A 3D analysis revealed complexe mitochondria morphologies in porcine cumulus cells




Lounas, Amel
Lebrun, Ariane
Laflamme, Isabelle
Vernoux, Nathalie
Savage, Julie
Tremblay, Marie-Ève
Germain, Marc
Richard, François J.

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Scientific Reports


In the ovarian follicle, a bilateral cell-to-cell communication exists between the female germ cell and the cumulus cells which surround the oocyte. This communication allows the transit of small size molecules known to impact oocyte developmental competence. Pyruvate derivatives produced by mitochondria, are one of these transferred molecules. Interestingly, mitochondria may adopt a variety of morphologies to regulate their functions. In this study, we described mitochondrial morphologies in porcine cumulus cells. Active mitochondria were stained with TMRM (Tetramethylrhodamine, Methyl Ester, Perchlorate) and observed with 2D confocal microscopy showing mitochondria of different morphologies such as short, intermediate, long, and very long. The number of mitochondria of each phenotype was quantified in cells and the results showed that most cells contained elongated mitochondria. Scanning electron microscopy (SEM) analysis confirmed at nanoscale resolution the different mitochondrial morphologies including round, short, intermediate, and long. Interestingly, 3D visualisation by focused ion-beam scanning electron microscopy (FIB-SEM) revealed different complex mitochondrial morphologies including connected clusters of different sizes, branched mitochondria, as well as individual mitochondria. Since mitochondrial dynamics is a key regulator of function, the description of the mitochondrial network organisation will allow to further study mitochondrial dynamics in cumulus cells in response to various conditions such as in vitro maturation.


The authors thank Alexandre Bastien for its technical support and advice, Annie Rioux for collecting ovaries, Martin Pelletier for giving Rotenone, the Olymel meat-processing company for providing gilt ovaries and the Object Research Systems for giving Dragonfly software license.


Cell biology, Physiology, Reproductive biology


Lounas, A., Lebrun, A., Laflamme, I., Vernoux, N., Savage, J., Tremblay, M-È., Germain, M., & Richard, F. J. (2022). A 3D analysis revealed complexe mitochondria morphologies in porcine cumulus cells. Scientific Reports, 12, 15403, https://doi.org/10.1038/s41598-022-19723-2