Biotechnology by 9B9ojQ4

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									Biotechnology - traditional
   Modification by microorganisms of
    materials for human use
   Use of biological organisms in agriculture
    and industrial processes
    – Fermentation of fruit juice into wine, grains
      into beer
    – Conversion of milk into cheese, yogurt
    – Production of bread
    – Sewage and solid waste treatment
    – Production of antibiotics
Biotechnology - today
   Molecular techniques now used
   Use of recombinant DNA technology to
    alter the heredity of organisms.

   DNA recombination: insertion of foreign
    DNA into existing DNA (not sexual).

   Transformed organism: foreign DNA has
    become permanent part of genome.
DNA recombination
   Selection and insertion of genes from a
    different organism, in vitro
   Transformation or organism is more rapid
    and efficient that traditional breeding
    techniques.
DNA recombination
   If foreign gene inserted into
    genome:
    Genetically Engineered Plant

   If inserted gene is from
    another species:
    Transgenic Plant
Transformation Process
1.   Locate and identify gene
     for desired trait
     – Most limiting step
     – Must sequence sections of DNA
     – Determine what segments are of interest
2.   Isolate gene from rest of DNA
     – Cut strand and piece back together again
Transformation Process
3.   Insert gene into plant cell and
     use tissue culture to propagate
     –   Agrobacterium transforms plant
         tissue to produce new DNA
         (dicots)
     –   Gene gun: gold particles coated
         with gene blasted into plant
         tissue. Penetrates cell wall.
         (monocots)
Transformation Process
4.   Screen plant material for presence of
     new gene
     – Inserted gene usually has additional
       antibiotic resistance attached
     – Screen on culture medium that contains
       antibiotic
     – Tissues with desired gene will be resistant
       and not die
Applications of biotechnology
   Plants as living factories: molecular
    farming
    – Plants are genetically modified to produce
      certain chemicals
    – Usually for pharmaceutical use: “pharming”
    – Superior to mammalian production b/c free
      of animal pathogens, not hosts of agents
      that may cause human disease
Applications of biotechnology
   Vaccine delivery
    – Plant produces disease gene
    – Plant is consumed to impart vaccine orally
    – (must be raw b/c cooking destroys immunological
      properties)
    – Cheaper than yeast or other microbial production
      (require expensive facilities)
    – Still being developed
Applications of biotechnology
   Herbicide resistance
    – Plants are transformed to not be susceptible to
      herbicide
    – Kill weeds with herbicides, avoid injury to crop
    – Roundup™-Ready Soybeans
    – More than half of total soybean acreage in US
      and Canada
    – (Roundup halts a.a. synthesis in a pathway
      that exists only in plants; little residual in soil)
Applications of biotechnology
   Herbicide resistance, cont.
    – Increased use of herbicide can result in herbicide-
      resistant weeds
    – Decrease amount of herbicides used, move away
      from more harmful herbicides
Applications of biotechnology
   Insect resistance
    – Bt corn and cotton: StarLink
    – Plant produces toxin made by Bacillus
      thuringiensis
    – Kills Lepidopteran larvae that feed on the
      resistant crop
    – Crops used for animal feed only
    – Bt sprays used by organic farmers, home
      gardeners
Applications of biotechnology
   Insect resistance, cont.
    – Does not affect humans due to differences in
      digestive tract
          lack receptors in gut lining
          Humans acidic; insects alkaline
    – Insect biodiversity higher than when treated with
      traditional chemicals
    – Minimal pollen transfer during monarch feeding
      periods
Applications of biotechnology
   Yield properties
    – Ripening (tomato)
          FlavrSavr: ripening without softening
          Yield, flavor, disease were problems
    – Oil production (canola)
    – Nutritional value
          Increase protein in sweet potatoes
          Increase beta-carotene in rice
   Virus resistance
    – Tomato, potato
   Environmental tolerances

								
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