Maclyn McCarty

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Maclyn McCarty

Maclyn McCarty with Francis Crick and James Watson
Born June 9, 1911(1911-06-09)
South Bend, Indiana
Died January 2, 2005(2005-01-02) (aged 93)
Known for Role in the discovery that DNA is the carrier of genes

Maclyn McCarty (June 9, 1911 – January 2, 2005) was an American geneticist. He was best known for proving that DNA, rather than protein, was the chemical basis of the gene.

McCarty devoted his life to studying infectious disease organisms. Studies of bacteria led the way to studying heredity through genetics and biochemistry. This started the age of molecular biology.

McCarty was the youngest and longest surviving member of the research team responsible for the Avery-MacLeod-McCarty experiment. He won the Wolf Prize in Medicine for 1990. MacCarty died on January 2, 2005, from congestive heart failure.

The work[change | change source]

The phenomenon was first described in Griffith's experiment of 1928, which suggested DNA was the material of heredity. In this early experiment dead Streptococcus pneumoniae of the virulent strain type III-S, was injected along with living but non-virulent type II-R pneumococci. This resulted in a deadly infection of type III-S pneumococci. This meant the non-virulent strain had been transformed (changed) by something in the dead bacteria.

Work to prove DNA was responsible took many years, starting in 1928. Griffith's work was suggestive, but not sufficient. In their paper of 1944, Avery and his colleagues decided that DNA, rather than protein was the hereditary material of bacteria, and was analogous to genes and/or viruses in higher organisms.[1][2]

This was epoch-making work, but the three men did not get the Nobel Prize. McCarty later explained the work for the general reader.[3]

References[change | change source]

  1. Avery, Oswald T.; Colin M. MacLeod, Maclyn McCarty (1944-02-01). "Studies on the chemical nature of the substance inducing transformation of pneumococcal types: induction of transformation by a Desoxyribonucleic Acid fraction isolated from Pneumococcus Type III". Journal of Experimental Medicine 79 (2): 137–158. doi:10.1084/jem.79.2.137. PMC 2135445. PMID 19871359. http://www.jem.org/cgi/content/abstract/79/2/137. Retrieved 2008-09-29.
  2. Fruton, Joseph S. 1999. Proteins, enzymes, genes: the interplay of chemistry and biology. New Haven, Conn: Yale University Press. 438–440 ISBN 0-300-07608-8
  3. McCarty M. 1985. The transforming principle: discovering that genes are made of DNA. New York: W.W. Norton. ISBN 0-393-30450-7