Genetic Technology

How is DNA technology used? DNA Technology = creating DNA sequences in a lab to bring together genetic material from multiple sources, creating sequences that would not otherwise be found in biological organisms. How do you sequence DNA from organisms? How do you bring together genetic material from multiple sources?

DNA technology uses a process called gel electrophoresis Gel Electrophoresis = a method for separation and analysis of macromolecules (DNA, RNA and proteins) and their fragments, based on their size and charge.

Gel Electrophoresis produces a DNA fingerprint DNA Fingerprint = used in forensics; gives the DNA of an individual – Stained segments of DNA – Segments separated by size with Gel Electrophoresis

How to “read” a gel

What can reading gels be used to accomplish? 1.Identifying individuals 2.Cataloging endangered species Why could these be important to you? Why could these be important to science?

What are transgenic organisms and how do they benefit society? When genetic material from a different species is added, the resulting DNA is called recombinant DNA and the organism is called a transgenic organism. Transgenic organisms = an organism whose genetic material has been altered using genetic engineering techniques.

Transgenic Organisms Organisms with functional recombinant DNA are called Transgenic Organisms

Transgenic Organisms (AKA: Genetically Modified Organisms – GMOs) Examples: – bacteria – yeast – insects – plants – fish – Mammals GMOs are the source of genetically modified foods, and are also widely used in scientific research and to produce goods other than food.

Applications and Benefits of Transgenic Organisms… ApplicationsBenefits? Agriculture- Better tasting crops -Stay fresh longer -Resistant to disease Industrybacteria engineered to create chemicals -dye for denim jeans -Cheese -Laundry detergent -Paper products Pharmaceutical /Medicine -Human growth hormone for sick people - insulin for people with diabetes

How do you “produce” a transgenic organism?

What are the ethical issues surrounding the use of DNA technology? Cloning Genetically Modified Organisms (GMOs) Stem Cell Research Human Genome Project Gene therapy. (e.g. Severe Combined Immunodeficiency and Cystic Fibrosis)

Cloning Organism cloning (also called reproductive cloning) refers to the procedure of creating a new multicellular organism, genetically identical to another.

What could be some ethical issues surrounding cloning?

What could be some ethical issues surrounding Genetically Modified Organisms?

Human Genome Project Human Genome Project = international effort to completely map the human genome Finished in 2003

What could be some ethical issues surrounding Human Genome Project?

Gene Therapy Gene Therapy = Insertion of normal genes into human cells to correct genetic disorders

Gene Therapy is Used For Treating: Cystic Fibrosis – build-up of mucus in the lungs caused by a recessive genetic trait Severe Combined Immunodeficiency (AKA “bubble boy” disease) or SCID – SCID is the result of an immune system so highly compromised that it is considered almost absent. – SCID patients are usually affected by severe bacterial, viral, or fungal infections – Babies, if untreated, usually die within 1 year due to severe, recurrent infections How are individuals treated?

Treatment of SCIDS

SCIDS Treatments… In 2000, a gene therapy "success" resulted in SCID patients with a functional immune system. In 2007, four of the ten patients have developed leukemias. Work aimed at improving gene therapy is now focusing on modifying the viral vector to reduce the likelihood of oncogenesis No leukemia cases have yet been seen in trials of ADA-SCID, which does not involve the gamma c gene that may be oncogenic when expressed by a retrovirus. Trial treatments of SCID have been gene therapy's first success; since 1999, gene therapy has restored the immune systems of at least 17 children with two forms (ADA-SCID and X-SCID) of the disorder.

Treatment of Cystic Fibrosis

What could be some ethical issues surrounding gene therapy?

What is a stem cell? What do you know about the DNA in ALL the body cells in your body? It is the SAME!

What types of cells are in your body? What are the function of these cells? – Nerve – Muscle – Blood – Sperm – Xylem – Phloem

What are the function of these cells? Nerve Muscle Blood Sperm Xylem Phloem

How do these cells become different in structure and function?

What is a stem cell? Stem cells = unspecialized cells that continually reproduce themselves and have, under appropriate conditions, the ability to differentiate into one or more types of specialized cells. What does it mean to differentiate?

Stem Cell Research How do these cells that all have the same DNA end up looking so different? Differentiation = in multicellular organisms cells differ based on the expression of specific genes

Stem Cell Differentiation

Stem Cells

Quick Summary of Differentiation Nearly all the cells of a multicellular organism have exactly the same chromosomes and DNA Because all cells contain the same DNA, all cells initially have the potential to become any type of cell;

Quick Summary of Differentiation Only specific parts of the DNA are activated Different parts of the genetic instructions are used in different types of cells, influenced by the cell’s environment and past history The activated parts determine the function and specialized structure of the cell

Quick Summary of Differentiation once a cell differentiates, the process cannot be reversed Chemical signals may be released by one cell to influence the development and activity of another cell

Types of Stem Cells Embryonic stem cells = cells which have not differentiated into various cell types Adult stem cells = stem cells found in organisms (exaxmple: in bone marrow) BOTH types can differentiate into specialized cells!

How can you get Stem Cells? There are three accessible sources of autologous adult stem cells in humans: 1.Bone marrow which requires extraction by harvesting, that is, drilling into bone (typically the femur or iliac crest), 2.Adipose tissue (lipid/fat cells), which requires extraction by liposuction 3.Blood

Stem cells from bone marrow

What can they be used to do?

Your Task… 1.Define your topic! – What is it? – What does it cause/do/impact? 2.Use the internet to research ways in which these issues impact science and society. – List 3 ways it can be GOOD (pro’s) And WHY! For each… – List 3 ways it can be controversial (con’s) And WHY! For each… 3.Formulate an opinion – how do you (or your group) feel about this DNA technology?

Selective Breeding Selective Breeding = Selectively mating or crossing plants and animals with certain traits

Selective Breeding Pro’sCon’s Can select the best plant or animal -Time consuming (takes several generations) -Can lead to inbreeding

Selective Breeding Examples

Inbreeding Inbreeding = Mating between closely related individuals **Result  homozygous individuals; can bring out harmful recessive traits Breed = selected group of organisms bred for particular characteristics

Inbreeding

Different Breeds of Dogs

Test Cross Test Cross = cross of a individual of unknown genotype with an individual of known genotype JOB: look at the phenotype of the offspring  figure out the genotype of the parent

What does will the mystery parent’s genotype be?

Test Cross: example Brown dogs are dominant to white dog color. Brown : BB, Bb White: bb Mate a brown dog (unknown) with a recessive BB or Bb x bb b b B? Bb b b B? bb Bb bb Must be BB

Genetic Engineering Genetic Engineering = faster method of increasing the frequency of a desirable allele – Uses Recombinant DNA Technology Recombinant DNA = DNA that is made by connecting or recombining fragments of DNA from different sources

Recombinant DNA

Steps of Recombining DNA: 1.Remove/cut wanted DNA from organisms using a restriction enzyme

Steps of Recombining DNA: 2.Carry new DNA to cleaved site using a plasmid or vector

Recombining DNA – Plasmid = small ring of bacterial DNA; often used as a vector – Vector = biological or mechanical means of transferring DNA from one organism to another

Vector

Steps of Recombining DNA: 3.Insert/join DNA to new host

Recap: 1.Remove/cut wanted DNA from organisms using a restriction enzyme 2.Carry new DNA to cleaved site using a plasmid or vector 3.Insert/join DNA to new host

Vector

Transgenic Organisms

DNA Fingerprinting DNA Fingerprint = used in forensics; gives the DNA of an individual – Stained segments of DNA – Segments separated by size with Gel Electrophoresis