Genetics

1
Genetics

• Viruses Bacteria
• Recombinant Technology

2
Viruses

• Contain nucleic acid (DNA or RNA)
• Protein coat called CAPSID, protein subunits
  called CAPSOMERES
• Some have ENVELOPE lipids and proteins from
  host cell

3
Lytic Infection

• Virus penetrates host cell
• Viral genetic material uses host enzymes to
  replicate and produce viral proteins
• Newly assembled viruses erupt from host cell
  (infect new cells)

4
Lytic Infection

• DNA viruses
• Behaves as host DNA
• Utilizes host enzymes
• RNA viruses
• Behave as mRNA (or template)
• Retroviruses reverse transcriptase creates DNA
  copy of RNA to behave as host DNA

5
Lysogenic Infection

• Viral DNA temporarily incorporated into host DNA
  as a PROVIRUS
• Provirus replicated along with host DNA
• Remains inactive until environmental triggers
• Activation leads to lytic cycle

6
Bacteria

• Single, circular DNA
• Naked chromosome no associated proteins (like
  histones)
• Reproduction binary fission
• Plasmids short, circular DNA (beneficial but
  not essential)
• Episomes plasmids that become incorporated into
  genome

7
Genetic Variation in Bacteria

• Conjugation exchange of DNA through pilus
  (genome or plasmid)
• Transduction virus introduces new DNA to
  bacterial genome (virus picked up DNA from
  another bacteria)
• Transformation bacteria absorb DNA from
  surroundings and incorporate into genome

8
Recombinant DNA

• DNA segments or genes from different sources
• Natural transduction, conjugation, transposons,
  crossing over
• Artificial recombinant DNA technology

9
rDNA Technology

• Restriction enzymes from bacteria (defense
  against viruses), cut DNA at specific sequences
• Uneven cuts produce sticky ends
• GOI gene of interest
• Vector method of introducing foreign DNA into
  cell (usually plasmid)
• Transformation - uptake of vector containing GOI

10
cDNA

• Problem GOI contains both exons and introns
  (introns can suppress expression)
• Solution copy DNA from already processed mRNA
  using viral reverse transcriptase
• Called complimentary DNA (cDNA)

11
PCR

• Polymerase Chain Reaction
• Used to amplify DNA (make a LOT of copies of a
  sample)
• Uses DNA polymerase directly (and synthetic
  primers)

12
RFLP Analysis

• Restriction Fragment Length Polymorphisms
• Polymorphism variation in DNA sequences between
  individuals
• Restriction enzymes from bacteria cut DNA
  molecules to create DNA fragments of varying
  lengths
• Separate fragments in gel electrophoresis
• DNA fingerprinting (CSI, paternity)

13
Bozeman DNA Fingerprinting

• DNA Fingerprinting - http//youtu.be/DbR9xMXuK7c
  (610)