Genome Evolution from Random Ligation of RNAs of Autocatalytic Sets

Area of Science:

• Origin of Life Studies
• Molecular Evolution
• Biochemistry

Background:

• The evolutionary path from simple prebiotic chemistry to complex cellular life, particularly the origin of the genome, remains a significant scientific challenge.
• Understanding the transition from non-living matter to self-replicating entities is crucial for deciphering life's fundamental processes.

Purpose of the Study:

• To propose a novel hypothesis for the evolutionary origin of the genome, termed the protogenome.
• To elucidate the potential structure, function, and evolutionary trajectory of this hypothesized early genetic material.

Main Methods:

• Hypothetical modeling of early RNA-based life within protocells.
• Postulation of ribozyme-catalyzed ligation and polymerase-mediated amplification as key evolutionary mechanisms.
• Conceptual framework for the development of protometabolism, genetic code, and transition to DNA.

Main Results:

• The protogenome is hypothesized as a multi-ribozyme RNA, formed via ligation and amplified by a polymerase within liposomes.
• This protogenome linked information to seed protometabolism, enabling autocatalytic sets and quasispecies dynamics.
• Evolutionary progression led to templating of metabolism, development of a genetic code, and eventual transition to a DNA genome.

Conclusions:

• The protogenome hypothesis offers a plausible pathway for the origin of the genome from simpler RNA components.
• This model integrates key concepts like protocells, ribozymes, and autocatalysis to explain early genetic system evolution.
• Experimental validation of ribozyme ligase and polymerase activities is suggested to support this evolutionary scenario.