Liquid Crystal Phases of DNA, Beginning of Life?

An anonymous reader writes "A team led by the University of Colorado at Boulder and the University of Milan has discovered some unexpected forms of liquid crystals of ultrashort DNA molecules immersed in water, providing a new scenario for a key step in the emergence of life on Earth. CU-Boulder physics Professor Noel Clark said the team found that surprisingly short segments of DNA, life's molecular carrier of genetic information, could assemble into several distinct liquid crystal phases that "self-orient" parallel to one another and stack into columns when placed in a water solution. Life is widely believed to have emerged as segments of DNA- or RNA-like molecules in a prebiotic "soup" solution of ancient organic molecules.

Comments

neat

[wizardforce]

"The key observation with respect to early life is that this aggregation of nano DNA strands is possible only if they form duplexes," Clark said. "In a sample of chains in which the bases don't match and the chains can't form helical duplexes, we did not observe liquid crystal ordering."

The CU-Boulder and University of Milan team began a series of experiments to see how short the DNA segments could be and still show liquid crystal ordering, said Clark. The team found that even a DNA segment as short as six bases, when paired with a complementary segment that together measured just two nanometers long and two nanometers in diameter, could still assemble itself into the liquid crystal phases, in spite of having almost no elongation in shape. Subsequent tests by the team involved mixed solutions of complementary and noncomplementary DNA segments, said Clark. The results indicated that essentially all of the complementary DNA bits condensed out in the form of liquid crystal droplets, physically separating them from the noncomplementary DNA segments. "We found this to be a remarkable result," Clark said. "It means that small molecules with the ability to pair up the right way can seek each other out and collect together into drops that are internally self-organized to facilitate the growth of larger pairable molecules. "In essence, the liquid crystal phase condensation selects the appropriate molecular components, and with the right chemistry would evolve larger molecules tuned to stabilize the liquid crystal phase. If this is correct, the linear polymer shape of DNA itself is a vestige of formation by liquid crystal order."

one of the requirements for life is that you have an environment that supports molecular self assembly and recognition, this experiment seems to show that this is the case with DNA and RNA strands as short as 6 bases and can select for more stable configurations over time. It's the beginnings of evolutionary natural selection- base pairs assemble into structures that have certain desireable characteristics.

Re:not intelligent enough...

[Anonymous Coward]

However, religion bashing has come to a point where even admitting of being religious is a cause of ridicule or arrogance. Gee I wonder why? Oh that's right, it's because most often "your religion" has some pretty nasty things to say about the rest of us. Such as suffering in eternal agony unless we reciprocate the love of your god or prophet. When was the last anti-Buddhist rant you've heard or read? Ever? Stop trying to pass off being spiritual as having an organized set of beliefs that you must adhere to and coerce others to adhere to as well. I consider myself a very spiritual person but I'm still an atheist and an agnostic. It's not bashing of beliefs, customs or traditions, it's the rational rejection of questionable claims. God has never claimed to exist. It's not like God is the shining sun, I can feel the heat and I can see the light but I'm just some asshole rejecting it. I'm not walking around tripping over God and then willfully disbelieving out of spite or arrogance. The existence of God is non-obvious, therefore the burden of proof remains squarely on those making the claims, no matter what kind of flawed thought-process you follow. As for my idea of "God" it's more of a nomological necessity similar to the fundamental force of gravity rather than a personal deity with two eyes, ears, arms, legs and testicles. Seriously, that idea of a god that your parents taught you out of an uncorroborated book written by Stone Age peasants is laughable and you really do only deserve ridicule and shame, if and only if you've been presented with all this evidence and still hold true that Jesus Christ is the only way God could come up with to save us from his dysfunctional Universe.

And if you don't like it, fuck you.