Dr. Libchaber studies mathematical patterns in biology at both the organism and the cellular and molecular levels. Using the model of a fish swimming, Dr. Libchaber’s research has examined the effects of moving boundary conditions, the conditions to which a set of differential equations must adhere to, on fluid flow. A moving fish involves a complicated interaction of a dynamic object with the surrounding fluid, with forces by both elements acting on one another. In the lab, Dr. Libchaber, in collaboration with researchers at New York University’s Courant Institute of Mathematical Sciences, studied a system of flexible filaments in a flowing soap film, which has analogy to a model of a fish moving in water.

Recently, Dr. Libchaber’s lab has undertaken a whole new series of experiments at the single molecule level, the results of which may hold clues to the origins of life. Dr. Libchaber is working to define the minimal conditions needed to produce an artificial cell. Within a phospholipid vesicle, which mimics a cell membrane, Dr. Libchaber places DNA containing the necessary genes and their regulatory sequences. This cell, which is in contact with a feeding solution through its semi-permeable membrane, is then the environment for testing different gene networks and elementary logic circuits for their ability to reproduce essential events in a cell’s life, such as producing proteins and transporting them to the cell’s surface. The ultimate aim is to produce an artificial cell that self-reproduces following a genetic program.

Another important concept at the origin of life is the development of a genetic code that relates the 20 amino-acid world to the 4 nucleotide one. Dr. Libchaber is trying to show that a RNA molecule of a stem-loop structure, acting as a ribozyme, can load an amino-acid to its 3' end. This amino acid should correspond to the anticodon in the loop, and all this is done without enzymes.

Past research in Dr. Libchaber’s lab has elucidated the effects of temperature on DNA. In a detailed study on the effects of thermophoresis on DNA in solution, they found that when far infrared lights are focused on the center of a chamber, DNA within the chamber moves from a hot region to a cold one. As the heating is increased, however, convection sets in and causes the opposite: the DNA collects and accumulates in the bottom center of the chamber. Because this phenomenon could be used to sustain very high concentrations of DNA or proteins, it sheds light on how critical concentrations of DNA may have been reached amid early primordial soup chain reactions, and therefore played an important role in early life forms. The Libchaber lab has also shown that PCR is a natural phenomenon of convection, melting of DS DNA in the hot region and SS DNA elongation in the cold region of a convective cell.

CAREER

Dr. Libchaber, born in Paris, received his undergraduate degree in mathematics from the University of Paris in 1956. In 1959, he received his M.S. in physics from the University of Illinois and in 1965 earned his Ph.D. in physics from the École Normale Supérieure at the University of Paris. Dr. Libchaber was a member of the technical staff at Bell Telephone Laboratory from 1965 to 1966, and was invited back for each of the next five consecutive summers, from 1967 to 1972. In 1974, he became research director at the Centre Nationale de la Recherche Scientifique, in Paris. He moved to the University of Chicago’s department of physics and James Franck and Enrico Fermi Institutes as a professor in 1983. From 1991 to 1994, he was a professor in the department of physics at Princeton University before coming to Rockefeller University in 1994.

In 1999, Dr. Libchaber was awarded the Prix des Trois Physiciens from the Fondation de France. He received both the Wolf Foundation Prize in Physics and a MacArthur Foundation Fellowship in 1986. He is a member of the French Academy of Sciences and the American Academy of Arts and Sciences.