors“.
5

6. How does genome editing work?
•It uses a type of enzyme called an ‘engineered nuclease’ which cuts
the genome in a specific place.
•After cutting the DNA in a specific place, the cell will naturally repair
the cut.
•We can manipulate this repair process to make changes (or ‘edits’) to
the DNA in that location in the genome.
6

7. • Engineered Nucleases are made up of two parts:
7

8. Genome Editing Systems
•There are different types of engineered nuclease. They all contain a
Nuclease part to cut the DNA, and a DNA-targeting part to recognise
the DNA sequence they cut.
•They differ in how they recognise the DNA to cut:
• RNA-based: contain a short sequence of RNA that binds to the
target DNA.
• Protein-based: contain a protein that recognises and binds to the
target DNA.
8

9. What is CRISPR-Cas9 system?
• CRISPR ‘Clustered Regularly Interspaced Short Palindromic
Repeats’.
• Cas9 stands for CRISPR-associated protein 9, and is the nuclease part
that cuts the DNA.
• CRISPR-Cas9 is the most common, cheap and efficient system
used for genome editing.
9

10. 10
It is an RNA-based genome editing system
 Originally discovered in bacteria that use this system to destroy
invading viruses.
Cas9 enzyme from Streptococcus pyogenes, is the most well-
characterized and widely used Cas9 in genome engineering.

11. 11

12. 12

13. Timeline of Human genome editing
■ March 2015: Chinese researchers became the first to edit
genes in a human embryo
■ June 2016: He Jiankui launches a project to edit genes in
human embryos, with a goal of a live birth.
■ March 2017: He starts recruiting couples (each with an HIV-
positive father) for the experiment.
■ Early November 2018: gene-edited twin girls are reportedly
born, and a second pregnancy with a third gene-edited
embryo is established.
13

14. Timeline of Human genome editing
■ November-December 2018: China’s National Health
Commission orders an investigation into He’s work.
■ January 2019: He is censured by the Guangdong's health
ministry and fired from his university.
■ 18 March 2019: a World Health Organization committee will
meet to see the guidelines for human gene editing
■ August 2019: third gene-edited baby expected.
14

15. CRISPR BABIES
15

16. CRISPR babies
■ A Chinese biophysics researcher in Southern University of Science and
Technology, Dr. He Jiankui conducted a genome editing trial and the
result was revealed in November 2018: The First in the world “DNA -
edited” girl twin known as “Nana” and “Lulu”.
■ The aim of the experiment was to make the embryos resistant to
some strains of HIV
■ He stated that the two girls were born healthy with no abnormalities.
16

17. CRISPR babies
■ He’s work involved creating embryos from a healthy mother and a
HIV-positive father and applying the gene editing tool CRISPR-Cas9 to
those embryos to remove the CCR5 gene which allows HIV into cells.
■ He claimed that whole-genome sequencing of the newborns’ cord
blood showed that no other parts of the genome have been altered.
17

18. 18

19. 19

20. Ethical issues about crispr cas9
■ Due to the SMALL possibility of off-target effects and mosaicism
(when some cells carry the edit but others do not), safety is of
primary concern.
■ Researchers and ethicists agree that germline editing should NOT be
used for clinical reproductive purposes; the risk cannot be justified
by the potential benefit.
20

21. Ethical issues about CRISPR cas9
■ This technique is dangerous because of the spread of the new
changes among humans/animals.
■ Another point to worry about is that crispring can be
performed by even a talented high scholar if he/she's
completely aware of the procedure.
21

22. 22

23. How can genome editing be efficient to
human in the near future
■ Could have major implications for treating non-dividing
cells in the heart and liver – and could make people live
longer.
■ To fix genes TO CURE INCURABLE DISEASES
■ Sequencing genes to spot the site of any mutation.
■ To restore the sight of rats blinded by a condition which
also affects humans.
23

24. CRISPR super baby goals!
24

25. Sources:
o National Academies of Sciences, E., Medicine, Human Genome Editing: Science, Ethics, and
Governance. Washington, DC: The National Academies Press. 2017.
o Fuguo Jiang and Jennifer A. Doudna, CRISPR–Cas9 Structures and Mechanisms, Annual Review
of Biophysics, May 2017
o He Jiankui, the Human Genome Editing Conference, Hong Kong, 28 November 2018
o Julia Paoli, HIV Resistant Mutation, October 06, 2013
o Molecular Cell, DOI, 14 December 2018
o Shepherd, Christian; Wong, Sue-Lin; Kelland, Kate "Chinese scientist who gene-edited babies
fired by university“; 21 January 2019.
o Keiichiro Suzuki, Yuji Tsunekawa, In vivo genome editing via CRISPR-Cas9 mediated
homology-independent targeted integration, November 16, 2016
o The new SLENDR technique: Protein labeling in the developing brain by genome editing
o Max Planck Florida Institute for Neuroscience, The new SLENDR technique: Protein labeling in
the developing brain by genome editing, May 12, 2016
25

26. THANK YOU