Dresden 2026 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 14: Poster Session II

BP 14.53: Poster

Dienstag, 10. März 2026, 18:00–21:00, P2

Chimeric RNA-DNA Oligomers Overcome Template-Product Inhibition in Prebiotic Ligation — •Lena Mühlschlegel, Ludwig Burger, and Ulrich Gerland — Physics of Complex Biosystems, School of Natural Sciences, Department of Bioscience, Technical University of Munich, Garching, Germany

The RNA world hypothesis proposes that DNA-based life evolved from a precursor living system that used RNA alone to store genetic information. However, it is unclear how the transition from a system purely based on RNA to one incorporating DNA could have occurred. At the transition, a lack of specificity in the synthesis of genetic polymers in prebiotic systems likely led to the simultaneous emergence of RNA and DNA, involving molecules comprising RNA-DNA nucleotides, which we refer to as chimeric RDNA strands. Because homogeneous RNA-RNA and DNA-DNA duplexes are highly stable, template-product inhibition can impede template-directed ligation. Experimental data show that RDNA-DNA or RDNA-RNA duplexes tend to be less stable than RNA-RNA and DNA-DNA duplexes, suggesting that RDNA strands might overcome template-product inhibition. We developed a nearest neighbor model parametrized by experimental data to predict RDNA hybridization energies as a function of sequence and used it to simulate template-directed ligation of RNA and DNA in the presence and absence of RDNA strands. We found a hybridization free energy regime in which RDNA strands enable the efficient replication of RNA and DNA, providing a potential pathway for the early evolutionary transition from RNA to DNA.

Keywords: Emergence of life; RNA world hypothesis; Nucleic acids; Template-directed ligation; Hybridization free energy