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Updated: Jun 19, 2026
Microscopy of Fission Yeast Sexual Lifecycle
Published on: March 9, 2016
Fission yeast Myo51 is a meiotic spindle pole body component with discrete roles during cell fusion and spore
Alex Doyle1, Rebeca Martín-García, Arthur T Coulton
1School of Biosciences, University of Kent, Canterbury, Kent, CT2 7NJ, UK.
Abstract:
Class V myosins are dimeric actin-associated motor proteins that deliver cellular cargoes to discrete cellular locations. Fission yeast possess two class V myosins, Myo51 and Myo52. Although Myo52 has been shown to have roles in vacuole distribution, cytokinesis and cell growth, Myo51 has no as yet discernible function in the vegetative life cycle. Here, we uncover distinct functions for this motor protein during mating and meiosis. Not only does Myo51 transiently localise to a foci at the site of cell fusion upon conjugation, but overexpression of the Myo51 globular tail also leads to disruption of cell fusion. Upon completion of meiotic prophase Myo51 localises to the outside of the spindle pole bodies (SPBs), where it remains until completion of meiosis II. Association of Myo51 with SPBs is not dependent upon actin or the septation initiation network (SIN); however, it is dependent on a stable microtubule cytoskeleton and the presence of the Cdc2-CyclinB complex. We observe a rapid and dynamic exchange of Myo51 at the SPB during meiosis I but not meiosis II. Finally, we show that Myo51 has an important role in regulating spore formation upon completion of meiosis.
Insights
Class V myosins, like Myo51 in fission yeast, are crucial motor proteins. This study reveals Myo51
Area of Science:
- Cell Biology
- Molecular Motors
- Cytoskeleton Dynamics
Background:
- Class V myosins are motor proteins that transport cellular cargo.
- Fission yeast has two class V myosins: Myo51 and Myo52.
- Myo52 is involved in cell division and growth, but Myo51's function was unknown.
Purpose of the Study:
- To investigate the functions of fission yeast's Myo51 during mating and meiosis.
- To understand the roles of Myo51 in cell fusion, spindle pole body association, and spore formation.
Main Methods:
- Microscopy to observe Myo51 localization during mating and meiosis.
- Genetic manipulation to study the effects of Myo51 overexpression.
- Analysis of Myo51's dependence on actin, SIN, microtubules, and Cdc2-CyclinB.
Main Results:
- Myo51 localizes to the cell fusion site during mating and its overexpression disrupts fusion.
- Myo51 associates with spindle pole bodies (SPBs) during meiosis II, dependent on microtubules and Cdc2-CyclinB.
- Myo51 exhibits dynamic exchange at SPBs during meiosis I and is vital for spore formation.
Conclusions:
- Myo51 plays distinct roles in fission yeast mating and meiosis, beyond vegetative functions.
- Myo51's localization and dynamics at SPBs are regulated by the cytoskeleton and cell cycle.
- Myo51 is essential for proper spore formation following meiosis.
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