Self-Replication Without Hydrogen-Bonds: An Exobiotic Design

Area of Science:

• Astrobiology
• Synthetic Chemistry
• Origin of Life Studies

Background:

• Life on Earth relies on DNA for replication and information transfer.
• The search for extraterrestrial life (exobiology) faces challenges in identifying non-DNA-based biosignatures.
• Organic compounds found on Mars and in TMC-1 suggest potential building blocks for alternative life.

Purpose of the Study:

• To design and synthesize a novel, DNA-free self-replicating system.
• To explore alternative templating mechanisms beyond DNA's hydrogen bonding.
• To investigate systems with structural similarities to extraterrestrial organic compounds.

Main Methods:

• Designed a self-replicating system utilizing sulfur-nitrogen interactions for templating.
• Synthesized benzothiadiazole units for sequence-specific replication.
• Studied both reversible and irreversible versions of the system.
• Conducted experiments in d-chloroform solvent to observe self-replication.

Main Results:

• Experimental evidence of self-replication was observed in the synthesized system.
• The system employs sulfur-nitrogen interactions, distinct from DNA's hydrogen bonding.
• Two versions of the system (reversible and irreversible) were successfully synthesized and tested.

Conclusions:

• A novel, DNA-free self-replicating system has been demonstrated.
• This system offers a potential model for unconventional exobiological systems.
• The findings support the development of biosignatures based on extraterrestrial organic chemistry.