DNA Technology Terminology USES of DNA technology DNA

DNA Technology • Terminology • USES of DNA technology • DNA fingerprinting • protein production • gene therapy • GMO - Genetically Modified Organisms • cloning • Stem Cells • Genetic Counseling

Nucleic Acids: DNA & RNA - review • DNA • deoxyribonucleic acid • w/in DNA • genes: specific locations in DNA that codes for proteins or traits • program the production of proteins • determines traits for organisms • RNA • helps in translating code

fig 3. 6 b DNA & RNA - monomers: nucleotides • sugar • DNA - deoxyribose • RNA - ribose • phosphate group • nitrogenous bases • DNA - • adenine (A); thymine (T); cytosine (C); and guanine (G) • RNA - • same, except uracil (U) instead of thymine

Closer Look at DNA molecule - string of nucleotides: • backbone of sugar & phosphate • deoxyribose • four bases • A, T, G, C • double helix • twisted double stranded molecule

Base Pairing: • AT/GC rule – A with T – G with C • 2 DNA strands are complementary fig 11. 11

• DNA gene sequence • m. RNA & t. RNA work together to determine • 3 -base codons code for specific amino acids • sequence of amino acids determine specific proteins

How does proteins affect observable traits of organisms? Example: eye color in fruit flies • normal gene codes for red eyes • Mutations code for brown or white

DNA Technology - Terminology: Restriction Enzyme • cut DNA in specific spots depending on the code in the enzyme Bacterial Vectors • Bacteria used to carry pieces of genetic information from other organisms • plasmids – ring shaped DNA • Recombinant DNA • Bacterial plasmid and inserted gene

Restriction Enzymes: • cut DNA • enzymes • cut at specific base sequence

Forming Recombinant DNA using Restriction Enzymes: • cut DNA at specific sequences creating fragments • addition of DNA from other source • new DNA fragment created • joined by ligase

Making “customized” bacteria

Uses of DNA technology: (1) DNA fingerprinting • Extract a sample of DNA • break cell & nuclear membranes • cut DNA with restriction enzymes • separate DNA fragments using electrophoresis • Make DNA visible by staining and attaching to radioactive markers fig 11. 2

Gel Electrophoresis: • DNA is a negatively charged molecule • placing it on a special liquid gel and running current through the gel will cause DNA to move from negative pole to positive pole • the large fragments move the least • Smaller fragments move the farthest fig 11. 2

Reading the gels: fig 11. 5

Uses of DNA technology: (2) Protein production • use of microbes & cultured cells • produce • bacterial clones grown • protein fig 11. 12

Uses of DNA technology: (3) Gene Therapy • patient has defective gene • • • virus • inserts • bone marrow stem cells have potential to develop into different blood / immune cells fig 11. 19

Uses of DNA technology: (4) Genetically Modified Organisms • • “increase” • bt. Corn (resistant to corn borer) • golden rice (increase of Vitamin A production)

Uses of DNA technology: (4) Cloning • clone: genetic replica • reproductive cloning • • therapeutic cloning • • • fig 11. 17

Stem Cell categories • Totipotent – – • Pluripotent –Embryonic Stem cells (ES cells) –Embryonic Germ cells (EG cells) – – a single cell – source: – ES: – EG:

Stem Cell categories • Multipotent –can differentiate –Hematopoietic stem cells (HScs) – umbilical cord blood – bone marrow • Unipotent – –

Genetic Counseling: • Genes for particular disorders are known • • • may be markers than can be tested for • determine probability of • Huntington’s Disease • • Breast Cancer •

Genetic Testing // IVF Genetic Screening • pedigree analysis or direct genetic testing available for Cystic Fibrosis • parents with a family history of Cystic Fibrosis can screen embryos for the disorder PRIOR to in vitro fertilization • • fertilization occurs • single cell removed • embryos • first child as the result of this screening born in 1990