Manipulating DNA The Techniques Involved in Genetic Engineering

Manipulating DNA The Techniques Involved in Genetic Engineering

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 Sma. I Eco. R I �Cuts the DNA at the sequence CTTAAG, between the A and G T C T T A A G C C �Cuts the DNA at the sequence CCCGGG, between the C and G A A T T C G G T C C C G G G C T C A G G G C C C G A G T C T T A A G C C A G A A T T C G G T C C C G G G C T C A G G G C C C G A G T C T T A A A G G C C A A T T C G G T C C C A G G G C T C C G A G

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

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