Oswald Theodore Avery

• Born: October 21, 1877
• Birthplace: Halifax, Nova Scotia
• Died: February 20, 1955
• Place of death: Nashville, Tennessee

Canadian American molecular biologist

Along with fellow scientists Colin MacLeod and Maclyn McCarty, Oswald Theodore Avery is credited with discovering in 1944 that deoxyribonucleic acid (DNA) is the material that forms the basis for the composition of chromosomes and genes.

Born: October 21, 1877; Halifax, Nova Scotia, Canada

Died: February 2, 1955; Nashville, Tennessee

Primary field: Biology

Specialties: Molecular biology; genetics; cellular biology

Early Life

Oswald Theodore Avery was born in 1877 in Halifax, Nova Scotia. His father, Joseph Avery, was a Baptist minister, and the entire family, which included his mother, Elizabeth, and two brothers, was active in the church. In 1887, the Avery family moved from Halifax to New York City when Joseph accepted a position as pastor at a New York church. Joseph Avery and Oswald’s brother Ernest both passed away in 1892 when Avery was fifteen. Avery attended New York Male Grammar School and then Colgate Academy, the preparatory wing of Colgate University, in upstate New York. Avery was also a talented musician, specializing in the cornet.

In 1900, Avery received a bachelor of arts degree in humanities from Colgate and then entered Columbia University’s College of Physicians and Surgeons in New York City. Avery’s degree in humanities had given him no specific or formal course of training in medicine or science—such as biology or chemistry—prior to enrolling in the College of Physicians and Surgeons; nonetheless, he received his medical degree in 1904. In 1907, Avery began to do laboratory work at Hoagland Laboratory in Brooklyn, which specialized in bacterial research. Avery accepted an assistant directorship there and began to study the origins and causes of infectious diseases. By 1913, Avery had published a study on secondary infections of tuberculosis. This study drew the attention of many, including Rufus Cole, a physician and director of the Rockefeller Institute for Medical Research, a prominent hospital specializing in the biological sciences.

Life’s Work

After joining the Rockefeller Institute in 1913, Avery worked extensively on researching bacterial pneumonia, specifically with respect to determining the various strains of pneumococcus (now called Streptococcus) bacteria present in patients and finding ways to slow their growth. In 1916, Avery and a colleague, Alphonse R. Dochez, published a paper showing that an anti-pneumococcal serum slowed the growth of the bacteria by inhibiting the activity of a certain bacterial enzyme; this presented a new understanding of immunity that they called “antiblastic immunity.” In 1917, following the outbreak of World War I, Avery joined the US Army Medical Corps, where he primarily researched the influenza virus—the culprit in a particularly deadly pandemic starting in 1918—and taught courses on diagnosing respiratory illnesses to Army medical officers. After the war ended, Avery returned to his pneumonia research at the lab at the Rockefeller Institute.

There, Avery began to work on the concept of bacterial transformation. In 1928, another scientist, Frederick Griffith, had discovered that certain strains of pneumococcus could transform into other strains inside of a living being. This groundbreaking discovery was equivalent to realizing that the bacterium could change species. It was discovered that when one strain of live bacteria was injected into mice along with another strain of dead bacteria, the live strain could transform into the dead strain. Avery and his colleagues took notice of this research and set about trying to discover which part of the dead bacteria was effecting the transformation in the live strain.

This research took place in the 1930s and early 1940s. From 1934 to 1937, Avery was debilitated by a thyroid condition called Graves’ disease, and during this time geneticist Colin MacLeod took the lead on the research, which involved breaking down bacterial cells into their component parts over several generations of experiments, to see which part of the cellular material acted as the transforming principle—the genetic material—for live cells. In 1940, MacLeod left the Rockefeller Institute, and in 1941, Maclyn McCarty, another geneticist, joined Avery to continue researching transformation. Avery and McCarty further purified the transforming substance and eventually achieved reliable transformation. Thereafter, Avery and McCarty were able to prove that the bacterial transformation was caused by deoxyribonucleic acid (DNA), despite the widespread scientific belief that a single molecule like DNA could not serve as genetic material, and that something more complex like a protein must be responsible.

In 1944, Avery, MacLeod, and McCarty published their findings in the Journal of Experimental Medicine, in an article called “Studies on the Chemical Nature of the Substance Inducing Transformation of Pneumococcal Types.” Avery included language in the final report expressing a degree of skepticism over the findings, though the research and conclusions were entirely correct.

The length of time necessary to complete the project actually resulted in Avery delaying his retirement. After he was able to retire in 1948, Avery moved to Nashville, Tennessee, to be nearer to his brother Roy, who was a bacteriologist. Avery was diagnosed with liver cancer in 1954 and died the next year at the age of seventy-seven. Avery never married or had children, and he lived several years of his adult life with his friend and colleague Dochez. Though he never won a Nobel Prize for his important work, Avery was a distinguished and well-recognized scholar. He received honorary degrees from several prestigious institutions including the University of Chicago, served as president of the American Association of Immunologists, was awarded the Pasteur Gold Medal from the Swedish Medical Society, and was posthumously elected to the Canadian Medical Hall of Fame in 2004.

Impact

Oswald Avery’s research on DNA was truly groundbreaking. The 1944 report of Avery, MacLeod, and McCarty is regarded by many in the scientific community as the most important work in the field of biology in the twentieth century. In fact, many have suggested that Avery was one of the scientists most deserving of a Nobel Prize. However, he was passed over for the award several times in spite of multiple nominations. There are a few possible reasons why Avery’s important findings failed to result in a Nobel Prize. First, his report was published during World War II, so it would have been more difficult for scientists around the world to read and reflect on Avery’s work. Second, and perhaps more importantly, some scientists simply did not believe Avery’s work when it was published; many refused to believe that DNA, and not protein, was the true genetic material that carried hereditary information, and it was not until Avery retired and was near death that the trio’s conclusion became generally accepted in the scientific community. Finally, the fact that Avery was relatively close to retirement when the report was published could account for part of the reason why he was not viewed as a top candidate for a Nobel Prize, especially when compared to other scientists who were in the prime of their careers, publishing groundbreaking work.

In the decade following the release of the Avery, MacLeod, and McCarty publication, the report was cited several hundred times in scientific journals of note. Additionally, within the first few years following the report, both Avery and McCarty produced articles that expounded on the concepts articulated in the original article, and these articles were well received and widely cited in the scientific community. Moreover, the revelation that DNA is the basis for genes and chromosomes had significant implications for the future of genetics. It formed the basis for famous studies conducted in 1952 by Alfred Hershey and Martha Chase that essentially confirmed the results of the Avery-MacLeod-McCarty experiment, also laying the groundwork for research in microbiology and the study of genetics. Though he never won a Nobel Prize for his body of work, Avery is now regarded as a pioneer with respect to DNA and the field of genetics, and his work paved the way for countless other important discoveries in subsequent decades.

Bibliography

Barry, John M. The Great Influenza: The Story of the Deadliest Pandemic in History. New York: Penguin, 2005. Print. Chronicles the rise of the influenza virus around the world, as well as the efforts of scientists and researchers to confront the epidemic and develop a cure, including detailed information on Avery’s work.

Dubos, Rene´. The Professor, the Institute, and DNA: Oswald T. Avery, His Life and Scientific Achievements. New York: Rockefeller UP, 1976. Print. Delves into both the professional and scientific accomplishments of Avery and the personal recollections of Dubos, who was a student and member of Avery’s lab for more than a decade.

“The Oswald T. Avery Collection.” Profiles in Science. National Library of Medicine, 2008. Web. 26 Apr. 2012. Includes several pages devoted to Avery’s background, a detailed narrative of his scientific work, and links to further readings.