Automated mitotic spindle tracking suggests a link between spindle dynamics, spindle orientation, and anaphase onset in epithelial cells

Matt Larson developed an automated spindle-tracking software – the “Spindlometer” – and applied it to address an ongoing question: How do spindles within an epithelium achieve their proper orientation, typically along the long axis of the cell and parallel with the epithelium, before making the decision to enter anaphase? By combining a reproducible imaging regime with his unbiased analysis pipline, Matt found that spindles within an epithelium undergo a stereotypical “dance” prior to anaphase onset. This dance is characterized by a low slow rotation from their initial orientation to their final orientation, followed by a series of rapid oscillations that repeatedly bring the spindle poles into close proximity to the cell cortex. We hypothesize that these cortical contacts may allow the spindle to sense its final orientation and either execute or delay anaphase onset as appropriate.