DNA Timeline

  • DNA is founded.

    DNA is in the shape of a double helix with antiparallel nucleotide chains and specific base pairing.
  • DNA replication is semi-conservative.

  • Messenger RNA is the intermediate between DNA and protein.

  • The genetic code is cracked by a number of researchers using RNA homopolymer and heteropolymer experiments as well as tRNA labeling experiments.

  • The first restriction enzyme is purified by Hamilton Smith.

  • Period: to

    Recombinant DNA is first constructed by Cohen and Boyer.

  • DNA sequencing technology is developed by Fred Sanger.

  • PCR is developed by Kary Mullis.

  • Period: to

    Genome projects are begun.

  • Period: to

    DNA microarrays are invented by Pat Brown and colleagues.

  • Automated sequencing technology allows genome projects to accelerate.

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    The first cloning of a mammal (Dolly the sheep) is performed by Ian Wilmut and colleagues, from the Roslin institute in Scotland.

  • The Drosophila genome is completed. The Arabidopsis genome is completed. The human genome is reported to be completed.

  • The sequence of the human genome is released, and the "post-genomic era" officially begins.

  • Controversies continue over human and animal cloning, research on stem cells, and genetic modification of crops.