The Techniques Involved in Genetic Engineering

In addition to the information in this presentation, you should also be familiar with the corresponding information found on pages in your textbook

Genetic Engineering Genetic engineering Altering the genetic code of a living organism in other words… Changing the DNA of a living thing on purpose

The Changes… Selective Breeding Inbreeding Hybridization Molecular manipulation Inducing mutations DNA splicing

Selective Breeding Inbreeding The continued breeding of individuals with similar characteristics While inbreeding does maintain the characteristics of the breed, it also makes genetic defects more common

Selective Breeding Hybridization The process of mating two organisms from different species to create a hybrid

Selective Breeding Hybridization In plants

Selective Breeding Hybridization In animals

Selective Breeding Hybridization In animals

Selective Breeding Hybridization In animals

Molecular Manipulation Inducing mutation Using artificial means (for example: radiation or drugs) to cause specific mutations in living organisms

Molecular Manipulation Inducing mutation Certain mutation causes extra chromosomes leading to bigger and stronger fruiting plants

Molecular Manipulation Inducing mutation Certain mutation causes oil-eating bacteria Used to clean up oil spills!

Molecular Manipulation DNA splicing Taking a segment of DNA from one organism and putting it into the DNA of another organism Let’s go through the process…

Molecular Manipulation DNA splicing Extracting the DNA Getting the DNA out of the cell and separating it from the other cell parts

Molecular Manipulation DNA splicing Cutting the DNA Whole DNA molecules are too large to be analyzed Scientists cut them into smaller pieces using restriction enzymes

More on Restriction Enzymes A restriction enzyme is a specialized enzyme that cuts the DNA molecule at a very specific sequence There are hundreds of restriction enzymes, each one cutting the DNA at a specific sequence Think of restriction enzymes like a lock and key: a restriction enzyme will cut a DNA sequence only it matches precisely

More on Restriction Enzymes EcoR I SmaI Cuts the DNA at the sequence CTTAAG, between the A and G Cuts the DNA at the sequence CCCGGG, between the C and G AA AA AGG G C CCTT TT T G C AA AA AGG G C CCTT TT T G C A A AA AG G G C C C TT TT T G C AGG G C CCT G C A T G C G CG C G C AGG G C CCT G C A T G C G CG C G C AG CT G C G C G G C C G C A TG C G C

Molecular Manipulation DNA splicing Pasting the DNA Using and enzyme called DNA ligase to attach segments of DNA

Molecular Manipulation Real world application:

Analyzing DNA Gel Electrophoresis DNA that has been cut with restriction enzymes is placed in wells at one end of a porous gel An electric voltage is applied to the gel, and the DNA which has a (-) charge moves away from the (-) charge and toward the (+) charge The smaller the DNA particle, the farther it is able to move through the porous gel This allows scientists to compare the DNA sequences from different individuals, or determine the relative sizes or particular genes

Analyzing DNA Gel Electrophoresis