Ch. 13.3: Genetically Engineered Organisms

Objectives:

1. Describe how biologists genetically modify plants and animals.

2. Explain a technique used to clone animals.

3. Summarize the GMO controversy

Vocabulary G.M.O. Transgenic

Selective Breeding: Old School Genetic Engineering indirect manipulation of DNA select parents with desirable traits create “better” individual oldest way to improve a species breed cats, dogs, horses, trees, mice

Selective Breeding: Methods1. Inbreeding

- to maintain traits in a population- mate parents with similar genomes- keeps desirable traits, but increases risks for undesirable mutations (illness/disease)

2. Outbreeding (Hybridization)- Crossing of distantly related organisms- offspring sterile but hardier (hybrid vigor)- ex. Mule, hybrid corn, ligers, etc.

Genetic Engineering

Direct manipulation of DNA- cutting and pasting of genes- design organisms or create transgenic organisms

Creates a transgenic organism- organism with foreign DNA or rDNA

Genetically Modified Organism = GMOAny organism that has acquired genes by artifical means.

Genetic Engineering: Basic Steps

1. Isolate desired DNA sequence Restriction enzymes cut and remove DNA sequences.

2. Attach desired DNA to a VECTORLigase binds DNA fr. different sources.

Vector = bacteria plasmid or virus that will carry recombinant DNA to host.

3. Cloning: Host organisms transcribes and translates desired DNA sequence. Makes MANY COPIES of enzyme or protein.

Creating Plant GMOs Applications

Insert genes for:

natural insecticides

Pesticides

Growing larger fruits/bigger flowers

Increase “nutrient” content.

Common in soybeans, rice, corn, wheat

Creating Animial GMOs

Applications

Bigger cattle, leaner meat

More milk production

Better wool production

Have animals produce human proteins to treat disorders.

Animal ClonesSteps

1. Remove nucleus fr. Egg.

2. Replace nucleus w/ nucleus (and chromosomes) fr. a somatic cell

3. Shock w/ electricity to stimulate cell division

4. Place embryo in surrogate female for gestation.

Sheep, cattle, dogs, cats, pigs, etc.

Problems: advanced aging and cancer in clones.

GMO Controversy

Pros: New genes can improve crops or animals.

Cons: Could GMOs be harmful to us?

New allergies? Cancer/illness?Not many studies. Not regulated.Economic concerns

Cloning & Stem Cell Controversy

Stem cells = undifferentiated cells that can turn into any type of cell (nervous, cardiac, skin, etc.)

Could be used to treat a host of illness/disease

Repair damaged spinal cord tissue

Replace damaged cardiac muscle

Sources: Embryos; Adult cells: bone marrow and cord blood (Embryos have the most promise/potential)

Therapeutic Cloning

Use embryonic stem cells to create specialized human cells.

Goal: Cure disease

Embryo does not develop into a human.

Allowed in U.S. (state by state) w/ restrictions

Reproductive Cloning

Create a human clone.

Strictly prohibited!