Biotechnology Exploring the source and exploitation of genetic alterations

Can we modify the genetic code of living things? (& should we?)

Means of genetic manipulation Increasing genetic variation  Mutation caused by mutagen (radiation or chemicals)  Use of drugs to produce polyploids Genetic engineering!!! (direct manipulation of an organism’s genes) Selective breeding  Of dissimilar individuals, called hybridization  Of similar individuals, called inbreeding

Genetic Engineering Also known as… Genetic modification or manipulation Recombinant DNA technology Gene splicing

Genetic Engineering Uses three main techniques or processes: Gene transfer Transformation Gene cloning

Tools of genetic engineering Restriction enzymes cut DNA at a specific place in the code Vectors & plasmids harvest DNA for cloning

How’s it done? As easy as 1, 2, 3… Rabbit DNA + Crab DNA = Crabbit

How to genetically engineer DNA 1. Isolate the gene sequence you want with a restriction enzyme (the cut leaves “sticky ends”) 2. Cut out sequence from the plasmid with the same restriction enzyme

How to genetically engineer DNA

Complementary sticky ends result when the same restriction enzyme is used to cut both the source DNA and the plasmid 3.Complementary sticky ends splice together

How to genetically engineer DNA 4. Plasmid is taken up by bacterium 5. Bacterium then has to incorporate the new DNA with its own. This is called transformation.transformation 6. Bacterium in now called a transgenic organism & becomes a cloning vector, making copies of the recombinant DNA transgenic

Transformation Genetic material is changed into another form by combining original DNA with another form of DNA, resulting in a new “strain” of DNA that has characteristics of both original versions.

Applications Recombinant DNA technology to produce transgenic organisms (organisms with other organisms’ genes) that help make better medicines, treatments, and supplements

Problem… How would you apply recombinant technology to make a vaccine? Hint: How do vaccines work? What does your immune system use to recognize foreign cells? Can your immune system be “tricked” into thinking it is infected with a virus?

Applications Gene therapy uses recombinant DNA technology to replace an absent or faulty gene with a normal, working gene Try your hand at gene therapy – click here

Polymerase chain reaction (PCR) copies DNA Gel electrophoresis makes a picture of DNA called a DNA fingerprint Other tools of genetic engineering

How to make a DNA fingerprint 1. Small amounts of DNA are extracted from blood, saliva, hair, urine, etc (Click here for Virtual DNA extraction Lab)Click here for Virtual DNA extraction Lab 2. If the amount of DNA is too small, the polymerase chain reaction, or PCR, can be used to increase the quantity of DNA (Click here for Virtual PCR lab)Click here for Virtual PCR lab

How to make a DNA fingerprint 3. DNA is cut into fragments of specific sizes by restriction enzymes 4. DNA is put in a slab of gel and an electrical current moves DNA to the + electrode (Click here for Virtual electrophoresis lab)Click here for Virtual electrophoresis lab  Bigger pieces move more slowly & travel shorter distances

How to make a DNA fingerprint 5. The banding pattern in the gel is analyzed

Applications DNA fingerprinting identifies differences between individuals’ genetic makeup to establish identity or relationships

Stem cells have the ability to develop into different cell types  What is a stem cell? What is a stem cell?  Types of stem cells Types of stem cells Embryonic stem cells Click here for helpful animation Somatic cell nuclear transfer Click here for Virtual Cloning Lab Other tools of genetic engineering

Applications Gene cloning enables rapid, large-scale production of useful genes, cells, tissues Watch Nova scienceNow: Stem Cells (click here)click here

Is there a need for a cure? Should “broken” genes be fixed?