Protocells: Milestones and Recent Advances

The origin of life is still one of humankind\u27s great mysteries. At the transition between nonliving and living matter, protocells, initially featureless aggregates of abiotic matter, gain the structure and functions necessary to fulfill the criteria of life. Research addressing protocells as a central element in this transition is diverse and increasingly interdisciplinary. The authors review current protocell concepts and research directions, address milestones, challenges and existing hypotheses in the context of conditions on the early Earth, and provide a concise overview of current protocell research methods

Rapid Growth and Fusion of Protocells in Surface-Adhered Membrane Networks

Elevated temperatures might have promoted the nucleation, growth, and replication of protocells on the early Earth. Recent reports have shown evidence that moderately high temperatures not only permit protocell assembly at the origin of life, but can have actively supported it. Here, the fast nucleation and growth of vesicular compartments from autonomously formed lipid networks on solid surfaces, induced by a moderate increase in temperature, are shown. Branches of the networks, initially consisting of self-assembled interconnected nanotubes, rapidly swell into microcompartments which can spontaneously encapsulate RNA fragments. The increase in temperature further causes fusion of adjacent network-connected compartments, resulting in the redistribution of the RNA. The experimental observations and the mathematical model indicate that the presence of nanotubular interconnections between protocells facilitates the fusion process

Styrene maleic acid copolymer induces pores in biomembranes

We investigated the interactions between styrene–maleic acid (SMA) copolymers and phospholipid bilayers, using confocal microscopy and surface acoustic wave resonance (SAR) sensing. For the first time we experimentally observed and followed pore formation by SMA copolymers in intact supported bilayers and unilamellar vesicles, showing that fluorescein, a water-soluble organic compound with a mean diameter of 6.9 Å, can traverse the membrane. Our findings are in agreement with recent theoretical predictions, which suggested that SMA copolymers may insert along the plane of the bilayer to form stable toroidal pores