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Quantitative Analysis of Aspergillus nidulans Growth Rate using Live Microscopy and Open-Source Software
Published on: July 24, 2021
Mapping Woronin body position in Aspergillus nidulans
Michelle Momany1, Elizabeth A Richardson, Carole Van Sickle
1Department of Botany, University of Georgia, Athens, Georgia 30602.
Mycologia
|December 16, 2010
Summary
Woronin bodies, essential organelles in Aspergillus nidulans, are concentrated in apical regions before septation. These organelles then move towards septa, indicating a role in cell division.
Area of Science:
- Cell Biology
- Mycology
- Fungal Development
Background:
- Woronin bodies are microbody-like organelles found in many filamentous fungi.
- Their precise localization and dynamic behavior during fungal growth, particularly in Aspergillus nidulans, remain incompletely understood.
- These organelles are known to be associated with septa, playing a role in sealing off damaged hyphal compartments.
Purpose of the Study:
- To determine the precise localization of Woronin bodies within Aspergillus nidulans germlings.
- To investigate the dynamic distribution of Woronin bodies during hyphal tip growth and septation.
- To confirm the identity of apical organelles as Woronin bodies using specific molecular markers.
Main Methods:
- Transmission electron microscopy (TEM) was employed to visualize Woronin bodies in plunge-frozen and freeze-substituted Aspergillus nidulans germlings.
- Immunolabeling using antibodies against the Neurospora crassa Woronin body matrix protein Hex1 was performed to confirm organelle identity.
- Quantitative analysis of Woronin body positions relative to the hyphal tip and septa was conducted.
Main Results:
- Woronin bodies were predominantly found near septa, as expected, but also in significant numbers within apical regions of A. nidulans germlings.
- Anti-Hex1 antibody labeling confirmed that these apical organelles are indeed authentic Woronin bodies.
- In pre-septation germlings, over 50% of Woronin bodies were located within 2.5 μm of the tip; this proportion decreased to 20% after septation, despite no overall change in organelle number.
Conclusions:
- Woronin bodies are actively localized to the apical regions of Aspergillus germ tubes during active growth.
- A significant redistribution of Woronin bodies from the apex to more basal regions occurs immediately before or during septation.
- These findings suggest a dynamic transport mechanism for Woronin bodies, potentially linking their apical accumulation to their function in septation.
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