BRC-BIO: Building a Cell - Coupling Amphiphile Prebiotic Chemistry to Protocell Heredity

About This Grant

A fundamental trait of cells is the fact they are encapsulated by a membrane, whose assembly was most likely one of the early steps during life’s emergence on the early Earth. Membrane assembly is a spontaneous event driven by the simple fact that oil and water do not mix. This project seeks to understand how membrane encapsulated vesicles (protocells) might have formed and reproduced in the absence of any genetic information. The project investigates how molecules that are amphiphilic (simultaneously polar and non-polar) assemble into vesicle compartments, and how these compartments might drive the formation of additional membrane building blocks. This project tackles whether information can be carried over across generations of vesicles, with offspring adapting to their environment over time. If true, this will demonstrate the feasibility of a form of Darwinian evolution on a system that does not (yet) contain genes. A Course-Based Undergraduate Research Experience Astrobiology course where students design a space exploration mission will be expanded. The course is designed to develop a teamwork ethos, critical thinking, data analysis, and public presentation skills. The novelty of the type of laboratory work involved would provide students the opportunity to develop a unique skill set in microfluidics. This project has three main scientific goals: (i) use catalytic minerals to promote the synthesis and polymerization of organosulfur species to yield amphiphilic molecules. (ii) Probe the capability of such amphiphiles to self-assemble into vesicle compartments and develop a robust methodology for studying their individual and population-wide composition. And (iii) assess if such vesicles display generational heredity – allowing for a primitive form of evolution by natural selection. Selection pressures, such as changes in temperature and pH, will be applied to determine if the naturally-selected composition of older generations biases that of future ones. Custom-made microfluidic setups will be incorporated to enable the control and manipulation of fluids constrained to the microliter scale, where surface forces prevail over volumetric ones, and allow for the simulation of the out-of-equilibrium conditions naturally found in energy-rich geochemical settings. This interdisciplinary project is at the crossroads between chemical biology, biophysics, and evolutionary biology and is poised to tackle the critical challenge of how the first cells were built. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.