Cytoskeletal forces are delivered on the nucleus via nuclear envelope bridging complexes called LINC complexes (linker of nucleoskeleton and cytoskeleton), which physically couple the cytoskeleton to the nuclear interior and the peripheral chromatin (Fig 1A). These complexes can mechanically transmit cytoskeletal forces to chromatin and impinge on chromatin biology, for example during homologous chromosome pairing in meiosis. In addition, peripheral chromatin is important for providing a physical network to buffer cytoskeletal forces applied to the nuclear envelope during nuclear migration.
The role that chromatin and its connections to the LINC complex and the nuclear envelope play in maintaining nuclear integrity and buffering these forces is not well characterized. However, structural integrity of the nucleus is lost when attachments of chromatin to the NE are removed (Fig. 1B) which suggests that chromatin tethered to the periphery and linked to the cytoskeleton acts as a washer in a nut and bolt system to help buffer cytoskeletal forces by distributing them over a greater area of the INM (Fig.1D).
In vivo Fluorescence Assay
To determine how detaching peripheral chromatin from the nuclear envelope affects nuclear mechanics, fluorescently labelled nuclei will be imaged in vivo and analyzed for fluctuation number, size and persistence time.
Optical Tweezers Assay
To understand the mechanical properties of nuclei, this experimental design was developed to assay nuclei isolated from the genetic model organism, Schizosaccharomyces pombe.
