Dissecting the mechanical heterogeneity of intracellular organelles and their contribution to development and disease

The ability to sense and respond to mechanical information is pivotal for tissue organization, organismal development and neuronal function. It is well understood how the the plasma membrane and the actin cortex endow the cell with the ability to measure forces, measuring how the nucleus, mitochondria and the ER respond to forces is still a formidable challenge. In this talk, I will focus on our efforts to develop a versatile optical tweezer technique to characterize the intracellular rheology of various biosystems. This technique uses a single, time-shared laser beam to measure both, stress and strain, from which we obtain the viscoelastic response function of the intracellular compartment in real time. To demonstrate this TimSOM (Time-Shared Optical tweezer Microrheology) technique, I will showcase results how the viscoelasticity of the cytoplasm, nuclear interface, and nucleoplasm of zebrafish cells change in various conditions. Lastly, I will mention our efforts to understand how the mechanical properties of the cytoplasm and the nucleus change over the lifespan of the genetic model Caenorhabditis elegans and in mutations that are know to cause premature aging in humans.