GENETIC ENGINEERING

SELECTIVE BREEDING:

SELECTIVE BREEDING: Allow only those with desired traits to reproduce After many generations, only desired traits will be in individuals Ex: Dogs, Cows

Sometimes favorable mutations arise (Ex: Missing Growth Inhibiting gene in Belgian Blue Cows) BELGIAN BLUE VIDEO

INBREEDING: The continued breeding of individuals with similar traits Pros: Have individuals with desired traits Cons: Little genetic diversity (Increase chance of genetic disease) Ex: Labs & Hips

WAYS TO INCREASE VARIATION: Use chemicals/radiation to create mutations (new genes) Ex: Create bacteria that can eat oil Culture these ones

How to Create Bigger, Better Plants:

HYBRIDIZATION Crossing 2 dissimilar individuals to create a blend of the 2 (must be closely related, especially in animals) Most Animal Hybrids are sterile (Ex: Mules & Ligers) Liger Video Top 10 Hybrid Examples

Steps of DNA GEL ELECTROPHORESIS

Extract DNA using chemicals

2. Cut DNA with Restriction Enzymes (they cut DNA at a specific sequence)

Base sequences in MOST genes are similar with all humans. The “junk” DNA between genes, however, is unique for an individual. Because everyone’s DNA is different between genes, restriction enzymes will cut everybody’s DNA at DIFFERENT places

Place sample of DNA on electrophoresis gel & run an electric current through it. Since DNA has neg. charge, it goes to pos. end Bigger pieces of DNA move more slowly than smaller pieces The pattern formed is unique to an individual Pattern formed is called “Banding Pattern”

GEL ELECTROPHORESIS & DNA FINGERPRINGTING Suspect B committed crime

½ of banding patterns will match mom, ½ will match dad Man 1 is the father

Gel Electrophoresis Animation

PCR (Polymerase Chain Reaction) Used to copy all or part of DNA PCR is used to take a small sample of DNA & make that sample large enough to be usable in a lab.

STEPS: 1. Make PRIMERS – short sequence of bases needed for DNA Polymerase to start working (complementary to first 20-30 bases of DNA)

2. Add Primers, Nucleotides, and DNA Polymerase

3. Heat DNA This separates 1 piece of DNA into 2 single strands

4. Let Cool As it cools, Primer joins to start of each single strand of DNA. Now DNA Polymerase can add bases New DNA Primer DNA Polymerase

Overview Original DNA Now have 2 pieces of DNA

5. Repeat Many Times

Link to Virtual PCR Lab

How to Sequence DNA

Add Single-Strand of DNA with an unknown sequence (order of nucleotides) Add nucleotides (A,G,C,T) Add a small amount of nucleotides that have chemical dyes attached (Each type of nucleotide has a different color).

Add DNA Polymerase. It will start adding bases using the unknown strand as a template. Every time a nucleotide with a dye is used the newly forming strand falls off the template strand. This means there will be many strands of varying length. Each of these pieces will have a different color dye. Place all of the pieces in DNA Gel-Electrophoresis. The pieces will separate based on length. Because the last nucleotide added to each length has a different color, we can tell the order of nucleotides.

Link to Sanger’s DNA Sequencing

Transgenics

Transgenics Taking the gene from 1 organism and putting into another organism

Recombinant DNA Foreign DNA DNA that has a piece of DNA from another organism Foreign DNA

Making Insulin

Diabetes A condition where a person can’t produce insulin

Making Insulin DNA using restriction enzyme 1. Cut insulin gene out of human DNA using restriction enzyme

2. Cut open the DNA of an E. Coli cell with SAME R. Enzyme

3. Insert Gene into Open Plasmid Insulin Gene

4. Use Ligase to “glue” gene in place 5. Incubate e-coli 4. Use Ligase to “glue” gene in place 5. Incubate e-coli. Every time they divide, they divide their DNA along with the human gene. Bacteria will produce insulin from the inserted gene.