Live-cell imaging of mitochondrial motility and interactions in Drosophila neurons and yeast

Enrichment of aging yeast cells and budding polarity assay in Saccharomyces cerevisiae

Replicative lifespan, a measure of the number of times that a yeast cell can divide before senescence, is one model for aging. Here, we provide a protocol for enrichment of yeast as a function of replicative age using a miniature chemostat aging device (mCAD). This protocol allows for isolation of quantities of cells that are sufficient for biochemical or genomic analysis. We also describe an approach to assess bud site selection, a marker for cell polarity, during the aging process.

For complete details on the use and execution of this protocol, please refer to Yang et al. (2022).

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Step-by-step protocol to assemble a mini-chemostat aging device (mCAD)

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Protocol to use the mCAD to isolate yeast as a function of replicative age

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Characterization of basic aging phenotypes of cells isolated using the mCAD

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Protocol to analyze budding polarity in young and old yeast cells

Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics.

Imaging the Actin Cytoskeleton in Live Budding Yeast Cells

Although budding yeast, Saccharomyces cerevisiae, is widely used as a model organism in biological research, studying cell biology in yeast was hindered due to its small size, rounded morphology, and cell wall. However, with improved techniques, researchers can acquire high-resolution images and carry out rapid multidimensional analysis of a yeast cell. As a result, imaging in yeast has emerged as an important tool to study cytoskeletal organization, function, and dynamics. This chapter describes techniques and approaches for visualizing the actin cytoskeleton in live yeast cells.

Live-Cell Imaging of Mitochondrial Redox State in Yeast Cells

The redox state of mitochondria is one indicator of the functional state of the organelles. Mitochondria are also the primary endogenous source of reactive oxygen species (ROS). Therefore, the redox state of the organelles also reflects their function in ROS production. Here, we provide step-by-step protocols for live-cell imaging and quantification of mitochondrial redox state using the genetically encoded fluorescent biosensor, mitochondria-targeted redox sensing GFP (mito-roGFP), and mitochondrial ROS using the membrane-permeant small molecule dihydroethidium (DHE) in budding yeast cells.

For complete details on the use and execution of this protocol, please refer to Liao et al. (2020c).

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Protocols for analysis of mitochondrial redox state and ROS in S. cerevisiae

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Analysis is performed in living cells at the resolution of individual organelles

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Methods for analysis using commercial and open-source software are provided

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These protocols can be adapted for use in other cell types