biotechnology a. genetic engineering, also known as recombinant dna technology, means altering the...
TRANSCRIPT
BIOTECHNOLOGY
A. Genetic engineering, also known as recombinant DNA technology, means altering the genes in a living organism to produce a Genetically Modified Organism (GMO) with a new genotype.
B. Various kinds of genetic modification are possible: 1.inserting a foreign gene from
one species into another, forming a transgenic organism
2.altering an existing gene so that its product is changed
3.changing gene expression so that it is translated more often or not at all.
Humans are made up of trillions of cells
Each cell:
•46 human chromosomes
•2 metres of DNA
•3 billion DNA subunits (A,T,G,C)
•Approximately 22,000 genes
DNA RNA Proteintranscript translation
replication
genotype phenotype
A. It allows genes from one organism to be inserted into a cell of a different organism of a different species.
• Examples:– Human genes can be inserted into a
bacterium– Human genes can be inserted into cells
from other animals– Bacterium genes can be inserted into
plant cells
1. Isolation-Isolate the gene2. Restriction- Cutting3. Transformation - Insert it in a host using
a vector and produce as many copies of the host as possible
4. Expression-Separate and purify the product of the gene
E. coli bacterium
Bacterialchromosome
A plasmidis isolated.
Gene ofinterest
The plasmid is cutwith an enzyme.
Plasmid
The cell’s DNAis isolated.
The cell’s DNA is cutwith the same enzyme.
DNA
Examples of gene use
A cell with DNAcontaining the geneof interest
Geneof interest
The targeted fragmentand plasmid DNAare combined.
DNA ligase is added,which joins the twoDNA molecules.
Geneof interest
Genes may be insertedinto other organisms.
The recombinant plasmidis taken up by a bacteriumthrough transformation.
Examples of protein use
Harvestedproteinsmay beuseddirectly.
The bacteriumreproduces.
Cloneof cells
Recombinantbacterium
RecombinantDNAplasmid
1
3
5
4
2
6
7
9
8
E. colibacterium
Bacterialchromosome
A plasmidis isolated.
Gene ofinterest
Plasmid
The cell’s DNAis isolated.
DNA
A cell with DNAcontaining the geneof interest
12
E. colibacterium
Bacterialchromosome
A plasmidis isolated.
Gene ofinterest
Plasmid
The cell’s DNAis isolated.
DNA
A cell with DNAcontaining the geneof interest
1
3
2
4
The plasmid is cutwith an enzyme.
The cell’s DNA is cutwith the same enzyme.
Geneof interest
E. colibacterium
Bacterialchromosome
A plasmidis isolated.
Gene ofinterest
Plasmid
The cell’s DNAis isolated.
DNA
A cell with DNAcontaining the geneof interest
1
3
2
4
5
The plasmid is cutwith an enzyme.
The cell’s DNA is cutwith the same enzyme.
Geneof interest
The targeted fragmentand plasmid DNAare combined.
E. colibacterium
Bacterialchromosome
A plasmidis isolated.
Gene ofinterest
Plasmid
The cell’s DNAis isolated.
DNA
A cell with DNAcontaining the geneof interest
1
3
2
4
5
6
The plasmid is cutwith an enzyme.
The cell’s DNA is cutwith the same enzyme.
Geneof interest
The targeted fragmentand plasmid DNAare combined.
DNA ligase is added,which joins the twoDNA molecules.
Geneof interest
RecombinantDNAplasmid
Geneof interest
The recombinant plasmidis taken up by a bacteriumthrough transformation.
Recombinantbacterium
RecombinantDNAplasmid
7
Geneof interest
The recombinant plasmidis taken up by a bacteriumthrough transformation.
The bacteriumreproduces.
Cloneof cells
Recombinantbacterium
RecombinantDNAplasmid
7
8
Geneof interest
The recombinant plasmidis taken up by a bacteriumthrough transformation.
Harvestedproteinsmay beuseddirectly.
The bacteriumreproduces.
Cloneof cells
Recombinantbacterium
RecombinantDNAplasmid
Genes may be insertedinto other organisms.
9
7
8
Donor DNA
Genetic probe
(a) Isolation of a specific gene from donor e.g. human
• Cells broken open
• Genetic probe added
• Reveals position of the gene of interest
Position of gene of interest
Bacterial cell
Plasmid
(b) Isolation of plasmid from a bacterial cell
www.sci.sdsu.edu
Restriction enzymes (also called endonuclease) act as molecular scissors and cut DNA at specific sites called restriction sites
This makes a staggered cut with sticky ends ex: EcoRI
Restriction site
Restriction site
Restriction ezymes
Clipartguide.com
Restriction sites
Plasmid
Restriction site Restriction siteDonor DNA
Restriction enzymes
Donor DNA
Sticky EndsPlasmid
Enzyme DNA ligase bonds sticky ends together
Donor DNA with
sticky ends
Plasmid DNA with sticky ends
A. Vector – molecule of DNA which is used to carry a foreign gene into a host cell◦ Most common vectors are bacteria and viruses
B. A vector has to have certain properties: 1. It is big enough to hold the gene we
want 2. It is circular (or more accurately a
closed loop), so that it is less likely to be broken down
3. It contains control sequences, such as a transcription promoter, so that the gene will be replicated or expressed.
4. It contain marker genes, so that cells containing the vector can be identified
Plasmid DNA
Donor DNA
Enzyme DNA Ligase bonds sticky ends together
Next slide for animation
www.gch.ulaval.ca
Recombinant DNA
D. Recombinant DNA introduced into bacterial cell
Bacterial chromosome
Bacterial cell
Recombinant DNA
Bacterial cell reproduces by Binary Fisson
• Bacterial cell produces the polypeptide
• Coded for by the donor DNA
Donor DNA
Plasmid
1. Cut with restriction enzymes
Donor DNA
Sticky Ends
2. Ligase bonds sticky ends together
Recombinant DNA
www.encarta.msn.com
Genetically Engineered
Products
Insulin regulates the blood sugar level.
The gene for human insulin is inserted into yeast or bacteria, from which large quantities of the human insulin are manufactured
Production of humulin
https://www2.vaxserve.com/ index.cfm?event=get...
Undernourished people in poorer countries may have blindness caused by a lack of vitamin A
Contains beta-carotene, which forms Vitamin A
http://www.healingdaily.com/detoxification-diet/rBGH.jpg
rBGH is a genetically engineered version of a hormone, which is found in the pituitary gland of cows and controls milk production
rBGH can increase cows’ milk production by as much as 20-30%
http://simple.wikipedia.org/wiki/Image:Milk_glass.jpg
Elastic, light weight fiber 5 times stronger than steel
One method involves inserting the gene from a weaving spider into a fertilized goat egg. The resultant “spider-goat” produces milk that can be manufactured into strong fibers.
http://www.chm.bris.ac.uk/motm/spider/goat.jpg
To make flak jackets, rope, textiles, sutures, artificial tendons, and bandages for burn victims
Genes that make jellyfish glow are inserted into other organisms
The organism glows under UV light
Bt is a bacterial toxin that is toxic to some insects. In the lab, the gene that produces the toxic effect is inserted into the DNA of plants
Bt crops produce an insecticide protein thousands of times more powerful than the chemical spray insecticides
Can resist infection by an insect European corn borer
Genetically modified corn
www.farmbureaulaporteco.org
Transgenic plants and farm animalspest-resistant (reduce use of pesticides),increase yield
Increase storage time e.g. green tomato
tomato with beef genes
Clonal propagation: a source of tissue or organ for transplantationavoid all problems of immunoincompatibility.
Gene therapy:Artificially replace the disease-causing gene with a normal allele.The normal allele can be carried by a virus vector to the target tissues.e.g. treatment of cystic fibrosis
Production of pharmaceuticals for treatment of diseases e.g. human insulin, interferons
Production of pharmaceuticals for disease prevention e.g. vaccine (hepatitis B vaccine)
Use of GM microorganisms to make stone-wash jeans
Use of GM microorganisms to produce enzymes e.g. detergents
GM E. coli possesses gene to break down cellulose, speeding up recycling of the most abundant biomass on earth
GM microorganisms with enhanced ability to break down environmental pollutants
Dangerous pathogens formed in the course
New tools for militarists and terrorists Triggering of catastrophic ecological
imbalance Moral problems in the use of GM
techniques in man e.g. germ cell gene therapy
Unknown effect of GM food on men
Main concerns are in Genetically Modified Foods.
Effects on Food Chains of genetically modified plants and animals.
Also conflicts in relation to human cloning and stem cell research.