Vectors in Genetic Engineering

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Vectors in Genetic Engineering

• Jennifer Miller
• April 18, 2003
• ABE 4660

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What are Vectors?

• Small independently replicating gene elements
• Present a way to introduce foreign DNA into a
  cell
• Examples are plasmids, bacteriophage lambda, and
  cosmids

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DNA Uptake by Bacteria

• Transduction
• Transformation
• Conjugation

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Plasmids

• Circular strands of DNA, that are independent of
  cells genome.
• Independent replication
• Gene markers, such as antibiotic resistance.
• Example pBR322 in E. coli

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Plasmid Insertion
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Bacteriophage Lambda

• Can accommodate large pieces of DNA
• Greater efficiency transmission rate is near
  100 compared to 0.1 for plasmid.
• Useful for constructing cDNA libraries and
  genomes.

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Ti Plasmid

• Involves the transfer of DNA from a bacteria into
  a plant cell.
• Microorganisms Agrobacterium tumefaciens
• Only virulence (vir) region is inserted
• Leads to transgenic plants

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Cosmids

• Type of Plasmid vector that has cohesive (cos)
  sites
• Can be packaged into a bacteriophage
• Becomes a large plasmid
• Can assist in insertion of 35-45 kilobases
• Importance to biotechnology

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Applications

• A Food-Grade Approach for Functional Analysis
  and Modification of Native Plasmids in
  Lactococcus lactis.
• Cooperation Between Lactococcus lactis and
  Nonstarter Lactobacilli in the Formation of
  Cheese Aroma from Amino Acids

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Lactococcus and Lactobacilli

• Lactococcus
• Important in the dairy industry
• Part of starter culture
• Lactobacillus
• Nonstarter bacilli
• Responsible for the rich flavor in cheese
• Has the enzyme glutamate dehydrogenase (GDH)

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Food Grade Plasmid

• 2 separate plasmids
• A heat sensitive plasmid that has an antibiotic
  marker
• One that carries the gene of interest
• Biotechnology Possibilities

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Questions?