Single cell physiology

The possibility to control at specific times and specific places the activity of biomolecules (enzymes, transcription factors, RNA, hormones, etc.) is opening up new opportunities in the study of physiological processes at the single cell level in a live organism. Most existing gene expression systems allow for tissue specific induction upon feeding the organism with exogenous inducers (e.g. tetracycline). Local genetic control has earlier been achieved by micro-injection of the relevant inducer/repressor molecule but this is an invasive and possibly traumatic technique. Here we will present the requirements for a non-invasive optical control of the activity of biomolecules and review the recent advances in this new field of research. Pierre Neveu Kavli Institute for Theoretical Physics, University of California at Santa Barbara, Santa Barbara, USA, e-mail: [email protected] Deepak Sinha Laboratoire de Physique Statistique UMR 8550, Ecole Normale Supérieure, Paris, France e-mail: [email protected] Petronella Kettunen Department of Physiological Science, University of California at Los Angeles, Los Angeles, USA e-mail: [email protected] Sophie Vriz Inserm U770,Hémostase et Dynamique Cellulaire Vasculaire, Le Kremlin-Bicêtre, France e-mail: [email protected] Ludovic Jullien Département de Chimie UMR 8640, Ecole Normale Supérieure, Paris, France e-mail: [email protected] David Bensimon Laboratoire de Physique Statistique UMR 8550, Ecole Normale Supérieure, Paris, France Department of Chemistry and Biochemistry, University of California at Los Angeles, Los Angeles, USA e-mail: [email protected]