Brenner, Sydney (1927-), a South African molecular biologist and geneticist, ranks as one of the founders of the field of molecular biology. He shared the 2002 Nobel Prize in physiology or medicine for his research on how genes control the growth and development of organisms.

Brenner earned a master's degree from the University of Witwatersrand in Johannesburg, South Africa, in 1947, and a doctorate from Oxford University in England in 1954. He returned to Johannesburg in 1955 to teach physiology at Witwaters-rand. In 1957, he joined the research staff of the Medical Research Council's Laboratory of Molecular Biology in Cambridge, England, and later became director of the council's Unit of Molecular Genetics

In 1961, Brenner and his colleagues discovered messenger RNA (mRNA), a substance that carries the instructions for making proteins in a cell. That year, he and genetics pioneer Francis H. C. Crick confirmed his theory on the structure of genetic code, which is the sequence of chemical units that determines the function of DNA and RNA molecules. They showed that genetic code is made up of groups of three chemical units called triplets and that each triplet does not share a chemical unit with another triplet.

In 1963, Brenner used a worm, Caenorhabditis elegans, as a research organism. He and his associates mapped the worm's nervous system and tracked every stage of its development on a cellular level. Brenner also mapped the worm's genes. His genetics work with C. elegans has become a model program for other researchers. In 1996, he founded the Molecular Sciences Institute, a private research organization in La Jolla, California. It moved to Berkeley, California, in 1998.

Brenner shared the 2002 Nobel Prize with H. Robert Horvitz of the United States and John E. Sulston of Great Britain. The three biologists conducted research on the development, growth, and cell death of tiny roundworms called nematodes.