Communication and interaction among surfaceadhered membranous protocells

Abstract

Tunneling nanotubes are ubiquitous in long-distance communication in all domains of life. Similarly, spontaneously formed lipid nanotubes could have allowed the transport of diffusive cargo among primitive cells without the need to cross membrane boundaries. This thesis provides the experimental evidence for the origin of life hypothesis on protocell populations. Protocells may have emerged under prebiotic conditions and formed colony-like protocell populations, in the transition to the first living cell populations. These processes can be accelerated by temperature increase in local environment. Within protocell population, each individual protocell is capable of exchanging contents with its neighbors, mediated by the interconnected membrane nanotubes. The interactions between protocells and their adhering solid surfaces are the focus of this thesis. Specifically, the intrinsic energies of solid surfaces, such as minerals and rocks on early Earth, can be harvested by organic molecules adhering to them. By adhering to engineered silica surfaces, lipid assemblies have been found to undergo topological transformations, including tubulation, vesiculation, and fusion. These observations have therefore led to the suggestion that natural surfaces may have initiated the development of protocell populations with communicating properties.