GENETIC ENGINEERING

Report by: Jess Palo

Any process by which genetic material is changed in such a way as to make possible of the production of new substances or new functions.

Genetic Engineering

Prior 1950s◦ Term “gene” was used to stand for the unit by

which some genetic characteristics passed to generation.

1953◦ Englishc chemist Francis Crick & American

biologist James Watson created the DNA structure

Chemical Structure of Genes

Chemical Structure of Genes

Are very long chains/units made up of a combination of simple sugar and phosphate group.

DNA

Attached to this chains are the nitrogen base ( A, T, C, G)

CHONP

Chemical Structure of Genes

Each DNA has a pattern

CODONS (amino acids)

Arranged into particular sequence

protein

Is the process in which fragments of DNA from one or more different microorganism are combined to form rDNA (recombinant DNA) and are made to function within the cell of a host organism.

2 highly significant techniques:◦ Gene transfer

transferring the gene from one source to another subject.

◦ Gene therapy Correcting defective gene that are responsible for

disease development.

Gene Splicing

Gene Splicing

Plasmid - A circular form of DNA often used as a vector in genetic engineering.

Vector – an organism/ chemical that is used to transport a gene to the host cell.

Host cell – the cell into where the new gene is transplanted

Enzymes used:◦ Endonucleases – enzymes that cut DNA molecule at some given

location◦ Exonucleases – enzyme that removes one nitrogen base unit at

a time◦ Ligases – enzyme that join two DNA segments together

Gene Splicing

Although the concept of gene transfer is relatively simple, its execution presents considerable technical obstacles.

 American biochemist Paul Berg (1926-), often referred to as the “father of genetic engineering”. He developed a method for joining the DNA from two different

organisms, a monkey virus known as SV40 and a virus called lambda phage.

the American biochemists Stanley Cohen (1922-) at Stanford University, and Herbert Boyer (1936-) at the University of California and San Francisco, discovered an enzyme that greatly increased the efficiency of the Berg procedure. 

Gene Transfer

INSULIN◦ Produced by “Genetech”, first genetic engineering

company, founded by Robert Swanson and Herbert Boyer. Obtains a copy of insulin gene (can be from natural

source or manufactured) Inserting the insulin gene into the vector (using the

gene splicing process) The hybrid plasmid can now be inserted to the host

cell. ( this is the manufactured insulin that is injected to diabetic patients)

Gene Transfer

Human growth hormone◦ For children whose growth is insufficient bc of genetic

problems Interleukin-2

◦ For treatment of cancer Factor VIII

◦ Needed by hemophiliacs for blood clotting Erythropoietin

◦ For treatment of anemia Tumor necrosis factor

◦ For treatment of tumors Tissue plasminogen activator

◦ Use to dissolve blood clots

Other rDNA products

4 approaches◦ A normal gene inserted to compensate for the

defective gene.◦ Abnormal gene replaced with a normal one◦ Abnormal gene repaired through selective reverse

mutation◦ Change the regulation of gene pairs.

Gene Therapy

Gene Therapy

◦ A vector delivers the therapeutic gene into a patient’s target cell

◦ The target cells become infected with the viral vector

◦ The vector’s genetic material is inserted into the target cell

◦ Functional proteins are created from the therapeutic gene causing the cell to return to a normal state.

Gene Therapy

The first gene therapy was performed on September 14th 1990◦ Ashanti DeSilva was treated for SCID◦ Doctors removed her white blood cells, inserted

the missing gene into the WBC and then put them back into her blood stream

◦ It strengthened her immune system, but it only worked for a few months

Gene Therapy

◦ Genetic Engineering could increase genetic diversity, and produce more variant alleles which could also be crossed over and implanted into other species

◦ Another of genetic engineering is that diseases could be prevented by detecting people that are genetically prone to certain hereditary diseases, and preparing for the inevitable. As well as preventing disease, with genetic engineering infectious diseases can be treated by implanting genes that code for antiviral proteins specific to each antigen 

Advantages

◦ Animals and plants can be 'tailor made' to show desirable characteristics. Genes could also be manipulated in trees for example, to absorb more CO2 and reduce the threat of global warming. 

Advantages

◦ Nature is an extremely complex inter-related

chain consisting of many species linked in the food chain. Some scientists believe that introducing genetically modified genes may have an irreversible effect with consequences yet unknown. 

◦ Genetic engineering borderlines on many moral issues, particularly involving religion, which questions whether man has the right to manipulate the laws and course of nature. 

Disadvantages

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