New study hints at spontaneous appearance of primordial DNA

The image shows a droplet of condensed nano-DNA and within it smaller drops of its liquid crystal phase which show up in polarized light on the left. The liquid crystal droplets act as “micro-reactors" where short DNA can join together into long polymer chains without the aid of biological mechanisms. Image courtesy Noel Clark, University of Colorado

The image shows a droplet of condensed nano-DNA and within it smaller drops of its liquid crystal phase which show up in polarized light on the left. The liquid crystal droplets act as “micro-reactors” where short DNA can join together into long polymer chains without the aid of biological mechanisms. Image courtesy Noel Clark, University of Colorado

The self-organization properties of DNA-like molecular fragments four billion years ago may have guided their own growth into repeating chemical chains long enough to act as a basis for primitive life, says a new study by the University of Colorado Boulder and the University of Milan.

While studies of ancient mineral formations contain evidence for the evolution of bacteria from 3.5 to 3.8 billion years ago — just half a billion years after the stabilization of Earth’s crust — what might have preceded the formation of such unicellular organisms is still a mystery. The new findings suggest a novel scenario for the non-biological origins of nucleic acids, which are the building blocks of living organisms, said CU-Boulder physics Professor Noel Clark, a study co-author. Continue reading New study hints at spontaneous appearance of primordial DNA


A Lamp Whose Light Comes From Bioluminescent Bacteria

Ocean waves glowing blue in the dark of night, anyone who has ever experienced this knows how magical it looks. The phenomenon is caused by bioluminescent micro-organisms in seawater that emit light when provided with oxygen every time a wave turnes. This principle inspired Teresa van Dongen to combine her passion for design and biology in a bioluminescent light installation. Ambio balances two weights and a glass tube half-filled with a “Artificial Seawater Medium” containing a carefully selected type of these unique luminescent species. Give the lamp a gentle push every so often and the weights will keep it moving and thus glowing. Ambio is a visualization of a research on how to use nature as a source of energy.


Slow Life

“Slow” marine animals show their secret life under high magnification. Corals and sponges build coral reefs and play crucial roles in the biosphere, yet we know almost nothing about their daily lives. These animals are actually very mobile creatures, however their motion is only detectable at different time scales compared to ours and requires time lapses to be seen.
This clip, as well as stock footage, is available in UltraHD 4k resolution. Make sure you watch it on a large screen! You won’t be able to appreciate this clip or see individual cells moving in a sponge on a smartphone.

Chemists create ‘artificial chemical evolution’ for the first time

ncomms6571-f1Scientists have taken an important step towards the possibility of creating synthetic life with the development of a form of artificial evolution in a simple chemistry set without DNA.
A team from the University of Glasgow’s School of Chemistry report in a new paper in the journal Nature Communications today (Monday 8 December) on how they have managed to create an evolving chemical system for the first time. The process uses a robotic ‘aid’ and could be used in the future to ‘evolve’ new chemicals capable of performing specific tasks.
The researchers used a specially-designed open source robot based upon a cheap 3D printer to create and monitor droplets of oil in water-filled Petri dishes in their lab. Each droplet was composed from a slightly different mixture of four chemical compounds.
Droplets of oil move in water like primitive chemical machines, transferring chemical energy to kinetic energy. The researchers’ robot used a video camera to monitor, process and analyse the behaviour of 225 differently-composed droplets, identifying a number of distinct characteristics such as vibration or clustering.
The team picked out three types of droplet behaviour – division, movement and vibration – to focus on in the next stage of the research. They used the robot to deposit populations of droplets of the same composition, then ranked these populations in order of how closely they fit the criteria of behaviour identified by the researchers. The chemical composition of the ‘fittest’ population was then carried over into a second generation of droplets, and the process of robotic selection was begun again. Continue reading Chemists create ‘artificial chemical evolution’ for the first time

Electron Handedness Affects Gas Molecule Breakup

Experiments show that beams of left- or right-handed electrons are not equal-opportunity destroyers of molecules having two mirror-image forms, which supports the idea that primordial cosmic rays generated the asymmetry in biological molecules.

An asymmetric reaction billions of years ago between electrons and the ancestors of biomolecules might explain why today’s DNA always appears as a right-handed helix. Now researchers have shown that a beam of right-handed electrons—whose spin and direction of motion align according to the right hand—breaks apart more right-handed molecules at low energies than left-handed ones. Unlike previous experiments showing such a difference, the reactions occurred in the gas phase and with low-energy electrons, which allowed for a more precise description of the electron-molecule interactions. The researchers say their results are an important step toward more direct tests of the hypothesis that nuclear asymmetries led to asymmetries in present-day biomolecules.

Many molecules come in both left- and right-handed (chiral) forms, but natural DNA is always right-handed. The asymmetry “is one of the few unsolved fundamental questions in [the] natural sciences,” says Uwe Meierhenrich, a physical chemist at the University of Nice Sophia Antipolis in France.

One possible explanation comes from nuclear physics. The radioactive decay of a nucleus is more likely to produce a left-handed electron than a right-handed one—meaning that it’s more likely to spin in the direction of your left hand’s curled fingers when you point your left thumb in the direction of its motion. When this asymmetry was discovered in 1957, “it showed us that God is not ambidextrous,” says Timothy Gay of the University of Nebraska in Lincoln. Continue reading Electron Handedness Affects Gas Molecule Breakup

Information Theory And The Origin of Life

Christoph Adami
Research investigating the origins of life usually focuses on exploring possible life-bearing chemistries in the pre-biotic Earth, or else on synthetic approaches.
Little work has been done exploring fundamental issues concerning the spontaneous emergence of life using only concepts (such as information and evolution) that are divorced from any particular chemistry.
Here, I advocate studying the probability of spontaneous molecular self-replication as a function of the information contained in the replicator, and the environmental conditions that might enable this emergence.
I show that (under certain simplifying assumptions) the probability to discover a self-replicator by chance depends exponentially on the rate of formation of the monomers.
If the rate at which monomers are formed is somewhat similar to the rate at which they would occur in a self-replicating polymer, the likelihood to discover such a replicator by chance is increased by many orders of magnitude.
I document such an increase in searches for a self-replicator within the digital life system avida …
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Why an extra helix becomes a third wheel in cell biology

dna3Every high school biology student knows the structure of DNA is a double helix, but after DNA is converted into RNA, parts of RNA also commonly fold into the same spiral staircase shape.

In a literal scientific twist, researchers are finding examples of a third strand that wraps itself around RNA like a snake, a structure rarely found in nature. Researchers recently have discovered evidence of a triple helix forming at the end of MALAT1, a strand of RNA that does not code for proteins. Yale postdoctoral fellow Jessica Brown and her colleagues working in the labs of Joan A. Steitz and Thomas A. Steitz describe the bonds that maintain the structure of a rare triple helix.

This extra strand of RNA, which is seen in the accompanying movie, prevents degradation of MALAT1. The formation of a triple helix explains how MALAT1 accumulates to very high levels in cancer cells, allowing MALAT1 to promote metastasis of lung cancer and likely other cancers.

The work is published in the journal Nature Structural and Molecular Biology.