What we can do with genes Genetic Engineering What we can do with genes

Selective Breeding Humans select animals or plants with desirable (beneficial) traits and breed them This ensures that many of the offspring will have desirable traits from both parents This is how we have so many breeds of dogs and cats! This is also how we have certain fruits and vegetables with certain traits Does NOT involve actually changing DNA!

What is Genetic Engineering? Technology that humans use to alter DNA or study DNA Examples: DNA Fingerprinting (Gel Electrophoresis) Used in paternity testing Used as evidence in criminal cases DNA Recombination Inserting a gene into bacterial DNA Bacteria will then construct the protein coded for in that DNA

Restriction Enzymes Special enzymes that recognize certain DNA bases and then actually cut (splice) the DNA at that location Used in DNA Fingerprinting and DNA Recombination EXAMPLE: EcoRI recognizes GAATTC Will cut at this spot between the G and A Creates STICKY ENDS (single strands of DNA) that can bind to new DNA

EcoRI- Commonly used restriction enzyme

Restriction Enzyme Animations! Let’s See! Let’s See Again!

Types of Genetic Engineering Gel Electrophoresis Separates DNA into different banding patterns based on NUMBER OF BASES IN EACH CUT STRAND DNA is cut up using a restriction enzyme This leaves DNA strands of different sizes CHARGE OF DNA DNA is negatively (-) charged, so it will move towards a positive charge DNA separates due to opposite charge at one end of chamber and how heavy it is Makes a “finger-print” Parents will have similar banding to their children and vice-versa

Gel Electrophoresis How-to http://www.youtube.com/watch?v=RNQr7y58QAo&feature=related

Who’s the father?

Types of Genetic Engineering Recombinant DNA Technology Inserting gene from one organism into a circular piece of bacterial DNA called a plasmid http://www.youtube.com/watch?v=AEINuCL-5wc&feature=related

Steps for causing bacteria to make human insulin by Recombinant technology: Cut out insulin gene from human DNA using a restriction enzyme Cut open bacterial plasmid using same restriction enzyme Combine cut plasmids with many copies of human gene Several plasmids will “accept” human gene These plasmids now have the ability to make human insulin

Diagram of Recombinant DNA

Benefits of Genetic Engineering Making large amounts of a human protein, such as insulin Finding cures by altering DNA DNA Fingerprinting has helped us to see how similar certain orgs. are Alter DNA in plants to make them resistant to certain diseases Paternity tests! Let’s See!