My laboratory uses quantitative experiments and theory to study cell division, with an emphasis on investigating the spindle, the dynamic assembly that segregates chromosomes. We are trying to understand the self-organization of the spindle, the positioning of the spindle, and the mechanisms by which the spindles moves and accurately partitions chromosomes. We also study the differences in spindles between individuals and between species, and how failures in cell division can cause infertility. This has lead us to investigate possible connections between defects in mitochondria metabolism and defects in spindles, and pre-implantation embryo development more broadly.
In this talk, I will focus on our efforts investigating the movement and elongation of the spindle. I will argue that combining approaches from biophysics and quantitative genetics allows tests of broad classes of models of these processes. I will describe our experiments with a novel laser ablation system capable of cutting complex patterns with high spatial and temporal precision, and fluorescent nanodiamonds to track cytoplasmic fluid flow. We interpret our data using a combination of theory and simulations, performed in collaboration with Mike Shelley (NYU/Courant/Flatironan) and Ehssan Nazockdast (UNC). Our results argue that pulling forces from the cortex drive key aspects of spindle motions, including the initial centering, subsequent positioning, transverse oscillating behaviors, and elongation. This work points toward a quantitative, integrated framework for understanding spindle positioning.
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