Rhinosporidium seeberi Nuclear Cycle Activities Using Confocal Microscopy
Darly Delfino1, Leonel Mendoza, Raquel Vilela1
1Faculty of Pharmacy, Federal University of Minas Gerais, Pres. Antônio Carlos, 6627-Pampulha, Belo Horizonte-MG, 31270-901, Brazil.
The Journal of Parasitology
|October 14, 2015
Summary
Rhinosporidium seeberi undergoes synchronized nuclear division without cell division, forming thousands of nuclei. This process occurs before mature sporangia develop, with cell division happening only once.
Area of Science:
- Mycology
- Parasitology
- Cell Biology
Background:
- Rhinosporidium seeberi is an uncultivated Ichthyosporean pathogen infecting humans and animals.
- Previous research suggested R. seeberi exhibits synchronized nuclear division without cytokinesis.
Purpose of the Study:
- To investigate the nuclear division cycles of Rhinosporidium seeberi using confocal microscopy.
- To elucidate the process of nuclear division and cytokinesis in R. seeberi sporangia.
Main Methods:
- Confocal microscopy was employed on formalin-fixed tissues.
- DAPI and phalloidin staining were used to visualize nuclei and cellular structures.
- Microscopic analysis focused on juvenile, intermediary, and mature sporangia.
Main Results:
- Synchronous nuclear division without cytokinesis was observed in juvenile and intermediary R. seeberi sporangia.
- Intermediary sporangia contained numerous nuclei (3-4 μm) in various mitotic stages and a phalloidin-avid inner layer.
- Mature sporangia contained cell-walled endospores (5-12 μm) with nuclei (2-4 μm), lacking the phalloidin-avid inner layer.
Conclusions:
- Rhinosporidium seeberi life cycle involves synchronous nuclear divisions without cytokinesis, leading to thousands of nuclei.
- Cytokinesis is a singular event in late-stage intermediary sporangia, preceding mature sporangia formation.
- A "germinative zone" with numerous nuclei develops in mature sporangia.
