Poster abstracts
Poster number 35 submitted by Hari Krishnan Balasubramanian
Active mitochondrial fission during fungal biofilm formation
Hari Krishnan Balasubramanian (MCDB)
Abstract:
Fungal biofilms, formed by fungal cells that attach to a surface and grow, have unique characteristics including the presence of an extracellular matrix and resistance to anti-fungal drugs as well as the host immune system. As biofilms form they self-generate internal hypoxic microenvironments similar to that of tumors. Fungal biofilms therefore provide a unique opportunity to understand the mechanism of cell growth and survival in self-generated hypoxic/nutrient deprived conditions. Current understanding of the cell biology of biofilm forming cells is limited. In recent unpublished findings, we have seen mitochondria undergo fragmentation during fungal biofilm formation. A recent study demonstrated that upon deletion of DnmA and/or FisA, two core components of the mitochondrial fission machinery, mitochondria fail to undergo fragmentation after treatment with hydrogen peroxide in Aspergillus nidulans (Garrido-Bazán et al., 2020). To test if the mitochondrial fission machinery is required for the biofilm-formation induced fragmentation of mitochondria, we developed strains deleted for individual components of the mitochondrial fission machinery, namely DnmA, FisA and Mdv1. These strains show a loss of mitochondrial fragmentation during fungal biofilm formation, demonstrating a requirement of mitochondrial fission machinery for biofilm-formation induced mitochondrial fragmentation. Our findings show that the cells are able to form a biofilm even when they lose of the ability to undergo mitochondrial fragmentation, and that the biofilm formation induced dispersal of microtubules is not dependent on the ability to undergo mitochondrial fragmentation. Our future work will focus on determining how autophagy is affected in the absence of mitochondrial fragmentation. (Shukla et al., 2017 and Lingo et al., 2021).
References:
Garrido-Bazán, V., Pardo, J. P., & Aguirre, J. (2020). DnmA and FISA mediate mitochondria and peroxisome fission, and regulate mitochondrial function, ROS production and development in aspergillus nidulans. Frontiers in Microbiology, 11.
Lingo, D. E., Shukla, N., Osmani, A. H., & Osmani, S. A. (2021). aspergillus nidulans biofilm formation modifies cellular architecture and enables light-activated autophagy. Molecular Biology of the Cell, 32(12), 1181–1192.
Shukla, N., Osmani, A. H., & Osmani, S. A. (2017). Microtubules are reversibly depolymerized in response to changing gaseous microenvironments within aspergillus nidulans biofilms. Molecular Biology of the Cell, 28(5), 634–644.
Keywords: Biofilm, hypoxic microenvironment, autophagy