Micro-organization and visco-elasticity of the interphase nucleus revealed by particle nanotracking

• DOI: 10.1242/jcs.01073
• Publication Date: 2004-04-16T17:43:00Z
• Authors: Yiider Tseng; Jerry S. H. Lee; Thomas P. Kole; Ingjye Jiang; Denis Wirtz
• Keywords: Interphase; Organelle; Protoplasm

The microstructure of the nucleus, one most studied but least understood cellular organelles, is subject much debate. Through use particle nanotracking, we detect and quantify micro-organization as well viscoelastic properties intranuclear region in single, live, interphase somatic cells. We find that stiffer than cytoplasm; it also more elastic viscous, which reveals displays an unexpectedly strong solid-like behavior. mean shear viscosity elasticity Swiss 3T3 fibroblasts are 520 Poise (P) 180 dyn/cm2, respectively. These measurements determine a lower bound propulsive forces (3-15 picoNewton) required for nuclear organelles such promyelocytic-leukemia bodies to undergo processive transport within nucleus by overcoming friction set viscosity. Dynamic analysis spontaneous movements nanospheres embedded presence putative transient microdomains size 290±50 nm, mostly absent cytoplasm. character revealed nanotracking may help preserve its structural coherence. studies highlight difference between low interstitial nucleoplasmic viscosity, controls proteins molecules, higher mesoscale affects diffusion directed re-organization chromosomes.