1950
1955
1960
1953 James Watson and Francis Crick model the DNA double helix structure. Their research was based, in part, on X-ray crystallography experiments by Rosalind Franklin.
1959 UC Davis biologists RALPH STOCKING and ERNEST GIFFORD show that plant chloroplasts, which carry out photosynthesis in plant cells, have their own DNA, separate from the nucleus.
1965 1966 ROBERT W. HOLLEY, MARSHALL NIRENBERG and HAR GOBIND KHORANA
determine genetic code.
FROM DNA
ROSALIND FRANKLIN
JAMES WATSON
FRANCIS CRICK
UC DAVIS HAS CONTRIBUTED
1970
RALPH STOCKING
TO
ERNEST GIFFORD
1972 SUSUMO OHNO coins term “junk DNA” for DNA sequences without an obvious (at the time) function.
G EN OM ES
ROBERT W. HOLLEY
MARSHALL NIRENBERG
HAR GOBIND KHORANA
significantly to genomic and DNA science since its beginnings. Some highlights are picked out
in blue in this timeline. From Ralph Stocking and Ernest Gifford showing that plant chloroplasts have their own DNA, to Carl Schmid’s work on so-called “junk” DNA, to contributing to the sequencing of species including cucumbers, chickens, horses and wheat, the breadth of expertise on campus makes UC Davis uniquely placed to apply this new technology.
all the genetic material of an organism. While classical genetics zooms in on individual genes, genomics pulls back the focus, allowing scientists to see all the genes of an organism at the same time, then to comb through them for trends, associations and interactions. If genetics were baseball, the classical approach would be to know all about a single player. Genomics, on the other hand, means knowing something about all the players in every team in the league. “We used to be limited by the amount of data, and that’s no longer the case. The limiting step in science now is adding knowledge that adds value to the data,” said Richard Michelmore, director of the UC Davis Genome Center. At UC Davis, genomics is now being used to study crops like tomatoes, peppers and wheat; search for clues to cancer and autism; find ways to make new green fuels; and understand the microbes that live in, on and around us and make
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us healthy or sick. “At UC Davis, we are very well placed to exploit the genome revolution because we study everything here. We have probably the largest, certainly the most diverse collection of biologists in the world,” Michelmore said.
A SHORT HISTORY Sixty years ago last February, Francis Crick announced to a crowded Cambridge pub that he and James Watson had discovered the “secret of life”—the double helix structure of DNA, the molecule that carries genetic information from generation to generation. Watson and Crick’s double helix showed how the four molecules at the heart of DNA—adenine, guanine, cytosine and thymine, or A, G, C and T—can pair up: A with T, G with C. This meant, they realized, that any stretch of DNA could be copied and duplicated. Over the next 30 years, molecular
biologists learned how to identify and sequence stretches of DNA coding for genes for particular traits, and transferred snippets into other organisms to study them or to develop new breeds and products. This recombinant DNA technology is now widely used to make medicines and vaccines, as well as for new varieties of crops such as corn, cotton and soybeans. But these efforts dealt with relatively small pieces of DNA. In 1990, the U.S. Department of Energy and the National Institutes of Health formally launched the Human Genome Project, an international effort led by the U.S. to determine the complete sequence of DNA of a human being—about 3 billion letters of DNA code. Enter J. Craig Venter, an entrepreneurial biologist who believed genome sequencing would move faster with a different technical approach that became known as “shotgun sequencing.” He