Self‐replication plays a central role in the origin of life and in strategies to synthesize life de novo. Studies on self‐replication have focused mostly on isolated systems; the dynamics of systems containing multiple replicators have received only little attention, although most evolutionary scenarios involve the interplay between different replicators.
Sijbren Otto and colleagues, University of Groningen, The Netherlands, have explored the development of parasitic behavior in a system containing self‐replicators derived from two subtly different building blocks 1 and 2. They observed how a set of 6‐ring replicators emerged, aided by a pre‐existing 8‐ring replicator, only to consume the 8‐rings to which the new replicator owed its existence.
Thiol-functionalized peptide building blocks 1 and 2 (pictured below) were synthesized. The two compounds have different, structurally imposed abilities to nucleate. An extra methylene group in the structure of 2 ensures that the molecule is a poor self-replicator that requires help from other replicators to grow efficiently.
A hexameric system, 1n26-n, grew from a stirred mixture of 1 and 2 within days, and with the help of parasitized building blocks sourced from an 8-ring replicator 18. The octamer was consumed, even as it cross-catalyzed the formation of the hexamer.
Examples of parasitism exist in natural systems where enzymes mediate the replication of nucleic acids, but according to the team their study is the first to detect parasitism in a system of synthesized self-replicators. These observations illustrate the rich dynamics of multireplicator systems. Understanding these dynamics is essential for directing the evolution of multireplicator systems towards the de novo synthesis of life.
- Parasitic Behavior of Self-Replicating Molecules,
Meniz Altay, Yigit Altay, Sijbren Otto,
Angew. Chem. Int. Ed. 2018.