What is genetic engineering??

Biotechnology today Genetic Engineering Our tool kit… manipulation of DNA if you are going to engineer DNA & genes & organisms, then you need a set of tools to work with Here are some of our tools Our tool kit…

Bacteria Bacteria review one-celled prokaryotes reproduce by mitosis binary fission rapid growth generation every ~20 minutes 108 (100 million) colony overnight! dominant form of life on Earth incredibly diverse

Bacterial genome Single circular chromosome haploid naked DNA no histone proteins ~4 million base pairs ~4300 genes 1/1000 DNA in eukaryote Genome = all the DNA of an organism Eukaryotes • 1000 times more DNA • only 10 times more genes - introns, spacers, inefficiency How have these little guys gotten to be so diverse??

Plasmids Small supplemental circles of DNA carry extra genes 5000 - 20,000 base pairs self-replicating carry extra genes 2-30 genes genes for antibiotic resistance can be exchanged between bacteria bacterial sex!! rapid evolution can be imported from environment Mini-chromosomes

How can plasmids help us? A way to get genes into bacteria easily insert new gene into plasmid insert plasmid (vector) into bacteria bacteria now expresses new gene bacteria make new protein transformed bacteria gene from other organism recombinant plasmid vector plasmid cut DNA + glue DNA

Biotechnology Plasmids used to insert new genes into bacteria cut DNA gene we want like what? …insulin …HGH …lactase cut plasmid DNA Cut DNA? DNA scissors? ligase insert “gene we want” into plasmid... “glue” together recombinant plasmid

Restriction enzymes Action of enzyme Many different enzymes Madam I’m Adam Action of enzyme cut DNA at specific sequences restriction site symmetrical “palindrome” produces protruding ends sticky ends will bind to any complementary DNA Many different enzymes  CTGAATTCCG GACTTAAGGC  CTG|AATTCCG GACTTAA|GGC

Grow bacteria…make more transformed bacteria gene from other organism + recombinant plasmid vector plasmid grow bacteria harvest (purify) protein

Uses of genetic engineering Genetically modified organisms (GMO) Agriculture: Insert new genes enabling plants to produce new proteins Drugs: “Pharming” Production of human insulin by bacteria “Fixing” mutated genes in humans: Adding correct copies of mutated genes to people For example, a transgenic rice plant has been developed that produces yellow grains containing beta-carotene. Humans use beta-carotene to make vitamin A. Currently, 70% of children under the age of 5 in Southeast Asia are deficient in vitamin A, leading to vision impairment and increased disease rates.

Uses of genetic engineering Genetically modified organisms (GMO) Agriculture: Insert new genes enabling plants to produce new proteins Protect crops from insects: BT corn corn with a gene from bacteria that produces a toxin which kills corn borer (caterpillar pest of corn) Extend growing season: fishberries strawberries with a gene for an antifreeze protein from flounder Improve quality of food: golden rice rice with gene for Vitamin A -producing vitamin A improves nutritional value For example, a transgenic rice plant has been developed that produces yellow grains containing beta-carotene. Humans use beta-carotene to make vitamin A. Currently, 70% of children under the age of 5 in Southeast Asia are deficient in vitamin A, leading to vision impairment and increased disease rates.

Your Task: Genetically Modified Foods: Blessing or Curse??? You have assignment, rubric and source materials. You will produce a Poster addressing the questions from the assignment. Due Friday, Feb 24.