Center for Computational & Integrative Biology, Massachusetts General Hospital
Department of Molecular Biology, Massachusetts General Hospital
Department of Chemistry and Chemical Biology, Harvard University
Department of Genetics, Harvard Medical School
Howard Hughes Medical Institute

Please visit the Exploring Life's Origins website for more movies and information on life's origins and the RNA World.

Please note that animations and illustrations on this website and on the Exploring Life's Origins website are licensed under a Creative Commons License, and may be freely downloaded for non-commercial uses with proper attribution. See bottom of page for more information.

Animations were made by Janet Iwasa, with narration by Tony Bell.

Non-enzymatic RNA replication

In the absence of RNA- or protein-based replication machinery, it is possible for RNA to replicate in a non-enzymatic, template-directed manner.   In this animation, the nascent RNA strand is formed from activated nucleotides by Watson-Crick base pairing.

download movie (Quicktime, 28 Mb)

Fatty Acid Synthesis & Dispersal

This animation depicts  a hypothetical scenario where fatty acids are formed along the inner face of a geyser.  Using carbon monoxide as a carbon source, minerals present along the geyser walls catalyze the formation of hydrocarbon chains of various lengths which are eventually released as fatty acids into the central geyser cavity.

The eruption of the geyser disperses the geyser contents, including low concentrations of fatty acids.  Air currents and heat cause smaller water droplets to evaporate, and the resulting dry fatty acid particulates may travel long distances by means of wind.

download movie (Quicktime, 191 Mb)

Vesicle Growth via Micelle Shell

Addition of micelles to a solution of preformed vesicles has been shown to cause rapid vesicle growth.  Micelles are thought to first form a coat surrounding vesicles.  Fatty acids are then transferred from the micelles to the outer leaflet of the vesicle.  Flip-flopping allows fatty acids to equilibrate between the inner and outer leaflets.

download movie (Quicktime, 53 Mb)

Fatty Acid Dynamics

While vesicles as a whole are extremely stable, individual fatty acids that comprise the vesicle are in constant flux.  Fatty acids may enter and exit the vesicle and flip-flop between the inner and outer leaflets when they are in a protonated form.  In this animation, flip-flopping fatty acids are shown briefly in white.

download movie (Quicktime, 45Mb)

Nucleotide Entry into Vesicle

Individual nucleotides are able to passively translocate across the vesicle membrane, mediated by electrostatic and hydrophobic interactions between the fatty acids and nucleotides.

download movie (Quicktime, 58 Mb)

de novo Vesicle Nucleation

This animation illustrates how fatty acid micelles may form a vesicle de novo.  Fatty acid micelles, when unprotonated (shown in dark gray/dark red) do not easily fuse together despite collisions.  Upon the addition of acid (glowing spheres represent H+), fatty acids become protonated, and the structures they form more fluid and dynamic.  These micelles join together to form a sheet-like membrane.  Random fluctuations in the membrane cause the formation of a cup-like shape followed by edge annealing.

download movie (Quicktime, 45 Mb)

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