Scenario Created for First Life on Earth

U.S. and Italian scientists have found forms of liquid crystals of DNA molecules immersed in water yield a new scenario for the emergence of life on Earth.

The team, led by the University of Colorado-Boulder and the University of Milan, found ultrashort DNA segments can assemble into several distinct liquid crystal phases that self-orient parallel to each other and form columns when placed in a water solution.

University of Colorado-Boulder physics Professor Noel Clark said the study shows that in a mixture of tiny fragments of DNA, those molecules capable of forming liquid crystals selectively condense into droplets in which conditions are favorable for them to be chemically linked into longer molecules with enhanced liquid crystal-forming tendencies.

We found even tiny fragments of double helix DNA can spontaneously self-assemble into columns that contain many molecules, Clark said. Our vision is that from the collection of ancient molecules, short RNA pieces or some structurally related precursor emerged as the molecular fragments most capable of condensing into liquid crystal droplets, selectively developing into long molecules.

The study appears in the Nov. 23 issue of Science.