Mendel Medal 2013 – Dr Stanislas Leibler

We are delighted to announce that Professor Stanislas Leibler of the Institute of Advanced Study Princeton and The Rockefeller University New York, has been awarded the 2013 Mendel Medal, and will deliver a lecture at the Genetics Society Autumn meeting on Nov 7-8, 2013 at the Royal Society of London. The field of genetics has greatly benefited from scientists who were originally trained in physics, such as Gregor Mendel and Francis Crick.

Their physics background led them to formulate biological questions from a fresh perspective, and gave them a deep appreciation of how mathematical concepts could be applied to experimental problems. This approach also underlies the work of Stanislas Leibler who obtained a PhD in theoretical physics in 1981 and a second PhD in physics in 1984 at the University of Paris.

Professor Leibler started to apply his mind to biological problems in 1992 when he moved to Princeton University. He asked himself how multiple gene products could interact to produce the robust phenotypic outcomes observed in nature. Using a combination of theoretical and experimental approaches, he showed that network architecture played a critical role in robustness, using the processes of bacterial chemotaxis to illustrate his point. He went on to show how an understanding of genetic networks could be used to engineer particular phenotypes such as logical circuits or oscillators. These findings both clarified and validated our notions of gene interaction, and were landmark studies in the growing fields of Systems and Synthetic Biology.

After the turn of the century Professor Leibler’s work started to take a more statistical and evolutionary slant as he became intrigued by the problem of bacterial persistence. This problem refers to the ability of a fraction of bacteriain a genetically homogeneous population to survive a stress such
as exposure to antibiotics. Unlike resistant mutants, cells regrown from such persistent bacteria remain sensitive to the antibiotic. Leibler showed through quantitative measurements that bacterial persistence could be accounted for by a simple mathematical description in which cells have defined probabilities of switching between a fast growing form and a less susceptible slow growing form. This switching behaviour may confer a selective advantage in fluctuating environments, an example of bethedging. Leibler went on to address further evolutionary problems, such as the basis of cooperation between individuals, using an elegant combination of microbial gene engineering and mathematical analysis. In recognition of his seminal contributions to our understanding of gene action, Professor Leibler joins a list of illustrious Genetics Society Mendel Lecturers going back to 1958.