Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
BP: Fachverband Biologische Physik
BP 25: Cell Mechanics II
BP 25.1: Vortrag
Donnerstag, 30. März 2023, 15:00–15:15, BAR Schö
Nuclear mechanics probed by optical tweezers-based active microrheology — •Bart Vos1, Till Müncker1, Ivan Avilov2, Peter Lenart2, and Timo Betz1 — 1Third Institute of Physics, University of Göttingen, Göttingen, Germany — 2Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
Mechanics play a crucial role in a wide range of cellular processes, from differentiation to division and metastatic invasion. Consequently, the mechanical properties of the cytoskeleton, providing shape, motility and mechanical stability to the cell, have been extensively studied. However, remarkably little is known about the mechanical environment within the nucleus of a cell, and fundamental questions remain unanswered, such as the role of nuclear actin or the sudden ``freezing" of the cell during cellular division that prevents diffusion or active mixing of the nucleus and the cytoplasm.
To address these questions, we perform optical tweezers-based microrheology in the cellular nucleus. Microrheology has proven to be a suitable tool for intracellular mechanical measurements, as it enables local, non-invasive measurements. However, although the cytoskeleton has been extensively studied this way, the cell nucleus has not been investigated, mainly due to difficulties with inserting appropriate probe particles. By using starfish oocytes that have larger dimensions than most other cell types, we are able to perform microinjection of micrometer-sized particles. We observe viscoelastic behavior of the nucleoplasm that is profoundly different from the cytoskeleton. In addition, we mechanically follow the oocyte during meiotic cell division.