MODERN GENETIC APPLICATIONS Gel Electrophoresis Cloning Genetic Engineering

MODERN GENETIC APPLICATIONS • • • Gel Electrophoresis Cloning Genetic Engineering Selective Breeding/Artificial Selection Bioethics

Gel Electrophoresis • the separation of DNA, RNA, & protein via an electric charge • usually performed forensic purposes/solving crimes • Also used for paternity tests, and to see which 2 species are most closely related, etc.

How Does It Work? • “Gel” refers to the material used to separate the molecules (usually agar) • “Electrophoresis” refers to the electrical current used to move the molecules (DNA segments/DNA fragments) through the gel • Restriction enzymes cut the DNA between specific bases into fragments • Smaller fragments move farther away from the wells than larger fragments of DNA

GOAL of Gel Electrophoresis • To find the matching banding pattern of DNA • Compare the samples of DNA from the “suspects” to the sample found at the crime scene • Compare the unknown samples of DNA to the known DNA and see which ones have either identical banding patterns or that have the MOST BANDS of DNA in common!!!

Genetic Engineering

Genetic Engineering Vocabulary • Plasmids – molecules of DNA that are found in bacteria separate from the bacterial chromosome • Restriction enzymes – special enzymes that cut DNA at specific places, producing fragments • E. coli – a common bacteria that lives in the human intestine; a favorite organism used in Genetic Engineering, as cultures are easy & inexpensive to grow • Recombinant DNA – DNA that is created artificially that contains both the original and new inserted segment of DNA

What is Genetic Engineering? • It is the process used to isolate a gene from the DNA of one organism and transfer the gene into the DNA of another organism • Four steps are involved…

4 Steps to Genetic Engineering: 1. 2. 3. 4. Cleaving DNA Producing recombinant DNA Cloning cells Screening cells

1. Cleaving DNA • The DNA that contains the gene you want to isolate is cut into fragments using special enzymes called restriction enzymes that cleave (cut/separate) the sequences of nucleotides (DNA)

2. Producing Recombinant DNA • The cleaved (cut or new DNA fragment) is put into the DNA of a virus or plasmid (host cell) • The plasmid is then able to replicate (make copies of itself) with the new DNA in it • This produces Recombinant DNA = DNA made out of combining the DNA of 2 organisms

3. Cloning Cells • These cells with recombinant DNA in them are isolated and reproduce (via mitosis) • Growing a large # of genetically identical cells from a single cell is called cloning • Cloned cells are exactly the SAME genetically as the parent cell (mitosis)

4. Screening Cells • Bacterial cells that have received the particular gene of interest are identified and isolated

How human insulin is produced via Genetic Engineering

• Using procedures like this, many human genes have been cloned in E. coli or in yeast • This has made it possible — for the first time — to produce unlimited amounts of human proteins in vitro (in a test tube/petri dish) • Cultured cells (E. coli, yeast, some mammalian cells) transformed with a human gene are being used to manufacture more than 100 products for human therapy.

Some examples are: • insulin for diabetics • Factor VIII for those suffering from hemophilia • Human Growth Hormone (HGH) • Erythropoietin (EPO) for treating anemia • several types of Interferons (a chemical to help block viruses) • (GM-CSF) for stimulating the bone marrow after a bone marrow transplant • TPA for dissolving blood clots • Parathyroid hormone • Hepatitis B surface antigen (HBs. Ag) to vaccinate against the Hepatitis B virus

CLONING • The process of making an exact replica of an organism • Occurs naturally through asexual reproduction • The offspring produced is genetically IDENTICAL to the parent

Why haven’t we cloned a human yet?

Artificial Selection/Selective Breeding • A practice that has been used for thousands of years • Individual organisms are handpicked to breed with one another • This allows people to select the desired traits they’d like to appear in the offspring • Ex. Big juicy fruit • Lap dogs, guard dogs, hunting dogs • Race horses • NOTE: This is an unnatural way to speed up evolution vs. natural selection

Artificial Selection/Selective Breeding • Ex. DOGGIES!!! (all of the different dog breeds) – Labrador retriever – Standard Poodle – Labradoodle – The traits/qualities we like were selected for…

Other examples of Artificial Selection/Selective Breeding Select for the desired traits… • Race Horses – Breed the fastest horses with the strongest ones Strawberries – cross-pollinate the BIGGEST, SWEETEST, JUICIEST and REDDEST ones

Cross-pollinate the biggest pumpkins with the biggest pumpkins… = A HUGE PUMPKIN!!!

Genetic Engineering in Agriculture UNNATURAL!!! EXAMPLES… • Seedless grapes, watermelon, clementines, etc. • Seeds with fertilizers or pesticides in them • Drought-resistant seeds for crops Why do this? • Easier to eat • More nutritious • Tougher skin (tomatos, grapes) • Farmers don’t have to spray additional chemicals on crops • Crops can now grow in dry areas

Bioethics Questions… • Are we “messing with Nature? ” • Is this NATURAL? • What are the effects on the ecosystems/Earth of planting genetically engineered crops? • Are these plants healthy for us to eat? • Do we have all of the ANSWERS?

Seedless Watermelon Regular (Seeded) Watermelon

GENETIC Engineering's FUTURE… The impossible – OR could this be POSSIBLE?

Dolly, the cloned sheep

QUESTIONS/CONCERNS… • Is it Ethical? • Is it Moral? • Is it Justified? • Science vs. Nature

Types of Genetic Engineering 1. Somatic (Body Cells) • involves adding genes to cells other than egg or sperm cells. • Non-inheritable; if a person had a disease caused by a defective gene, a healthy gene could be added to the affected cells to treat the disorder. • non-inheritable, i. e. the new gene would not be passed to the recipient’s offspring.

2. Germline • involves changing genes in eggs, sperm, or very early embryos. • Inheritable; meaning that the modified genes would appear not only in any children that resulted from the procedure, but in all succeeding generations. • controversial due to the ability to change the very underlying nature of humanity in fundamental ways according simply to personal values of the individuals undergoing or performing the change on their children.