Transgenesis

• Transgenesis

  The process of making a transgenic organism or GM (genetically modified) organism
• Making a Transgenic Crop (1-3)

  1. Bacteria is treated with heat to make it take up the recombinant plasmid in a process called transformation
  2. Plant cells are extracted and exposed to the GM bacteria in a petri dish
  3. Agrobacterium inserts target gene into the DNA of the plant cell - agrobacterium acts as a vector (transports the target gene into the plant's DNA)
• Making a Transgenic Crop (4-5)

  4. GM plant cells are grown in a culture

  5. A plant is grown from the GM plant cells, resulting in a GM plant with all cells of the plant containing the target gene expressed in their phenotype
• Benefits of Transgenic Organisms in Agriculture (Herbicide Resistant Crops)

  • herbicide resistant gene occurs naturally in a species of soil bacteria - transferred to a crop to give it resistance to a herbicide
  • eg. Roundup Ready
  • broader spectrum of weeds controlled
  • reduce crop injury
• Pest Resistant Crops (Bt Cotton)

  • soil bacterium produces toxins that are poisonous to some insects
  • gene is taken from the soil bacterium and inserted into cotton to make it naturally produce the tozen in its leaves - when insects eat the crop, they die
  • saves cost of applying insecticides
  • prevents loss of crop yield to pests
• Disease Resistant Crops

  • stem rust is a disease that's treated by spraying plants with fungicides - however, pathogens that cause stem rust can develop resistance to fungicides
  • reduces use of insecticides
  • cuts farming cost
• Tolerance to Adverse Conditions

  Some crops have been genetically altered to make them more tolerant to conditions like salinity, cold, and drought
• Greater Yield

  • transplanted genes from cyanobacteria genes allow the plant to produce a more efficient enzyme for converting CO2 into sugars and other carbs (faster photosynthesis)
  • resistance to pests or tolerance to adverse condition increase crop yield
• Improved Product Quality

  • improved colour, smell, size of flowers
  • shelf life of tomatoes
  • non browning apples
  • inclusion of vitamins in food (eg. golden rice with vitamin A)
• Animal Ethics

  • reduction: using fewer amount of animals
  • refinement: minimising pain and distress, enhancing animal wellbeing
  • replacement: use of non-sentient animals or animals with lower sentient value