Unit 9 Seminar: GENETIC ENGINEERING AND TRANSGENIC ORGANISMS Evelyn I. Milian Instructor 2011 SC235 – General Biology I: Human Perspectives

Unit 9 Seminar:GENETIC ENGINEERING AND TRANSGENIC ORGANISMS

Evelyn I. MilianInstructor

2011

SC235 – General Biology I: Human Perspectives

SC235-General Biology I - Unit 9 Seminar – Genetic Engineering and Transgenic Organisms

TRANSGENIC ORGANISMS – FIELD TRIP!!!

Recombinant DNA Technology / Genetics / Biology: http://www.youtube.com/watch?v=TpmNfv1jKuA

Genetically Modified Organisms (GMOs): Transgenic Crops and Recombinant DNA Technology: http://www.nature.com/scitable/topicpage/genetically-modified-organisms-gmos-transgenic-crops-and-732

Transgenic Animals: Their Benefits to Human Welfare: http://www.actionbioscience.org/biotech/margawati.html

GM Organisms: http://www.newscientist.com/topic/gm-food

Regulation of Genetically Engineered Animals: http://www.fda.gov/ForConsumers/ConsumerUpdates/ucm048106.htm

Cloning: http://www.genome.gov/25020028

Creating a Cloned Sheep Named Dolly: http://science-education.nih.gov/home2.nsf/Educational+ResourcesTopicsGenetics/BC5086E34E4DBA0085256CCD006F01CB

2011 Evelyn I. Milian - Instructor 2


Introduction: Biotechnology

Biotechnology is the manipulation of organisms, cells or their components to make a specific useful product.

Some traditional applications of biotechnology are thousands of years old. The history of biotechnology includes such early practices as: Selective breeding of farm animals & plants for many years. Using microorganisms to make wine, cheese and other food

products. Over 10,000 years ago, ancient civilizations in Egypt and the Near East produced beer and wine, unaware that these alcoholic beverages are naturally fermented by yeast (a fungus).

Other modern applications include: Production of antibiotics, enzymes and other biological

molecules, foods, vaccines, vitamins.



Genetic Engineering, A Modern Form of Biotechnology

Genetic engineering is the manipulation of genes to alter the characteristics of an organism or a cell in a desired way.

Since 1970s, DNA technology (methods of working with and manipulating DNA, the genetic material of cells) allows the production of recombinant DNA molecules when segments of DNA from two different sources—often different species—are combined in vitro (in the lab).

Major goals of genetic engineering include:

1. Learning more about cellular processes, including inheritance and gene expression.

2. Medical research to understand and treat diseases, particularly genetic disorders.

3. Generating economic and social benefits in agriculture, efficient production of valuable biological molecules, criminal investigation, and other areas.



GENETIC ENGINEERING TERMINOLOGYCloning Production of identical copies of genes, cells, or

organisms. The copied material, which has the same genetic makeup as the original, is referred to as a clone.

Gene cloning Production of many identical copies of a gene.Gene cloning is useful for two basic purposes:

to make copies of a particular gene and to produce a protein product.

Therapeutic cloning A procedure in which damaged tissues or organs are repaired or replaced with genetically identical cells that originate from undifferentiated stem cells.

Organismal or reproductive cloning

Production of organisms with the same genes; the process of engineering a new individual entirely from the genetic material in a cell from another individual.

Genetically modified organism (GMO), or genetically engineered organism (GEO)

An organism whose genetic material has been altered using genetic engineering techniques. A transgenic organism carries genes (DNA) of another organism or species in its cells.







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Biotechnology Applications:DNA Cloning Using a Bacterium

Cloning a Human Gene: Human DNA and plasmid DNA

are cleaved by a specific type of restriction enzyme. For example, human DNA containing the insulin gene is spliced into a plasmid by the enzyme DNA ligase. Gene cloning is achieved after a bacterium takes up the plasmid. If the gene functions normally as expected, the product (e.g., insulin) may also be retrieved.

* Remember: cloning is the production of genetically identical copies of DNA, cells, or organisms through some nonsexual means.

Evelyn I. Milian - Instructor


Applications of Genetic Engineering in Agriculture:Genetically Modified Crops



Genetic Engineering in Agriculture: Transgenic Plants


The Bt gene was added to NewLeaf potatoes (middle row) using the bacterium Agrobacterium tumefaciens as a vector. These potatoes resist attack by Colorado potato beetles and consequently are much healthier than nontransgenic plants (right and left rows).

DNA technology also has the potential to develop crops that are more nutritious. For example, in the 1990s geneticists engineered rice to produce high quantities of B-carotene, which the human body uses to make vitamin A, important for vision.


Applications of Genetic Engineering:Currently Used Products Produced by Recombinant DNA Methods




DNA Technology Applications:Transgenic Mammals

a. A genetically engineered egg develops in a host goat to create a transgenic goat that produces a biotechnology product, such as human growth hormone, in its milk.

b. Nuclei from the transgenic goat are transferred into donor eggs, which develop into cloned transgenic goats.


Genetically Modified Animals (Transgenic Animals)


Certain transgenic animals produce foreign proteins of therapeutic or commercial importance that are secreted into milk. Producing livestock, such as pigs, sheep, cows, and goats, that secrete foreign proteins in their milk is known informally as “pharming”, a combination of “pharmaceuticals” and “farming”.


Genetically Modified Animals (Transgenic Animals)


Figure 15-15. A transgenic mouse. The mouse on the right is normal, whereas the mouse on the left is a transgenic animal that expresses rat growth hormone.

Figure 15-16. Transgenic “pharm” cows. These cows contain a human gene that codes for lactoferrin, a protein found in human mothers milk and in secretions such as tears, saliva, bile, and pancreatic fluids. Lactoferrin helps in defense against disease-causing microorganisms.


DNA Technology: Reproductive Cloning in Mammals

In 1997, Scottish researchers announced to the world the birth of Dolly (born in 1996) a lamb cloned from an adult sheep by nuclear transplantation from a differentiated cell (a mature cell).

Nuclear transplantation is the removal of the nucleus of an unfertilized or fertilized egg and replacing it with the nucleus of a differentiated egg.

Dolly died in 2003, at age 6, from lung disease.

Dolly’s premature death, as well as her arthritic condition, led to speculation that her cells were in some way not quite as healthy as those of a normal sheep, possibly reflecting incomplete reprogramming of the original transplanted nucleus.

Since 1997, researchers have cloned numerous other mammals, including mice, cats, cows, horses, mules, pigs, and dogs.



Reproductive Cloning of Mammals

This method is used to produce cloned animals whose nuclear genes are identical to those of the animal supplying the nucleus.

Shown here is the procedure used to produce Dolly, the first reported case of a mammal cloned using the nucleus of a differentiated cell (in 1996).

The genetic makeup of the cloned animal is identical to that of the animal supplying the nucleus but differs from that of the egg donor and surrogate mother. (The latter two are “Scottish blackface”: sheep, with dark faces.)

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Reproductive Cloning of Mammals




If I were you, I would avoid transgenic mice.

CC, the first cloned cat (right) and her single parent (left). Rainbow (left) donated the nucleus in a cloning procedure that resulted in CC.

However, the two cats are not identical. Rainbow is a classic calico cat with

orange patches on her fur and has a “reserved personality”, while CC has a

gray and white coat and is more playful.


Genetic Engineering Applications:Human Gene Therapy

Gene therapy is the insertion of genetic material into human cells for the treatment of a disorder.

Gene therapy has been used to cure inborn errors of metabolism as well as to treat more generalized disorders such as cardiovascular disease and cancer.

192011 Evelyn I. Milian - Instructor



In “ex-vivo gene therapy” a normal gene is inserted into cells that have been removed and then returned to the body. In “in vivo gene therapy”

the gene is delivered directly into the body.


Stem Cells forTherapeutic Cloning

Stem cells, which can be isolated from early embryos or adult tissues and grown in culture, are relatively unspecialized cells that can reproduce indefinitely and under appropriate conditions, differentiate into specialized cells of one or more types.

Embryonic stem cells are easier to grow than adult stem cells and can in theory give rise to all types of cells in an organism. The range of cell types that can arise from adult stem cells is not yet fully understood.

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What Are the Major Ethical and Safety Issues Surrounding Modern Biotechnology and Genetic Engineering (Including Cloning)?

Modern biotechnology offers the promise—some would say the threat—of greatly changing our lives and the lives of many other organisms on Earth. As the movie Spiderman noted, “With great power comes great responsibility.” Is humanity capable of handling the responsibility of genetic engineering?

Enormous controversy swirls around many applications of biotechnology. Two such controversies are:

The use of genetically modified organisms (animals and plants) in agriculture.

Prospects for genetically modifying human beings.



Should Genetically Modified OrganismsBe Permitted in Agriculture?

The aim of agricultural biotechnology and genetic engineering is to modify the genetic makeup of living organisms (animals and plants) to make them more useful, for example:

Creating disease-resistant and herbicide-resistant crops

Creating drought or temperature-resistant crops

Providing health benefits such as increasing the nutritional content of foods

Reducing the use of fertilizers

Increasing the food supply (potential to decrease world hunger)

Increasing shelf-life of food products


Should Genetically Modified OrganismsBe Permitted in Agriculture?

The use of genetically modified organisms (GMOs) in agriculture is controversial for two main reasons: food safety and environmental protection. In general, GMOs contain proteins that are harmless to mammals, are

readily digested, or already found in other foods.

The transfer of potentially allergenic proteins to normally nonallergenic foods can be avoided by thorough testing.

If they escape, highly mobile transgenic animals might displace their wild relatives. Fortunately, most domesticated animals, such as cattle or sheep, are not highly mobile.

Scientists have stringent guidelines and regulations for using genetic engineering. So far, no evidence suggests that researchers have accidentally cloned hazardous genes or have released dangerous organisms into the environment. However, malicious intentional manipulations of dangerous genes remain a concern.




Should a Human Genome Be Changedby Genetic Engineering?

Genetically selecting or modifying human embryos is highly controversial.

Should parents use information obtained through biotechnology as a basis for therapeutic abortion or to prepare to take care for a child with a genetic disease?

Should people be allowed to select the genomes of their offspring, or, even more controversially, should they be allowed to change the genomes?

As technologies improve, society may be faced with decisions about the extent to which parents should be allowed to correct or enhance the genomes of their children.



Case Study: Should a Human Genome Be Changed by Biotechnology?

Several years ago, a girl in Colorado was born with Franconi anemia, a genetic disorder that causes not only anemia but also skeletal abnormalities, such as missing thumbs. It is fatal without a bone marrow transplant. Her parents wanted another child—a very special child, without Franconi anemia, who could serve as a donor for their daughter. They went to Yury Verlinsky of the Reproductive Genetics Institute for help. Verlinsky used the parents’ sperm and eggs to create dozens of embryos in culture. The embryos were then tested for the genetic defect and for tissue compatibility with the couple’s daughter. Verlinsky chose an embryo with the desired genotype and implanted it into the mother’s uterus. Nine months later, a son was born. Blood from his umbilical cord provided cells to transplant into his sister’s bone marrow. Today, both children are healthy. Was this an appropriate use of genetic screening? Should dozens of embryos be created, knowing that the vast majority will be discarded? Is this ethical if it is the only way to save the life of another child? Assuming that it’s possible someday, would this be an ethical method of selecting embryos that would grow up to be bigger or stronger football players?

Source: Audesirk, Teresa; Audesirk, Gerald & Byers, Bruce E. (2005). Biology: Life on Earth. Seventh Edition. Pearson Education, Inc.-Prentice Hall. NJ, USA.


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Human cloning technology might allow permanent correction of

genetic defects.

In this process, human embryos are derived from eggs fertilized in culture dishes using sperm and eggs from a man and a woman, one or both of whom have a genetic disorder. When an embryo containing a defective gene grows into a small cluster of cells, a single cell would be removed from the embryo and the defective gene is replaced using an appropriate vector. The repaired nucleus could then be implanted into another egg (taken from the same woman) whose nucleus had been removed. The repaired egg cell would then be implanted in the woman’s uterus for normal development.

Evelyn I. Milian - Instructor


Should a Human Genome Be Changed by Genetic Engineering?

Modifying the human genome has profound ethical implications even beyond the unexpected risks.

To many of us, human gene therapy to correct genetic disorders seems like a socially acceptable goal.

However, is it acceptable to change some genes of a normal human in order to alter or enhance traits? Engineering tall or blue-eyed or fair-skinned children? Engineering “superhumans” with amazing strength or intelligence? Recent surveys:

More than 40% interviewed individuals in U.S. said it would be fine to use gene therapy to make smarter and better looking babies.

British parents interviewed: 18% would use genetic enhancement to prevent their children from being aggressive; 10% were willing to use it to keep them from growing up to be homosexual.



Questions???

Unit 9 Final Project:Formatted according to APA style.Basic presentation and contents: Title page,

introduction, discussion (body), conclusion, page of references (more than one reference, all references discussed and properly cited in your work).

Answer all questions in assignment.Must be a minimum of 1,500 words.

Contact me if you have questions: [email protected] Best wishes to all! Stay in touch!



References

Audesirk, Teresa; Audesirk, Gerald & Byers, Bruce E. (2005). Biology: Life on Earth. Seventh Edition. Pearson Education, Inc.-Prentice Hall. NJ, USA.

Campbell, Neil A.; Reece, Jane B., et al. (2008). Biology. Eighth Edition. Pearson Education, Inc.-Pearson Benjamin Cummings. CA, USA.

Enger, Eldon D.; Ross, Frederick C.; Bailey, David B. (2007). Concepts in Biology. Twelfth Edition. The McGraw-Hill Companies, Inc. NY, USA.

Ireland, K.A. (2011). Visualizing Human Biology. Second Edition. John Wiley & Sons, Inc. NJ, USA.

Mader, Sylvia S. (2010). Biology. Tenth Edition. The McGraw-Hill Companies, Inc. NY, USA.

Solomon, Eldra; Berg, Linda; Martin, Diana W. (2008). Biology. Eighth Edition. Cengage Learning. OH, USA.

Starr, Cecie. (2008). Biology: Concepts and Applications Volume I. Thompson Brooks/Cole. OH, USA.

Trefil, James & Hazen, Robert M. (2011). The Sciences An Integrated Approach. Sixth Edition. John Wiley & Sons, Inc. NJ, USA.

2011 30Evelyn I. Milian - Instructor

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Unit 9 Seminar: GENETIC ENGINEERING AND TRANSGENIC ORGANISMS Evelyn I. Milian Instructor 2011 SC235 – General Biology I: Human Perspectives