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 Protein transcripttranslation 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 gene 2. Restriction- Cutting 3. 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

Figure 12.1B E. coli bacterium Bacterial chromosome A plasmid is isolated. Gene of interest The plasmid is cut with an enzyme. Plasmid The cell’s DNA is isolated. The cell’s DNA is cut with the same enzyme. DNA Examples of gene use A cell with DNA containing the gene of interest Gene of interest The targeted fragment and plasmid DNA are combined. DNA ligase is added, which joins the two DNA molecules. Gene of interest Genes may be inserted into other organisms. The recombinant plasmid is taken up by a bacterium through transformation. Examples of protein use Harvested proteins may be used directly. The bacterium reproduces. Clone of cells Recombinant bacterium Recombinant DNA plasmid

Figure 12.1B_s1 E. coli bacterium Bacterial chromosome A plasmid is isolated. Gene of interest Plasmid The cell’s DNA is isolated. DNA A cell with DNA containing the gene of interest 1 2

Figure 12.1B_s2 E. coli bacterium Bacterial chromosome A plasmid is isolated. Gene of interest Plasmid The cell’s DNA is isolated. DNA A cell with DNA containing the gene of interest The plasmid is cut with an enzyme. The cell’s DNA is cut with the same enzyme. Gene of interest

Figure 12.1B_s3 E. coli bacterium Bacterial chromosome A plasmid is isolated. Gene of interest Plasmid The cell’s DNA is isolated. DNA A cell with DNA containing the gene of interest The plasmid is cut with an enzyme. The cell’s DNA is cut with the same enzyme. Gene of interest The targeted fragment and plasmid DNA are combined.

Figure 12.1B_s4 E. coli bacterium Bacterial chromosome A plasmid is isolated. Gene of interest Plasmid The cell’s DNA is isolated. DNA A cell with DNA containing the gene of interest The plasmid is cut with an enzyme. The cell’s DNA is cut with the same enzyme. Gene of interest The targeted fragment and plasmid DNA are combined. DNA ligase is added, which joins the two DNA molecules. Gene of interest Recombinant DNA plasmid

Figure 12.1B_s5 Gene of interest The recombinant plasmid is taken up by a bacterium through transformation. Recombinant bacterium Recombinant DNA plasmid 7

Figure 12.1B_s6 Gene of interest The recombinant plasmid is taken up by a bacterium through transformation. The bacterium reproduces. Clone of cells Recombinant bacterium Recombinant DNA plasmid 7 8

Figure 12.1B_s7 Gene of interest The recombinant plasmid is taken up by a bacterium through transformation. Harvested proteins may be used directly. The bacterium reproduces. Clone of cells Recombinant bacterium Recombinant DNA plasmid Genes may be inserted into other organisms

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

 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 ezymes Clipartguide.com

Restriction sites Plasmid Restriction site Donor DNA Restriction enzymes

Donor DNA Sticky Ends Plasmid

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 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

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 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

 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%

 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.

 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

 Transgenic plants and farm animals pest-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 transplantation avoid 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.