Dr. Mary Elting and Dr. Sharonda LeBlanc recently came out with a new paper titled, “Mechanical Coupling With the Nuclear Envelope Shapes the Schizosaccharomyces pombe Mitotic Spindle.” It was published May 10, 2025. It was also written by current NCSU grad students Taylor Mahoney and Christian Medina. The other authors are previous NCSU students.
Abstract:
“The fission yeast Schizosaccharomyces pombe divides via closed mitosis, meaning that spindle elongation and chromosome segregation transpire entirely within the closed nuclear envelope. Both the spindle and nuclear envelope must undergo shape changes and exert varying forces on each other during this process. Previous work has demonstrated that nuclear
envelope expansion (Yam, He, Zhang, Chiam, & Oliferenko, 2011; Mori & Oliferenko, 2020) and spindle pole body (SPB) embedding in the nuclear envelope are required for normal S. pombe mitosis, and mechanical modeling has described potential contributions of t
he spindle to nuclear morphology (Fang et al., 2020; Zhu et al., 2016). However, it is not yet fully clear how and to what extent the nuclear envelope and mitotic spindle each directly shape each other during closed mitosis. Here, we investigate this relationship by observing the behaviors of spindles and nuclei in live mitotic fission yeast following laser ablation. First, we characterize these dynamics in mitotic S. pombe nuclei with increased envelope tension, finding that n
uclear envelope tension can both bend the spindle and slow elongation. Next, we directly probe the mechanical connection between spindles and nuclear envelopes by ablating each structure. We demonstrate that envelope tension can be relieved by severing spindles and that spindle compression can be relieved by rupturing the envelope. We interpret our experimental data via two quantitative models that demonstrate that fission yeast spindles and nuclear envelopes are a mechanical pair that can each shape the other’s morphology.”