Our friend Claudia Melcarne, from UPSIM lab (EFPL, SV ISREC department), brought us these samples of Schizosaccharomyces pombe for a free testing with the 3D Cell Explorer, and it was a great idea ! She was interested in looking at the cell division in 3D, marker-free & real time, to observe in a new way the effect of Cdc16 mutation on the regulation of contractile ring formation.
Check out these amazing videos we put together thanks to the 3D Cell Explorer!
Schizosaccharomyces pombe, also known as “fission yeast”, is a species of yeast used in traditional brewing and as a model organism in molecular and cell biology. Fission yeast is a powerful tool in cell cycle research due to their forms, a simple cylindrically shape, and the fact that they divide by medial fission. On top of that, the division is really fast (from 2 to 4 hours) and can be easily seen under a microscope.
The cells, maintain their shape by growing exclusively through the cell tips and divide by medial fission to produce two daughter cells of equal sizes, as shown in the following scheme.
The Cell Cycle. Principles of Control – David O Morgan
Cytokinesis is an important mechanism that needs to be perfectly performed by the cell otherwise its survival is compromised. One of the crucial part of this phenomenon is dependent on the contractile ring formation which is highly conserved in both fission yeast and human cytokinesis. A mutation in cytokinesis can lead to multiple malfunction (i.e. cell death and cancerous cells formation).
Beginning from a simple model such as S. pombe, allows to build up a higher-order model that can be applied to humans.
Fission yeast (Schizosaccharomyces pombe) were grown in Yeast Extract medium in 35mm glass bottom culture dish (µ-Dish 35 mm, high Glass Bottom – Ibidi, 500 thousands of cells).
The WT strain life cycle monitoring was conducted with a standard top-stage incubator set to 26°C and 5% CO2 for 8 hours, capturing images every 2 minutes and 30 seconds. Then, the Cdc16 heat sensitive mutant strain was monitored but at 36°C and 5% CO2. Cdc16 protein has a regulatory function in inhibiting septation during interphase. In the Heat sensitive mutant strain this protein cannot fold properly at 36°C and therefore the contractile ring formation is happening at the wrong time (accumulation of septa during interphase).
Nanolive digital staining allows you to discriminate the different yeast biological components based on their specific Refractive Index (RI) range: Membrane in Purple, Citosol in Light Blue, Nuclei and Organelles in Yellow, Contractile Ring in Red.