Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Life’s origins were easier than was thought

16.09.2005


According to the most accepted theory on the origin of life, life began with very simple molecules, RNA chains, which were able to self-replicate. The problem with the theory, however, is that the fragility of these chains when there are replication errors (mutations) made it almost impossible for them to have evolved into more complex life forms. An international team of scientists, including Universitat Autònoma de Barcelona researchers, has discovered that these early molecules were much more resistant than was thought until now. According to the conclusions of the study, they may have developed enough to contain around 100 genes, which is considered to be the minimum quantity required for the most basic forms of primitive life, similar to the bacteria we have today. The research was published in the September edition of Nature Genetics.



In the primordial soup that produced life on earth, there were organic molecules that combined to produce the first nucleic acid chains, which were the first elements able to self-replicate. According to one of the more accepted theories, these molecules were ribonucleic acid (RNA) chains, a molecule that is practically identical to DNA and that today has the secondary role in cells of copying information stored in DNA and translating it into proteins.

These proteins have a direct active role in the chemical reactions of the cell. In the early stages of life, it seems that the first RNA chains would have had the dual role of self-replicating (as is today the case with DNA) and participating actively in the chemical reactions of the cell activity. Because of their dual role, these cells are called ribozymes (a contraction of the words ribosome and enzyme). But there is an important obstacle to the theory of ribozymes as the origin of life: they could not be very large in length as they would not be able to correct the replication errors (mutations). Therefore they were unable to contain enough genes even to develop the most simple organisms.


An investigation led by Mauro Santos, from the Department of Genetics and Microbiology at the Universitat Autònoma de Barcelona, alongside two Hungarian scientists, has shown that the error threshold, that is, the maximum number of errors that may occur during the replication process of ribozymes without this affecting its functioning, is higher than was previously calculated. In practice, this means that the first riboorganisms (protocells in which RNA is responsible for genetic information and metabolic reactions) could have a much bigger genome than was previously thought: they could contain more than 100 different genes, each measuring 70 bases in length (bases are the units that constitute the genes and codify the information), or more than 70 genes, each measuring 100 bases. It is worth remembering that tRNAs (essential molecules for the synthesis of proteins) are approximately 70 bases long.

The discovery has greatly relaxed the conditions necessary for the first living organisms to develop. “This quantity of genes would be enough for a simple organism to have enough functional activity”, according to the researchers. Recent analysis into the minimum number of DNA genes required to constitute bacteria, the most simple organism today, considers that around 200 genes is sufficient. But in riboorganisms there can be much fewer genes, since DNA genomes include a number of genes that have the role of making the RNA translation system (which enables proteins to be produced) work, which would not be required in RNA-based organism.

Octavi López Coronado | alfa
Further information:
http://www.uab.es/uabdivulga/eng
http://www.uab.es

More articles from Life Sciences:

nachricht Researchers develop eco-friendly, 4-in-1 catalyst
25.04.2017 | Brown University

nachricht Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017
25.04.2017 | Laser Zentrum Hannover e.V.

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

NASA's Fermi catches gamma-ray flashes from tropical storms

25.04.2017 | Physics and Astronomy

Researchers invent process to make sustainable rubber, plastics

25.04.2017 | Materials Sciences

Transfecting cells gently – the LZH presents a GNOME prototype at the Labvolution 2017

25.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>