Elizabeth Blackburn and the Story of Telomeres: Deciphering the Ends of DNA

  • Catherine Brady
MIT Press: 2007. 424 pp. $29.95/£19.95 9780262026222 | ISBN: 978-0-2620-2622-2
Arm arrangement: Liz Blackburn, discoverer of telomeres and telomerase, in her laboratory. Credit: E. FALL

“I want to understand how living things work,” declared a young Liz Blackburn to Frank Hird, her supervisor at the University of Melbourne, when asked why she wished to pursue a scientific career. Back in the 1960s, Blackburn could not have imagined that she would later be the main player in two fundamental discoveries in biology: the molecular nature of the ends of chromosomes, or telomeres, and the identification of the enzyme telomerase.

Catherine Brady's biography is a page-turner from the first chapter, weaving together the heroine's personality with her success as a scientist. We learn about Blackburn's family and her first tentative steps in the science world that eventually led to the discovery of telomerase in the mid-1980s, and about her determination, her curiosity, her way of dealing with situations and her opinions on the peer-reviewing process.

In highlighting the factors that shaped Blackburn's career, we follow her incursions into policy-making and science ethics: first as president of the American Society of Cell Biology (ASCB) and as the chair of the Department of Microbiology and Immunology at the University of California in San Francisco (UCSF), and then as part of the Bioethics Advisory Council to President George W. Bush — from which she was dismissed for her views on stem-cell policy.

Blackburn has been an inspiration to those of us who started out in the field of telomeres. The book conveys a vivid impression of her that matches a personal encounter. Her equable temperament does not prevent her from having strong views, and she emerges as a valuable role model in the sometimes unsettling treatment of women in the world of science.

Born the second daughter of seven children in Tasmania, Australia, to a family of professional scientists (her parents were medical practitioners and her grandfather and great-grandfather were geologists in China). An early interest in chemistry and biochemistry propelled her to Hird's lab for her doctorate, which matured her forceful scientific mind and reaffirmed her interest in science as a modus vivendi. Then Blackburn went on to what at the time was the Olympus of molecular biology, the Medical Research Council (MRC) laboratory in Cambridge, a place packed with past and future Nobel laureates that would become the gold standard for today's top scientific institutions.

The MRC laboratory was hosting a revolution in molecular biology, powered by discoveries about cellular mechanisms fundamental to life. Fred Sanger's DNA-sequencing work particularly attracted Blackburn, and from him she learned her pragmatic approach to science. As Brady points out, the heady ambience of the laboratory was marred by some male chauvinism (with Watson and Perutz receiving special mention). Blackburn discovered how things were in top scientific institutions: extreme dedication and long working hours, with no supporting hierarchies — what Brady calls a “rat lab”. Fellow scientists became her family substitutes and friends, and there she met her future husband, John Sedat.

Blackburn's DNA-sequencing skills were for her the key to discovery, and she took them to Joe Gall's lab in Yale after a short break to climb to Mount Everest's base camp with Sedat. In Gall's lab were some of the future principals of the telomere field — Ginger Zakian, Mary-Lou Pardue and, later, Tom Cech. It was there that Blackburn discovered in 1976 that Tetrahymena chromosomes end in a series of repeated runs of cytosine bases that varied in length.

Although this was the first molecular insight into the structure of chromosome ends, it was not seen as important by the community, which is surprising in view of its implications for chromosome replication and transmission of genetic information. Blackburn blames the perception of Tetrahymena as a “freak organism”. But it also fell outside what was then mainstream molecular biology. The story repeated itself when she, together with Carol Greider, discovered telomerase in 1985. By then it was clear that telomere replication was a fundamentally important process, but telomerase continued to receive scant attention until 1994–95, when it was shown to be aberrantly activated in most human cancers.

The biography succeeds in capturing Blackburn's vision, which has encouraged her to pursue unbeaten tracks to make discoveries that today hold therapeutic promise for both cancer and ageing.