School of Physics Soft Condensed Matter & Biophysics Seminar: Prof. Albert Libchaber, Rockefeller University

Self –reproduction, the production of an offspring identical with the parent is a fundamental conceptual problem. We first present the historical evolution of the concept, insisting on Von Neumann machine logic “What are structures which produce further identical structures”. We then describe the state and development of an artificial cell project, and its feasibility to self‐reproduce. We will insist on the importance of the cytoskeleton. We will show that by adding fatty acids to the outside world, the artificial cell can destabilize, producing many vesicles. This could have been an archaic self -reproduction process, as shown by Errington for spherical bacteria. We finally show how delicate is self-reproduction by applying a high hydrostatic pressure to stressed E.coli bacteria. DNA and proteins are all produced and they self-reproduce but the bacteria cannot divide, it elongates. The process is reversible; bringing back the bacteria to normal pressure the elongated cell starts to divide and comes back to its normal size.