DNA/Timelines

1866: Gregor Mendel identifies inheritance "factors" in pea plants. 1869: Friedrich Miescher isolates “nuclein” (DNA) from infected wounds. 1900: Karl Correns, Hugo de Vries and Erich von Tschermak independently rediscover Mendel's laws. 1910: Thomas Hunt Morgan proposed a theory of sex-linked inheritance for the first mutation discovered in the fruit fly, Drosophila, white eye. 1913: Morgan and Alfred Sturtevant propose principle of gene linkage leading to the first genetic map. 1927: Hermann J. Muller Used x-rays to cause artificial gene mutations in Drosophila. 1928: Frederick Griffith demonstrates a "transforming factor" that can transmit the ability of bacteria to cause pneumonia in mice. 1929: Phoebus Levene describes building blocks of DNA, including four types of base A,C, T, and G. 1931: Harriet Creighton and Barbara McClintock Demonstrated the cytological proof for crossing-over in maize. 1941: George Beadle and Edward Tatum prove that a gene can produce its effect by regulating particular enzymes. 1944: Oswald Avery, Colin MacLeod, and Maclyn McCarty purified the transforming factor proposed in Griffith's experiment and show it is not protein, but DNA. Late 1940s: Barbara McClintock developed the hypothesis of transposable elements. 1950: Alfred Hershey and Martha Chase use bacteriophage to confirm DNA is the molecule of heredity. Erwin Chargaff discovered a one-to-one ratio of A:T and G:C in DNA samples from a variety of organisms. 1951: Rosalind Franklin created a high quality X-ray diffraction photograph to reveal more detail of the repeating structure of DNA. 1953: Francis Crick and James Watson deduce the three-dimensional structure of the DNA molecule using a combination of experimental data and model building. 1958 Arthur Kornberg purified a DNA polymerase from bacteria, and used it to synthesis DNA in a test tube. Matthew Meselson and Franklin Stahl demonstrated that DNA replicates by a semi-conservative mechanism. 1966: Marshall Nirenberg and Gobind Khorana crack the genetic code linking the DNA sequence of nucleotides to the protein sequence of amino acid residues. 1967: Discovery of DNA ligase. 1969: FISH 1970: Howard Temin discovered the of activity of reverse transcriptase. Hamilton Smith and Kent Wilcox isolated the first restriction enzyme, HindII, that cuts DNA at a very specific nucleotide sequence. 1972: Paul Berg creates the first recombinant DNA molecules, using restriction enzymes. This technology will be the beginning of the biotechnology industry. 1973: Annie Chang and Stanley Cohen showed that a recombinant DNA molecule can be maintained and replicated in E. coli. Joseph Sambrook refined DNA electrophoresis (first described in 1953) by using an agarose gel and staining the DNA with ethidium bromide. 1975: An International meeting at Asilomar, California provided guidelines regulating recombinant DNA experimentation. Ed Southern developed the Southern blot for DNA. This name inspires similar blotting techniques for RNA (northern blot) and protein (western blot). 1976: Herbert Boyer cofounds Genentech, the first firm founded in the United States to apply recombinant DNA technology 1977: Frederick Sanger, Allan Maxam, and Walter Gilbert developed the chain termination (dideoxy) method for sequencing DNA. 1978: Somatostatin, which regulates human growth hormones, is the first human protein made using recombinant technology. 1980: Mark Skolnick, Ray White, David Botstein, and Ronald Davis create RFLP marker map of human genome. 1981: Three independent research teams announced the discovery of human oncogenes (cancer genes). 1983: James Gusella demonstrate that the Huntington's disease gene is on chromosome 4. 1985: Kary Mullis published a paper describing the polymerase chain reaction (PCR) a technique to amplify specific DNA sequences from minutes quantities of starting material. Alec Jeffreys devised a technique that uses DNA polymorphisms to distinguish between different individuals. He later coined the term DNA fingerprinting and this is now impotant for many paternity, immigration, and murder cases. 1986: Leroy Hood and Lloyd Smith automate DNA sequencing with the goal of sequencing whole genomes. 1987: US DOE officially begins human genome project. 1990: BLAST algorithm developed to align DNA sequences and is the key to comparative genomics. The first occurance of gene replacement therapy to repair a defective ADA gene in a four year old girls T-cells. 1993: FlavrSavr tomatoes are the first genetically modified organisms to be marketed. They were engineered to ripen more slowly for longer shelf life. 1995: Patrick Brown and Stanford University colleagues invent DNA microarray technology. Researchers at The Institute for Genomic Research publish first genome sequence of free-living organism: Haemophilus influenzae. 1998: NIH begins the Single Nucleotide Polymorphism (SNP) project to reveal human genetic variation. 1999: First human chromosome sequence published. 2000: Fruit fly genome sequenced using Celera’s whole-genome shotgun method. 2001: Science and Nature publish annotations and analyses of human genome. 2005: HapMap published giving a huge resource of SNP's and information relating to human variation.