Presentation on theme: "Aim: How can we alter genetic make-up of organisms (should we) ? HW #12 Text read pages 327-329 Pg. 329 q. #2 and 4."— Presentation transcript:
Aim: How can we alter genetic make-up of organisms (should we) ? HW #12 Text read pages Pg. 329 q. #2 and 4
For thousands of years new varieties of cultivated plants and domestic animals have resulted from selective breeding for particular traits Brahman cattle: Good resistance to heat but poor beef English shorthorn cattle: Good beef but poor heat resistance. Santa Gertrudis cattle: Formed by crossing Brahman and English shorthorns; has good heat resistance and beef.
Lupins (Lupinus L.) are members of the legume family (subfamily Papilioniodeae) containing both herbaceous annual and shrubby perennial types with attractive long racemes of flowers
In recent years new varieties of farm plants and animals have been engineered by manipulating their genetic instructions to produce new characteristics 1994 The FDA approved the first genetically engineered food -- FlavrSavr tomatoes engineered for better flavor and shelf life.
Golden Rice - GMO created a rice cultivar that offers a metabolic precursor to vitamin A known as beta- carotene
Add traits Anti-freeze gene from fish
How do we add genes to another organism ? Recombinant Gene Technology involves changing the gene in an organism’s embryo (or seed in the case of plants) before it becomes a full grown organism
Bacteria has plasmids that are genetically changed Agrobacterium tumefaciens is a remarkable species of soil- dwelling bacteria that has the ability to infect plant cells with a piece of its DNA.
Aim: How do we change characteristics ? Making Human Insulin uses recombinant gene technology
Some recombinant DNA products being used in human therapy insulin for diabeticsinsulin factor VIII for males suffering from hemophilia Afactor VIII factor IX for hemophilia Bfactor IX human growth hormone (GH)human growth hormone erythropoietin (EPO) for treating anemiaerythropoietin three types of interferons, several interleukinsinterferonsinterleukins granulocyte-macrophage colony-stimulating factor (GM-CSF) for stimulating the bone marrow after a bone marrow transplantgranulocyte-macrophage colony-stimulating factor granulocyte colony-stimulating factor (G-CSF) for stimulating neutrophil production, e.g., after chemotherapy and for mobilizing hematopoietic stem cells from the bone marrow into the blood.granulocyte colony-stimulating factorneutrophil tissue plasminogen activator (TPA) for dissolving blood clotstissue plasminogen activator adenosine deaminase (ADA) for treating some forms of severe combined immunodeficiency (SCID)severe combined immunodeficiency angiostatin and endostatin for trials as anti-cancer drugsangiostatinendostatin parathyroid hormone leptin hepatitis B surface antigen (HBsAg) to vaccinate against the hepatitis B virushepatitis B surface antigenhepatitis B virus C1 inhibitor (C1INH) used to treat hereditary angioneurotic edema (HANE)C1 inhibitorhereditary angioneurotic edema
How was Recombinant DNA Technology used to develop Bt corn? Bt corn is a variant of maize, genetically altered to express the bacterial Bt toxin, which is poisonous to insect pests. In the case of corn, the pest is the European Corn Borer. maizegenetically alteredBtpoisonousinsect European Corn Borer
Bacillus thuringiensis (Bt) is a spore forming bacterium that produces crystals protein (cry proteins), which are toxic to many species of insects.
To transform a plant into a GMO plant, the gene that produces a genetic trait of interest is identified and separated from the rest of the genetic material from a donor organism. Most organisms have thousands of genes, a single gene represents only a tiny fraction of the total genetic makeup of an organism
Aim:How does gene therapy cure disease? Gene therapy is an experimental technique that uses genes to treat or prevent disease. In the future, this technique may allow doctors to treat a disorder by inserting a gene into a patient’s cells instead of using drugs or surgery. Researchers are testing several approaches to gene therapy, including: Replacing a mutated gene that causes disease with a healthy copy of the gene. Inactivating, or “knocking out,” a mutated gene that is functioning improperly. Introducing a new gene into the body to help fight a disease.
How is gene therapy carried out? The challenge of developing successful gene therapy for any specific condition is considerable. The condition in question must be well understood and the underlying faulty gene identified. (1) A working copy of the gene involved must be available, (2) The specific cells in the body requiring treatment must be identified and accessible and finally, (3) a means of efficiently delivering working copies of the gene to these cells must be available. Of all these challenges, the one that is most difficult is the problem of ‘gene delivery’ ie. how to get the new or replacement genes into the desired tissues.
Some of the ‘vectors’ for the role of delivering the working copy of the gene to the target cells include using: a) Harmless viruses One of the most promising methods currently being developed is the use of harmless viruses that can be used to carry genes into cells b) Stem cells Stem cells are immature cells that contain the genes that can differentiate or develop into cells with different functions.
Although gene therapy is a promising treatment option for a number of diseases (including inherited disorders, some types of cancer, and certain viral infections), the technique remains risky and is still under study to make sure that it will be safe and effective. Gene therapy is currently only being tested for the treatment of diseases that have no other cures.