1. Introducing Gene Therapy
Session 1.14
Unit 1: Lifestyle, Transport, Genes and Health
Topic 2: Genes and Health
Introducing Gene Therapy
Introduction
Germ-line gene therapy
Somatic gene therapy
Techniques used in Gene therapy
Genetic screening
Social and Ethical Issues of Genetic Screening
AS Edexcel Biology Xavier DANIEL, Ph.D.

2. Introducing Gene Therapy
Session 1.14
Unit 1: Lifestyle, Transport, Genes and Health
Topic 2: Genes and Health
Introducing Gene Therapy
Introduction
Germ-line gene therapy
Somatic gene therapy
Techniques used in Gene therapy
Genetic screening
Social and Ethical Issues of Genetic Screening
AS Edexcel Biology Xavier DANIEL, Ph.D.

3. Genetic modification = Transformation = Genetic engineering
Introduction
Genetic modification = Transformation = Genetic engineering
Introducing extra genes into organisms
Creation of new combinations of DNA: Recombinant DNA technology
Bacteria and yeast: in plasmids or chromosome
Plant and animals: in chromosomes, mitochondria or chloroplasts
AS Edexcel Biology Xavier DANIEL, Ph.D.

4. Introduction
AS Edexcel Biology Xavier DANIEL, Ph.D.

5. Efficiency may be Introduction
Genetic disease: a gene is malfunctioning
Solution = replace the abnormal gene by the normal gene
Providing the correct gene to overcome genetic disease = Gene therapy
Efficiency may be
Transient
Supply affected person with
normal gene periodically
Or with the proteic product of the gene
Permanent
Supply affected person with
normal gene once
Gene was not inserted into patient’s genome
Gene was inserted into patient’s genome
AS Edexcel Biology Xavier DANIEL, Ph.D.

6. Several approaches to gene therapy:
Introduction
Several approaches to gene therapy:
Inserting a normal gene to replace an abnormal gene.
Inactivating, or “knocking out,” a mutated gene that is functioning improperly.
Introducing a new gene into the body to help fight a disease.
AS Edexcel Biology Xavier DANIEL, Ph.D.

7. STEPS IN GENE THERAPY: 1. Identification of the defective gene.
Introduction
STEPS IN GENE THERAPY:
1. Identification of the defective gene.
2. Cloning of normal healthy gene.
3. Identification of target cell / tissue / organ.
4. Insertion of the normal functional gene into the host DNA.
AS Edexcel Biology Xavier DANIEL, Ph.D.

8. Introduction of FUNCTIONAL GENES into appropriate cells
Transferred gene (TRANSGENE) encodes & produces proteins
The Proteins encoded by Transgene corrects the disorder
AS Edexcel Biology Xavier DANIEL, Ph.D.

9. TYPES OF GENE THERAPY: 1. SOMATIC CELL THERAPY 2. GERM LINE THERAPY
Introduction
TYPES OF GENE THERAPY:
1. SOMATIC CELL THERAPY
2. GERM LINE THERAPY
Target cells = somatic cells
Target cells = sex cells (gametes)
AS Edexcel Biology Xavier DANIEL, Ph.D.

10. Introducing Gene Therapy
Session 1.14
Unit 1: Lifestyle, Transport, Genes and Health
Topic 2: Genes and Health
Introducing Gene Therapy
Introduction
Germ-line gene therapy
Somatic gene therapy
Techniques used in Gene therapy
Genetic screening
Social and Ethical Issues of Genetic Screening
AS Edexcel Biology Xavier DANIEL, Ph.D.

11. Germ-line therapy
AS Edexcel Biology Xavier DANIEL, Ph.D.

12. Somatic Cell Nuclear Transfer
Germ-line therapy
SCNT
Somatic Cell Nuclear Transfer
AS Edexcel Biology Xavier DANIEL, Ph.D.

13. Introducing Gene Therapy
Session 1.14
Unit 1: Lifestyle, Transport, Genes and Health
Topic 2: Genes and Health
Introducing Gene Therapy
Introduction
Germ-line gene therapy
Somatic gene therapy
Techniques used in Gene therapy
Genetic screening
Social and Ethical Issues of Genetic Screening
AS Edexcel Biology Xavier DANIEL, Ph.D.

14. Somatic therapy In vivo gene therapy Ex vivo gene therapy
AS Edexcel Biology Xavier DANIEL, Ph.D.

15. Somatic therapy In vivo gene therapy
AS Edexcel Biology Xavier DANIEL, Ph.D.

16. Somatic therapy Ex vivo gene therapy
AS Edexcel Biology Xavier DANIEL, Ph.D.

17. epithelial cells in lungs
Somatic therapy
Cystic fibrosis
In vivo gene therapy
Use of Liposomes
Target =
epithelial cells in lungs
Transient effect
(Epithelial cells are renewed all the time)
Treatment must be
repeated regularly
AS Edexcel Biology Xavier DANIEL, Ph.D.

18. Introducing Gene Therapy
Session 1.14
Unit 1: Lifestyle, Transport, Genes and Health
Topic 2: Genes and Health
Introducing Gene Therapy
Introduction
Germ-line therapy
Somatic therapy
Techniques used in Gene therapy
Genetic screening
Social and Ethical Issues of Genetic Screening
AS Edexcel Biology Xavier DANIEL, Ph.D.

19. Techniques used in Gene therapy
In molecular biology in general
AS Edexcel Biology Xavier DANIEL, Ph.D.

20. Techniques used in Gene therapy
Separating DNA fragments according to their sizes with Gel electrophoresis
Gel made of Agarose / Polyacrylamide
Gel
Making the gel
Gel in tank
Loading
sample
in well
AS Edexcel Biology Xavier DANIEL, Ph.D.

21. Techniques used in Gene therapy
Separating DNA fragments according to their sizes with Gel electrophoresis
Running the electrophoresis
DNA negatively charged
Attracted by positive electrode
Gel = sieve
Smaller faster
Bigger slower
AS Edexcel Biology Xavier DANIEL, Ph.D.

22. Techniques used in Gene therapy
Separating DNA fragments according to their sizes with Gel electrophoresis
AS Edexcel Biology Xavier DANIEL, Ph.D.

23. Techniques used in Gene therapy
Separating DNA fragments according to their sizes with Gel electrophoresis
Visualizing the results
AS Edexcel Biology Xavier DANIEL, Ph.D.

24. Techniques used in Gene therapy
Separating DNA fragments according to their sizes with Gel electrophoresis
Visualizing the results
Molecular weight markers
Ladder
Estimation size DNA bands
AS Edexcel Biology Xavier DANIEL, Ph.D.

25. Techniques used in Gene therapy
Detecting specific DNA fragments with Southern Blotting
transfers
AS Edexcel Biology Xavier DANIEL, Ph.D.

26. Techniques used in Gene therapy
Detecting specific DNA fragments with Southern Blotting
AS Edexcel Biology Xavier DANIEL, Ph.D.

27. Techniques used in Gene therapy
Comparing two organisms with Southern Blotting
AS Edexcel Biology Xavier DANIEL, Ph.D.

28. Introducing Gene Therapy
Session 1.14
Unit 1: Lifestyle, Transport, Genes and Health
Topic 2: Genes and Health
Introducing Gene Therapy
Introduction
Germ-line therapy
Somatic therapy
Techniques used in Gene therapy
Genetic screening
Social and Ethical Issues of Genetic Screening
AS Edexcel Biology Xavier DANIEL, Ph.D.

29. Human Genome Project: sequence the whole human genome 1990 to 2000
Genetic screening
Human Genome Project: sequence the whole human genome
1990 to 2000
From first base pair of chromosome 1 to last base pair of sex chromosomes
Location and sequence of all genes known
Including genes responsible for genetic diseases
Screening for mutated genes responsible for genetic diseases
Know if individuals are normal, carriers, affected
1. Carriers may be treated before disease appear
2. Couple of carriers may assess the probability of having affected children
3. Couple of carriers may wish to screen the embryos in IVF
AS Edexcel Biology Xavier DANIEL, Ph.D.

30. Genetic screening
AS Edexcel Biology Xavier DANIEL, Ph.D.

31. Screening of IVF-produced embryos
Genetic screening
Screening of IVF-produced embryos
e.g. Down Syndrome
One extra chromosome 21
Southern blotting
Detection of mutated genes
e.g. Cystic Fibrosis
AS Edexcel Biology Xavier DANIEL, Ph.D.

32. Screening of “normally produced” embryos
Genetic screening
Screening of “normally produced” embryos
AS Edexcel Biology Xavier DANIEL, Ph.D.

33. Genetic screening Southern blotting
AS Edexcel Biology Xavier DANIEL, Ph.D.

34. Introducing Gene Therapy
Session 1.14
Unit 1: Lifestyle, Transport, Genes and Health
Topic 2: Genes and Health
Introducing Gene Therapy
Introduction
Germ-line therapy
Somatic therapy
Techniques used in Gene therapy
Genetic screening
Social and Ethical Issues of Genetic Screening
AS Edexcel Biology Xavier DANIEL, Ph.D.

35. Social and Ethical Issues of Genetic Screening
What is right?
What is wrong?
AS Edexcel Biology Xavier DANIEL, Ph.D.

36. Social and Ethical Issues of Genetic Screening
What is right?
What is wrong?
AS Edexcel Biology Xavier DANIEL, Ph.D.