Viral Genetics

Overview

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  • Recombination 
    • exchange of genes between 2 chromosomes
    • crossing over occurs in homologous regions
  • Reassortment   
    • viruses with segmented genomes exchange segments
    • analagous to high-frequency recombination
    • results in influenza pandemics
  • Complementation 
    • 2 viruses infect a cell, but one is mutated and has a non-functional protein
    • the nonmutated virus helps the mutant by making protein for both viruses
  • Phenotypic mixing 
    • 2 viruses infect a cell
    • virus A has its own genetic material, but the surface proteins of virus B
    • progeny viruses contain coat components and genetic material from virus A
      • this is because they only had the genetic material from virus A
    • genetic material is not altered
    • pseudovirion formation
      • when a virus’s coat is entirely from another virus
      • nucleic acid and coat are completely mismatched