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Improved sanitation systems Surgery with anesthesia Vaccines and antibiotics And the fourth will be Gene Therapy

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Page 1: Improved sanitation systems Surgery with anesthesia Vaccines and antibiotics And the fourth will be Gene Therapy
Page 2: Improved sanitation systems Surgery with anesthesia Vaccines and antibiotics And the fourth will be Gene Therapy

• Improved sanitation systems

• Surgery with anesthesia

• Vaccines and antibiotics

• And the fourth will be Gene Therapy

Page 3: Improved sanitation systems Surgery with anesthesia Vaccines and antibiotics And the fourth will be Gene Therapy

• The selective delivery of genes into a patients cells

create missing proteinsreplace defective disease causing genes

Over 4,000 conditions are caused by damage to a single gene, many others by several genes

Page 4: Improved sanitation systems Surgery with anesthesia Vaccines and antibiotics And the fourth will be Gene Therapy

Ex-vivo “outside the body”

adding blood cells with new DNA to the blood stream

but has a limited time span

Using bacteria like E.coli to produce billions of copies of a human gene

Using viruses to carry the gene to specific cells in the body

Page 5: Improved sanitation systems Surgery with anesthesia Vaccines and antibiotics And the fourth will be Gene Therapy

A cutting enzyme called a Restriction enzyme

It cuts foreign DNA that enter bacteria, e.g. Eco. R1

A circular DNA molecule from a bacteria called a Plasmid

The E. coli bacteria has dozens of different plasmids

A section of the human DNA containing the gene you need

An enzyme to join the bacterial DNA and human DNA called ligase

Page 6: Improved sanitation systems Surgery with anesthesia Vaccines and antibiotics And the fourth will be Gene Therapy

Found in many bacteria

A defense mechanism which cuts foreign DNA

The DNA is not cut randomly, but at specific sequences called

Recognition sequences

The restriction enzyme Eco.R1 found in strain C, E. coli bacteria

They don’t make straight cuts, but produce sticky ends

These sticky ends can rejoin by forming hydrogen bonds and the sugar-phosphates rejoining with the help of the enzyme ligase

The DNA produced by restriction enzymes cutting is called gDNA

We know of 200 different restriction enzymes

Page 7: Improved sanitation systems Surgery with anesthesia Vaccines and antibiotics And the fourth will be Gene Therapy

The Plasmid pSC101 was isolated from E. coli. It is useful for gene therapy because it has only one sequence of GATTC in its entire molecule

Plasmids can be used to replicate DNA segments of up to 4,000 base pairs in length

For longer length viruses must be used.

Page 8: Improved sanitation systems Surgery with anesthesia Vaccines and antibiotics And the fourth will be Gene Therapy

Using Bacterial Plasmid

Cut the Bacterial Plasmid using restriction enzyme called Eco R1

Page 9: Improved sanitation systems Surgery with anesthesia Vaccines and antibiotics And the fourth will be Gene Therapy
Page 10: Improved sanitation systems Surgery with anesthesia Vaccines and antibiotics And the fourth will be Gene Therapy

This produces a hole in the circular Plasmid DNA

•Eco. R1 only cuts at the sequence GAATTC

•This produces two identical ends

Page 11: Improved sanitation systems Surgery with anesthesia Vaccines and antibiotics And the fourth will be Gene Therapy

Also treat human DNA with Eco.R1 and you get a section of DNA containing the gene you want with two complementary ends as well!

Short sequence of DNA with sticky ends approaches a Plasmid.

Human DNA

Plasmid

Page 12: Improved sanitation systems Surgery with anesthesia Vaccines and antibiotics And the fourth will be Gene Therapy
Page 13: Improved sanitation systems Surgery with anesthesia Vaccines and antibiotics And the fourth will be Gene Therapy

Bacterial DNA

Human DNA

The newly completed piece of DNA is called Recombinant DNA

Page 14: Improved sanitation systems Surgery with anesthesia Vaccines and antibiotics And the fourth will be Gene Therapy

Gene cloning can now be used to produce millions of copies

Page 15: Improved sanitation systems Surgery with anesthesia Vaccines and antibiotics And the fourth will be Gene Therapy

A Plasmid with human DNA is put back into a E. coli

The bacteria expresses the DNA.

The bacteria then divides to produce millions of copies bacteria and human gene.

Page 16: Improved sanitation systems Surgery with anesthesia Vaccines and antibiotics And the fourth will be Gene Therapy

A Plasmid cut by a restriction enzyme

Segment of DNA approaches

Foreign DNA spliced into Plasmid by

DNA ligase joins phosphates and sugars

Plasmid enters bacterial cell

Page 17: Improved sanitation systems Surgery with anesthesia Vaccines and antibiotics And the fourth will be Gene Therapy

Viruses can be used to transfer large pieces of human DNA to a location in the Human body.

Viruses are made up of a molecule of nucleic acid and a protein coat.

Their nucleic acid codes for protein coats, replication, enzymes to break-in and out of particular cells.

You remove the part of the nucleic acid that does not code for the above functions and add foreign DNA.

The virus can then be put into the blood stream and it will enter the cell it is designed to attack and transfer its code into that cell.

Page 18: Improved sanitation systems Surgery with anesthesia Vaccines and antibiotics And the fourth will be Gene Therapy

Some current uses & trials of gene therapy•Introduction of genes for new blood vessels for clogged arteries

•Introduction of genes into the blood stream that interferes with the replication of HIV

•Human growth hormone for Dwarfism

•Insulin production

•Glowing mice

•Replacing the cytoplasm in eggs to produce healthier eggs

Page 19: Improved sanitation systems Surgery with anesthesia Vaccines and antibiotics And the fourth will be Gene Therapy

Injecting genes into the blood stream which are then carried to the target cells by viral carriers where they unload their genetic material.

This is then used by the body to produce proteins that fight the disease.

For the next decade gene therapy will only be used on somatic cells (only effect the patient and not their offspring)

You and bioethicists will have to decide the future!