Elizabeth Blackburn

Lore & Background

Elizabeth Blackburn was born in Hobart, Tasmania, the second of seven children, to family physicians. Her family moved to Launceston when she was four, and later to Melbourne, where she attended University High School. She earned a Bachelor of Science in 1970 and a Master of Science in 1971 from the University of Melbourne, both in biochemistry, then a PhD in 1975 from Darwin College, University of Cambridge, working with Frederick Sanger on DNA sequencing methods and bacteriophage Phi X 174.

During postdoctoral work at Yale, Blackburn studied the protozoan Tetrahymena thermophila and noticed a repeating hexanucleotide sequence (TTAGGG) at chromosome ends. With Jack Szostak, she showed that these sequences protected yeast plasmids from degradation, proving they had telomere characteristics and were evolutionarily conserved. Their work also suggested that the chromosome replication system did not lengthen the telomere, and that the addition of these hexanucleotides was likely due to an enzyme that transfers specific functional groups.

Reader's Guide

Elizabeth Blackburn's co-discovery of telomerase fundamentally changed understanding of cellular aging and chromosome biology. By identifying the enzyme that replenishes telomeres, she solved a long-standing puzzle in molecular biology: how chromosomes maintain their ends during replication. This work has profound implications for aging research, as telomerase activity is linked to cellular lifespan, and for cancer biology, where the enzyme is often reactivated in tumor cells. Her research also opened new avenues for studying diseases such as pancreatic, bone, prostate, bladder, lung, kidney, and head and neck cancers. Beyond her scientific contributions, Blackburn's dismissal from the President's Council on Bioethics highlighted tensions between scientific advice and political policy, sparking widespread support from the scientific community. Her leadership at the Salk Institute and her role as the first Australian woman Nobel laureate underscore her lasting impact on both science and public discourse.

Did You Know?

• Blackburn co-discovered telomerase in 1984 with Carol W. Greider.
• She was the first Australian woman to win a Nobel Prize.
• She was dismissed from the President's Council on Bioethics in 2004, leading 170 scientists to sign an open letter in her support.
• Blackburn co-founded the company Telomere Health but later severed ties with it.

The Discovery of Telomerase

While conducting postdoctoral research at Yale, Blackburn was examining the protozoan Tetrahymena thermophila and noticed something remarkable: a repeating hexanucleotide sequence at the very tips of its linear chromosomes. The TTAGGG pattern was tandemly repeated, and the terminal ends formed palindromic structures. Working alongside Jack Szostak, she demonstrated that these sequences shielded unstable yeast plasmids from degradation, confirming they carried the hallmarks of telomeres and were conserved across species. A critical puzzle emerged: the standard DNA replication machinery could not account for the addition of these terminal repeats, suggesting an unknown enzyme must be responsible. This hypothesis led her and her doctoral student Carol Greider to identify, in 1985, an enzyme possessing reverse transcriptase activity that could extend the 3' overhang of telomeric DNA. Once purified in the laboratory, the enzyme revealed a dual composition—RNA serving as a template for repeat addition and protein providing the catalytic machinery. They named it telomerase, and in doing so resolved the end-replication problem that had long perplexed the field.

Nobel Recognition and Academic Career

In 2009, Blackburn shared the Nobel Prize in Physiology or Medicine with Carol Greider and Jack Szostak for their collective work on telomeres and telomerase. The award made her the first Australian woman to receive a Nobel Prize, a milestone that underscored the global reach of her contributions. Her academic trajectory reflected steady institutional commitment: after joining the faculty at the University of California, Berkeley in 1978, she crossed the bay to UCSF in 1990, where she chaired the Department of Microbiology and Immunology from 1993 to 1999 and held the Morris Herzstein Professorship in Biology and Physiology. She retired to Professor Emeritus status at the close of 2015. Beyond the laboratory, she served as president of the Salk Institute for Biological Studies and co-founded Telomere Health, a company offering telomere-length assessments. In a 2016 interview she recalled the quiet moment in the lab when she and Greider stared at an autoradiogram and recognized a regular, non-random pattern—what she described as something real shining through the data, prompting the rigorous verification that followed.

From Tasmania to Cambridge

Elizabeth Helen Blackburn entered the world on 26 November 1948 in Hobart, Tasmania, as the second of seven children born to two family physicians. The family relocated to Launceston when she was four, and she spent her secondary years at Broadland House, a Church of England girls' grammar school that later merged with Launceston Church Grammar School. A subsequent move to Melbourne placed her at University High School, where she posted exceptionally high scores in the statewide matriculation examinations. She then pursued biochemistry at the University of Melbourne, earning a Bachelor of Science in 1970 and a Master of Science in 1972. Her doctoral work took her to Darwin College at the University of Cambridge, where, under the supervision of Frederick Sanger at the MRC Laboratory of Molecular Biology, she helped develop methods for sequencing DNA using RNA probes and studied the bacteriophage Phi X 174. She completed her PhD in 1975, having already built the molecular-biology foundation on which her later telomere research would rest.

Ethics, Controversy, and the Public Arena

Blackburn's influence extended well beyond the bench. She engaged actively in medical ethics, a path that brought her into the political sphere when she was appointed to the President's Council on Bioethics during the George W. Bush administration. Her tenure there proved short-lived and contentious: she was dismissed in a manner that drew widespread criticism from the scientific community. In response, one hundred and seventy scientists signed an open letter addressed directly to the president, arguing that her removal was motivated by political disagreement with the advice she had offered rather than by any professional failing. The episode highlighted the tension between independent scientific counsel and executive authority, and it cemented Blackburn's reputation as a researcher willing to speak publicly on matters of bioethical importance. Her career thus spans two distinct arenas—the molecular laboratory and the policy table—where she has consistently championed evidence-based reasoning and the integrity of scientific judgment in the face of institutional pressure.