Genetic Engineering

What Do These Items Have In Common?

• DNA (deoxyribonucleic acid) is the genetic code responsible for giving organisms certain phenotypes. – By changing the DNA,

we can change the organism!

DNA

What is Genetic Engineering?

• A deliberate, controlled manipulation of genes in an organism with the intent of making that organism better in some way.

• The use of various experimental techniques to produce: – novel combinations of genes– molecules of DNA containing new genes

Time to eat your VITAMIN corn!

• SELECTIVE BREEDING– Allowing only those organisms with desired characteristics to

produce the next generation

What types of organisms have been selectively bred by humans?– horses– dogs– cats– farm animals– most crop plants

Genetic Engineering by Combining Genes

Animal Breeding

Genetic Engineering Continued:

• Using genetic engineering, you can cross traits that belong in different species.

– First, get a sample of the gene you wish to transfer from one organism to another

– Use enzymes to cut certain DNA sequences that code for the desired characteristic.

• Restriction Enzyme

How Restriction Enzymes Work

Restriction Enzymes make the

“cut” after a certain code.

Like: Cut after TTAA sequence

Continued…

• Insert the code into tiny circles of bacterial DNA called plasmids

• Allow plasmids carrying the gene to infect a culture of bacterial cells

• Grow each of these cells as a pure cell culture

• Through a screening process, select an adequate gene that will stick to others via A,T,C,G

Continued…

• Take selected object you want modified, open pores of the cell membrane, and insert gene into cell.

• By various methods (like particle guns) selected genes will combine with the natural DNA, therefore altering the original sequence. This phase of genetic engineering varies depending on the organism.

Gene Encoded on Plasmid

Genetically Engineering Causes Genetic

Modification• By using this process, humans can “genetically modify” several

organisms. – Foods– Animals– Bacteria

• Genetically modified (GM) foods are foodstuffs produced from genetically modified organisms (GMO) that have had their genome altered through genetic engineering. GM Foods have been available since the 1990s

• Most common examples of GM foods:– Soybean– Corn– Canola– Wheat– Tomatoes

But WHY Do This?

• As stated before, the overall goal is to create a product better than the original. We look at agriculture as our main example

In The Past• Early forms of genetic modification were

done by hand

• The earliest Farmers altered the genetic makeup of corn

• Corn's ancestor, a grass called teosinte, had small ears with sparse kernels

• As humans selected teosinte ears bearing the most plump kernels, they gradually edged evolution towards forming a new species, corn

• The jackets formed by the leaves covering an ear of corn (husks) are so tight that the plant cannot naturally release its seed. This would not benefit a plant in the wild

Today’s Use

• pest resistance

• herbicide tolerance

• disease resistance

• cold tolerance

• nutritional abundance

• pharmaceutical additions

• shelf life

By altering the original DNA of the plants, we can create new plants with several advantages. (Can you guess what these are?)

Negative Effects

• Environmental activists, religious organizations, public interest groups, profession associations, and other science and government officials have raised concerns about GM foods and its potential hazards.

Potential Problems with GM foods include:

- Allergens- Gene transfer to non-target species- Reduced effectiveness of pesticides- Unintended harm to other organisms

Should We Continue?

• 75% of all crops grown in the U.S. contain some type of GM gene at varying degrees

• These enhanced plants are not only good for the American wallet, but they can help other third world countries in fighting starvation

• Do you agree with the use of GM foods?

Genetic Modification on Animals

• The latest trend in genetic engineering is now experimentation on animals

Pharming

• Genetic modification on farm animals has potential to lower prices and enhance enrichment, however, the ethics behind this are very strong, so research is kept at bay.

• Two common types of pharming include injecting cows with hormones so that the milk they produce will have proteins of potential medical benefit as well as pharmaceutical products

Question: Does cow milk contain Vitamin D?

Answer: NO! The hormone is injected after pumping, Adding Vitamin D to milk is like adding Iodine to salt….GM eliminates a step in the food processing process.

Pharming• A recent genetic modification concerns breeding

featherless chickens. Because there are more chickens than people in the world, plucking is very time consuming and costly.

Genetic Modification of Bacteria

• Scientists can modify the gene code of bacteria. – Bacteria can now produce insulin or other

hormones people need.