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

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 fig 3.6b

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 mRNA & tRNA 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

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 DNA Technology - Terminology:

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

(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 Uses of DNA technology: fig 11.2

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 Gel Electrophoresis: fig 11.2

Reading the gels: fig 11.5

(2) Protein production Uses of DNA technology: use of microbes & cultured cells open plasmid and insert human gene (use restriction enzymes) transfer back into bacteria bacterial clones grown protein can then be harvested fig 11.12

(3) Gene Therapy Uses of DNA technology: infant has defective gene which causes cells to not function normally insert normal gene for the child’s defective gene into a virus use the virus to insert the normal gene into defective stem cell grow the genetically altered stem cells and then insert them back into the infant fig bone marrow stem cells have potential to develop into different blood / immune cells

(4) Genetically Modified Organisms Uses of DNA technology: use recombinant DNA to produce organisms with new traits examples btCorn (resistant to corn borer) golden rice (increase of Vitamin A production)

(4) Cloning Uses of DNA technology: clone: genetic replica reproductive cloning transfer of a nucleus from a donor adult cell (somatic cell) to an egg which has no nucleus therapeutic cloning cells that are created through cloning are permitted to divide repeatedly to form a blastocyst. extract stem cells from the blastocyst use those cells to grow tissue that are a perfect genetic match for the patient. fig 11.17

Stem Cell categories Totipotent – ability of a single cell to divide and produce all the differentiated cells in an organism – including extraembryonic tissues (placenta) Pluripotent potential to differentiate into any of the three germ layers: endoderm, mesoderm, or ectodermdifferentiategerm layers Embryonic Stem cells (ES cells) –derived from embryos that develop from eggs that have been fertilized in vitro –Embryonic Germ cells (EG cells) –precursors of the gametes.gametes

Multipotent –can give rise to several other cell types, but those types are limited in number. Unipotent – capacity to develop/differentiate into only one type of tissue/cell type Stem Cell categories

Genetic Counseling: Genes for particular disorders are known may be markers that can be tested for determine probability of offspring contracting the disease Huntington’s Disease 4 million bases on the fourth chromosome Breast Cancer located on the long arm of chromosome 6. Women with this marker are 1.4 times as likely to get 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