Genetic Technologies

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Genetic Technologies

• By Ting-Yu Tsai
• Han Keyl Kim

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19.1 Patenting DNA

• Biotechnology
• -Use or alteration of cells or biological
  molecules for specific applications.
• Organisms that harbor DNA from other species are
  termed Transgenic and their DNA is called
  recombinant DNA

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The OncoMouse or Harvard mouse is a type of
laboratory mouse that has been genetically
modified using modifications designed by Philip
Leder and Timothy A. Stewart of Harvard
University to carry a specific gene called an
activated oncogene. The activated oncogene
significantly increases the mouses
susceptibility to cancer, and thus makes the
mouse suitable for cancer research. The rights to
the invention are owned by DuPont. OncoMouse(R)
is a registered trademark.
Patented OncoMouse
The Laboratory, or The Passion of OncoMouse
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Key Concept

• Biotechnology is the use of modification of cells
  or biological molecules for a specific
  application.
• Patent law regarding DNA has evolved with the
  technology since the 1970s, and is still changing.

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19.2 Amplifying DNA PCR

• Polymerase Chain Reaction (PCR) are the
  technologies for amplified DNA that invented by
  Kary Mullis in 1983. He then won the Nobel prize
  for PCR in 1993.
• Use of PCR
• - DNA cloning for sequencing
• - DNA-based phylogeny
• - Diagnosis of hereditary diseases
• - Functional analysis of genes
• - Identification of genetic fingerprints
• - Detection and diagnosis of infectious
  diseases

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PCR STEPS

• Initialization Heating the reaction to 94-96C.
  Its only required for DNA polymerases.
• Denaturation First regular cycling. Heat for
  separate 2 strands of the target DNA.
• Annealing 2 short primers and Taq1 DNA
  polymerase added. Cool to allow primers form
  hydrogen bond with ends of target sequence.
• Extension DNA polymerase adds nucleotides to the
  3 end of each primer.
• Final elongation This step is to ensure that
  any remaining single-stranded DNA is fully
  extended.
• Final hold May be employed for short-term
  storage of the reaction.

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19.3 Modifying DNA

• Modifying DNA
• -Researchers thought about uses and risks of
  mixing DNA from different species.
• -Recombinant DNA technology was safer than
  expected, and the technology has spread to
  industry more swiftly and in more diverse ways.

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Cloning vectors

• Plasmid
• Bacteriophage
• Bacterial artificial
• Chromosome (BAC)
• Yeast artificial
• Chromosome (YAC)

Size of insert accepted up to 15
Size of insert accepted up to 90
Size of insert accepted 100 to 500
Size of insert accepted up to 15
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• Genomic library a population of host bacteria,
  each of which carries a DNA molecule that was
  inserted into a cloning vector, such that the
  collection of cloned DNA molecules represents the
  entire genome of the source organism. This term
  also represents the collection of all of the
  vector molecules, each carrying a piece of the
  chromosomal DNA of the organism, prior to the
  insertion of these molecules into the host cells.
  
• DNA probe a single-stranded DNA molecule used in
  laboratory experiments to detect the presence of
  a complementary sequence among a mixture of other
  singled-stranded DNA molecules.
• cDNA library is a collection of cloned cDNA
  (complementary DNA) fragments inserted into a
  collection of host cells, which together
  constitute some portion of the transcriptome of
  the organism. cDNA is produced from fully
  transcribed mRNA found in the nucleus and
  therefore contains only the expressed genes of an
  organism. Similarly, tissue specific cDNA
  libraries can be produced. In eukaryotic cells
  the mature mRNA is already spliced, hence the
  cDNA produced lacks introns and can be readily
  expressed in a bacterial cell. While information
  in cDNA libraries is a powerful and useful tool
  since gene products are easily identified, the
  libraries lack information about enhancers,
  introns, and other regulatory elements found in a
  genomic DNA library.

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Transgenic Plants

• Transgenic plants are easier to create than
  transgenic animals because plants can be derived
  from somatic cells.
• Protoplasts The denude plant cells had their
  cell walls removed by some manipulations.

• Protoplasts

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Ti Plasmid

• Ti plasmid is a circular plasmid that is a part
  of the genetic equipments that Agrobacterium
  tumefaciens use to transduce its genetic material
  to plants. It normally causes a tumor-like
  growth.

• Producing a transgenic plant

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Bacillus Thuringiensis

• Bt is a soil-dwelling bacterium that commonly
  used as a pesticide.
• When bt gene is bring into corn cells via a Ti
  plasmid, the cells regenerate corn plants and
  produce their own insecticide.
• Possible problems The pollen form Bt maize could
  kill the monarch butterfly.

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References

• http//en.wikipedia.org/wiki/Polymerase_chain_reac
  tion
• Chapter 19 Genetic Technologies, Human Genetics
  8th Edition, McGraw-Hill Companies, Ricki Lewis,
  2008.
• http//www.everythingbio.com/
• http//scienceblogs.com/insolence/2007/06/the_auti
  sm_omnibus_the_difference_betwee.php
• http//www.biology.lsu.edu/webfac/nkato/methods/me
  thodImages/Protoplast.jpg
• http//www.mun.ca/biology/desmid/brian/BIOL2060/BI
  OL2060-20/2032.jpg
• http//en.wikipedia.org/wiki/Bacillus_thuringiensi
  s