[Electron microscopy of spindle pole bodies in pathogenic fungi]

Area of Science:

• Mycology
• Cell Biology
• Microbiology

Background:

• Spindle pole bodies (SPBs) are crucial microtubule-organizing centers in fungi.
• Understanding SPB dynamics is key to comprehending cell division and fungal pathogenesis.
• Comparative studies of SPBs across different fungal species are limited.

Purpose of the Study:

• To investigate and compare the morphology and dynamics of SPBs in Exophiala dermatitidis and Cryptococcus neoformans.
• To elucidate the cell cycle-dependent localization and duplication of SPBs in these pathogenic yeasts.
• To highlight the differences in SPB behavior between these species and Saccharomyces cerevisiae.

Main Methods:

• Freeze-substitution and serial ultrathin sectioning electron microscopy were employed.
• High-resolution imaging was used to visualize SPB structures.
• Cell cycle staging was correlated with SPB morphology and localization.

Main Results:

• SPBs in Exophiala dermatitidis and Cryptococcus neoformans present with double forms.
• SPBs are associated with the nuclear envelope during the G1 phase.
• SPBs migrate to the nuclear membrane or periphery during M phase and appear to duplicate in early G1.

Conclusions:

• The SPB morphology and dynamics in Exophiala dermatitidis and Cryptococcus neoformans are distinct from those observed in Saccharomyces cerevisiae.
• These findings reveal unique cell cycle-dependent behaviors of SPBs in these medically relevant fungi.
• The study provides a foundation for further research into SPB function in fungal cell division and evolution.