Unit 3 – Genetics

1. Unit 3 – Genetics • Chapter 20~ DNA Technology & Genomics

2. O.J. Simpson capital murder case,1/95-9/95 • Odds of blood in Ford Bronco not being R. Goldman’s: • 6.5 billion to 1 • Odds of blood on socks in bedroom not being N. Brown-Simpson’s: • 8.5 billion to 1 • Odds of blood on glove not being from R. Goldman, N. Brown-Simpson, and O.J. Simpson: • 21.5 billion to 1 • Number of people on planet earth: • 6.1 billion • Odds of being struck by lightning in the U.S.: • 2.8 million to 1 • Odds of winning the Illinois Big Game lottery: • 76 million to 1 • Odds of getting killed driving to the gas station to buy a lottery ticket • 4.5 million to 1 • Odds of seeing 3 albino deer at the same time: • 85 million to 1 • Odds of having quintuplets: • 85 million to 1 • Odds of being struck by a meteorite: • 10 trillion to 1

3. Recombinant DNA • Def: DNA in which genes from 2 different sources are linked • Genetic engineering: direct manipulation of genes for practical purposes • Biotechnology: manipulation of organisms or their components to perform practical tasks or provide useful products

4. Bacterial plasmids in gene cloning

5. DNA Cloning • Restriction enzymes (endonucleases): in nature, these enzymes protect bacteria from intruding DNA; they cut up the DNA (restriction); very specific • Restriction site: recognition sequence for a particular restriction enzyme • Restriction fragments: segments of DNA cut by restriction enzymes in a reproducable way • Sticky end: short extensions of restriction fragments • DNA ligase: enzyme that can join the sticky ends of DNA fragments • Cloning vector: DNA molecule that can carry foreign DNA into a cell and replicate there (usually bacterial plasmids)

6. Steps for eukaryotic gene cloning • Isolation of cloning vector (bacterial plasmid) & gene-source DNA (gene of interest) • Insertion of gene-source DNA into the cloning vector using the same restriction enzyme; bind the fragmented DNA with DNA ligase • Introduction of cloning vector into cells (transformation by bacterial cells) • Cloning of cells (and foreign genes) • Identification of cell clones carrying the gene of interest

7. DNA Analysis & Genomics • PCR (polymerase chain reaction) • Gel electrophoresis • Restriction fragment analysis (RFLPs) • Southern blotting • DNA sequencing • Human genomeproject

8. Polymerase chain reaction (PCR) • Amplification of any piece of DNA without cells (in vitro) • Materials: heat, DNA polymerase, nucleotides, single-stranded DNA primers • Applications: fossils, forensics, prenatal diagnosis, etc.

9. DNA Analysis • Gel electrophoresis: separates nucleic acids or proteins on the basis of size or electrical charge creating DNA bands of the same length

10. Restriction fragment analysis • Restriction fragment length polymorphisms (RFLPs) • Southern blotting: process that reveals sequences and the RFLPs in a DNA sequence • DNA Fingerprinting

11. DNA Sequencing • Determination of nucleotide sequences (Sanger method, sequencing machine) • Genomics: the study of genomes based on DNA sequences • Human Genome Project

12. Practical DNA Technology Uses • Diagnosis of disease • Human gene therapy • Pharmaceutical products (vaccines) • Forensics • Animal husbandry (transgenic organisms) • Genetic engineering in plants • Ethical concerns?