Section 4-5Section 4-5What is the future of evolution?What is the future of evolution?

Genetic EngineeringGenetic Engineering

Artificial Selection and Genetic Artificial Selection and Genetic EngineeringEngineering

• Artificial Selection: Artificial Selection: to change (selectively to change (selectively manipulate) the genetic characteristics of manipulate) the genetic characteristics of populations of a species.populations of a species.

• Artificial selection has led to food crops with Artificial selection has led to food crops with higher yields, cows that produce more milk, higher yields, cows that produce more milk, variation in pets and livestock.variation in pets and livestock.– Ex: corn, most “breeds” of dog and catEx: corn, most “breeds” of dog and cat

Bullmastiff: Bullmastiff: bulldog bulldog and english mastiffand english mastiff

RagdollRagdoll: persian & : persian & himalayanhimalayan

Genetic EngineeringGenetic Engineering

• Gene splicing: Gene splicing: isolating, modifying, multiplying, isolating, modifying, multiplying, and recombining genes from different organisms.and recombining genes from different organisms.

• Why is it useful?Why is it useful?• This allows scientists to place desired genetic traits This allows scientists to place desired genetic traits

into species of plants and animals that would never into species of plants and animals that would never interbreed in nature.interbreed in nature.

Images borrowed from “Worth1000” website

THESE ARE NOT THESE ARE NOT ACTUAL ANIMALS!ACTUAL ANIMALS!

Fig. 4-11, p. 75

Phase 1Make Modified Gene

Identify and extractgene with desired trait

Identify and removeportion of DNAwith desired trait

Remove plasmidfrom DNA of E. coli

Insert extracted DNA(step 2) into plasmid(step3)

Insert modifiedplasmid into E. coli

Grow in tissueculture to

make copies

Cell

plasmid

E. coli

DNA

Geneticallymodifiedplasmid

Extract plasmid

Genetic Engineering:PHASE 1

Gene of interest

Extract DNA

Fig. 4-11, p. 75

Phase 2Make Transgenic Cell

Transfer plasmid copies to a carrier agrobacterium Agrobacterium inserts foreign

DNA into plant cell to yield transgenic cell

Transfer plasmidto surfacemicroscopic metalparticle

Use gene gunto inject DNAinto plant cell

A. tumefaciens(agrobacterium) Host DNA

Foreign DNA

Genetic Engineering:PHASE 2

E. coli

Nucleus

Fig. 4-11, p. 75

Phase 3Grow Genetically Engineered Plant

Transgenic cellfrom Phase 2

Cell division oftransgenic cells

Culture cellsto form plantlets

Transgenic plantswith new traits

Transfer to soil

Genetic Engineering: PHASE 3

GMO’SGMO’S

• Genetically modified organisms aka transgenic Genetically modified organisms aka transgenic organisms: products of gene splicing.organisms: products of gene splicing.

• Gene splicing takes about ½ the time of conventional Gene splicing takes about ½ the time of conventional crossbreeding to develop a new crop or animal and costs crossbreeding to develop a new crop or animal and costs significantly less.significantly less.

• Products: crops, animals, drugs, pest-resistant plants, useful Products: crops, animals, drugs, pest-resistant plants, useful bacteriabacteria

• Question: Does anyone use or know someone who uses Question: Does anyone use or know someone who uses insulin?insulin?

• Question: Do you eat low cholesterol eggs?Question: Do you eat low cholesterol eggs?• Question: Did you know some fruits and veggies can be Question: Did you know some fruits and veggies can be

modified to carry vaccines? Benefits???modified to carry vaccines? Benefits???

GMO’SGMO’S

• Biopharming: plants and animals used to Biopharming: plants and animals used to produce pharmaceutical proteins and chemicals.produce pharmaceutical proteins and chemicals.

• As of 2002 plants have been engineered to produce a As of 2002 plants have been engineered to produce a contraceptive, potent growth hormones, a blood clotter, contraceptive, potent growth hormones, a blood clotter, blood thinners, industrial enzymes and vaccines. Corn is by blood thinners, industrial enzymes and vaccines. Corn is by far the most popular biopharm plant, followed by soybeans, far the most popular biopharm plant, followed by soybeans, tobacco and rice. Some 400 biopharm products are tobacco and rice. Some 400 biopharm products are reportedly in the pipeline, and over 300 open-air field trials reportedly in the pipeline, and over 300 open-air field trials have already been conducted in unidentified locations have already been conducted in unidentified locations across the United States.(1)across the United States.(1)

1 USDA Field Trial website. The Information Systems for Biotechnology website is run for the USDA by Virginia Tech University. See http://www.nbiap.vt.edu/cfdocs/fieldtests1.cfm.

CloneClone

• Genetically identical version of an individual Genetically identical version of an individual in a populationin a population

Recombinant DNA Technology or DNA Cloning

• the transfer of a DNA fragment of interest from one organism to a self-replicating genetic element such as a bacterial plasmid.

Reproductive Cloning

• Reproductive cloning is a technology used to generate an animal that has the same nuclear DNA as another currently or previously existing animal. Dolly was created by reproductive cloning technology. In a process called "somatic cell nuclear transfer" (SCNT), scientists transfer genetic material from the nucleus of a donor adult cell to an egg whose nucleus, and thus its genetic material, has been removed. The reconstructed egg containing the DNA from a donor cell must be treated with chemicals or electric current in order to stimulate cell division.

Therapeutic Cloning

• Therapeutic cloning, also called "embryo cloning," is the production of human embryos for use in research. The goal of this process is not to create cloned human beings, but rather to harvest stem cells that can be used to study human development and to treat disease.