Understanding the mechanisms of the cellular aging processes is crucial for attempting to extend organismal lifespan and for studying age-related degenerative diseases. Yeast cells divide through budding, providing a classical biological model for studying cellular aging. With their powerful genetics, relatively short cell cycle, and well-established signaling pathways also found in animals, yeast cells offer valuable insights into the aging process.
Mark Alber
University of California, Riverside
Recent experiments suggested the existence of two aging modes in yeast characterized by nucleolar and mitochondrial declines, respectively. By analyzing experimental data, this study shows that cells evolving into those two aging modes behave differently when they are young. While buds grow linearly in both modes, cells that consistently generate spherical buds throughout their lifespan demonstrate greater efficacy in controlling bud size and growth rate at young ages.
A three-dimensional multiscale chemical-mechanical model was developed and used to suggest and test hypothesized impacts of aging on bud morphogenesis [1]. Experimentally calibrated model simulations showed that during the early stage of budding, tubular bud shape in one aging mode could be generated by locally inserting new materials at the bud tip, a process guided by the polarized Cdc42 signal. Furthermore, the aspect ratio of the tubular bud could be stabilized during the late stage as was also observed in experiments. The model simulation results suggest that the localization of new cell surface material insertion, regulated by chemical signal polarization, could be weakened due to cellular aging in yeast and other cell types, leading to the change and stabilization of the bud aspect ratio.
Professor Mark Alber earned his Ph.D. in mathematics at the University of Pennsylvania. He held several positions at the University of Notre Dame including most recently Vincent J. Duncan Family Chair in Applied Mathematics. Dr. Alber retired from the University of Notre Dame in 2016 and became Professor Emeritus. He is currently Distinguished Professor in the Department of Mathematics and Director of the Center for Quantitative Modeling in Biology, University of California, Riverside.
Dr. Alber was elected in 2011 Fellow of the American Association for the Advancement of Science (AAAS) and received 2024 US Fulbright Scholar Award (The Netherlands). He is currently a section editor in systems biology of PLoS Computational Biology and member of the editorial board of Bulletin of Mathematical Biology.