Origins of Life Could Have Started With DNA-like molecules

A group of researchers from Nagoya University scientists in Japan have demonstrated how DNA like molecules contributed to the origin of life. These findings were published in the Nature Communications journal. The researchers not only found the origin of life but also implications for the development of artificial life and biotechnology applications.

Keiji Murayama, biomolecular engineer of Nagoya University said that the RNA is widely thought to be a stage in the origin of life. Before this stage, the pre-RNA world may have been based on molecules called Xeno nucleic acids. The Xeno nucleic acid replication didn’t require enzymes. Researchers can synthesize a Xeno nucleic acid without enzymes, strongly supporting the hypothesis that an XNA world might have existed before the RNA world.

Xeno nucleic acids are composed of chains of linked nucleotides which is similar to DNA and RNA but with a different sugar backbone. The Xeno nucleic acids can carry a genetic code very stable because the human body can’t break them down. Researchers have reported that Xeno Nucleic acids contain specific sequences that can act as enzymes and bind to proteins. This makes XNAs are in the field of synthetic genetics, with potential biotechnology and molecular medicine applications.

The group of researchers tried to find out whether this condition was present on early Earth could have led to XNA chain formation. They synthesized fragments of acyclic L-threonine nucleic acid, a molecule that is assumed to have existed before RNA. They also made a longer L-aTNA with a nucleobase sequence that complemented the sequences of the fragments, similar to how DNA strands match up. These L-threoninol nucleic acids both shorter and longer were placed in a test tube under controlled temperature. Researchers noticed that shorter fragments came together and linked with the longer L-aTNA. This happened due to the presence of N-cyanoimidazole, and a metal ion, like manganese, both of which were possibly present in early Earth.