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Biotechnology PowerPoint Presentation
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Biotechnology

Biotechnology

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Biotechnology

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  1. Biotechnology • Techniques used to manipulate DNA • Biotechnology • Many applications: • Medical • Bacterial production of human insulin • Animal science • Bacterial production of BST to increase milk production • Horticultural • Transgenic crops with herbicide resistance or nutrient enhancement

  2. Biotechnology • DNA cleavage • Stages of genetic engineering • Source DNA (with gene of interest) broken into fragments by enzymes • DNA fragments visualized by electrophoresis • Bigger fragments move through gel more slowly when electric current applied

  3. Biotechnology • Production of recombinant DNA • Stages of genetic engineering • DNA fragments inserted into viral or bacterial DNA (=recombinant DNA) • e.g. DNA from source inserted into circular chromosome of bacteria called plasmid

  4. Biotechnology • Cloning • Stages of genetic engineering • Bacteria or virus with source DNA introduced into cells of interest (often bacteria) • Cells reproduce asexually to produce clones • Cells with different fragments maintained separately (produce clone library)

  5. Biotechnology • Screening • Stages of genetic engineering • Clones with DNA fragment of interest (fragment with desired gene) identified • Bacterial plasmid contains gene for antibiotic resistance • Cells without plasmid fragments susceptible to antibiotic STEP 1: remove cells without plasmid

  6. Biotechnology • Screening • Stages of genetic engineering • Clones with DNA fragment of interest (fragment with desired gene) identified • Bacterial plasmid contains gene for enzyme that metabolizes sugar (X-gal) • If source DNA inserted in this gene, no sugar metabolism occurs STEP 2: eliminate cells without source DNA

  7. Biotechnology • Screening • Stages of genetic engineering • Clones with DNA fragment of interest identified • Hybridization used to locate gene of interest Step 3: locate gene of interest

  8. Biotechnology • Produce transgenic plants • Horticultural applications of genetic engineering

  9. ‘Flavr savr’ tomatoes in which ripening is delayed (resist over ripening in transport) Biotechnology • Ethylene inhibition • Horticultural applications of genetic engineering • Carnations insensitive to ethylene last longer when cut

  10. Biotechnology • Herbicide resistance • Horticultural applications of genetic engineering • Transgenic soybeans tolerant to active ingredient in Roundup, a commonly used herbicide • In 1999, 50% of soybeans in US transgenic strains • Used in many other plants (e.g. petunia)

  11. Biotechnology • Nitrogen fixation • Horticultural applications of genetic engineering • Incorporate genes of nitrogen-fixing bacteria into crops to reduce the use of fertilizers Root nodule containing nitrogen-fixing bacteria

  12. Biotechnology • Insect resistance • Horticultural applications of genetic engineering • Incorporate Bt gene into crops • Bt gene produces protein that is toxic when ingested by insect larvae • Approved by EPA for potato, cotton, tobacco, corn, tomato and other crops • Possible detrimental effects on harmless insects such as monarch butterflies

  13. Biotechnology • Added nutrients • Horticultural applications of genetic engineering