Microbiologists seem to have solved the mystery of the "chicken and egg"

In science, a popular theory that the first life on Earth appeared in the so-called "primary soup". The broth elements on the basis of carbon were joined together in simple molecules, while not ultimately laid the Foundation for the emergence of primitive life. But a further step in the evolution of causes among scientists a lot of controversy and debate.

According to one popular hypothesis, the molecules of ribonucleic acid (RNA) containing the genetic code for proteins and are capable of performing the functions of the simple chemical reactions were those that marked the beginning of life on our planet. Some scientists reject this idea and say that the RNA is too large and complex structure in order to have the right to wear the title of catalyst life. According to these scientists, even before the emergence of macromolecules in the form of RNA is more simple molecules were able to develop the ability to use metabolic function, without which no RNA would not exist. Overall, the idea acts because the head of all, that is the first appeared metabolism. New evidence of the scientific group from the University of Illinois only reinforce that idea.

"All living creatures have a metabolism, a set of vital chemical transformations, allowing to provide these organisms with energy and matter, necessary for the functioning of cells. These metabolic transformations likely appeared on Earth very early. It is possible that the first organisms had borrowed the chemical reaction has already been available at that time on the planet, having learned them in the cells through the development of enzymatic activity", — says Gustavo Caetano-Anolles, bioinformatic and Professor of plant breeding Department of the University of Illinois.

Caetano-Anolles and his colleague Ibrahim koç from Turkish Technical University Gebze decided to test the theory of "primary metabolism" through the analysis of molecular functions of organisms in all kingdoms, and studied genome (set of genes) 249 individual organisms, the details of which are in the project database "". This unique database makes the fact that it contains not only information about each of the products of genes – proteins or RNA molecules, but also a description of the functions of each individual gene in these organisms.

"You can take the whole genome, represented in the organism, e.g. human, and visualize it using the set function features of each individual gene. The study of these "functional" can tell you about what makes a particular gene. For example, we can figure out what type catalytic recognizing or binding functions has a specific gene product that is much more intuitive for the research" — says, Caetano-Anolles.

"the Best way to understand a living organism – to find out the functions of its genes" — scientist continues.

According to Caetano-Anolles, there is a same function in the genome in different species could indicate the evolutionary importance of this function. Therefore, the researchers studied all of the molecular function parse organisms, counted them, and brought those that were met in all cases. The basic idea behind it, is that the first, i.e. the most basic features such as catalytic processes responsible for the emergence of metabolism, most likely, was endowed with all organisms of the time and therefore are discovered throughout the so-called tree of life. At the same time, the functions of the genes that appeared after all the others, on the contrary, will be encountered in a smaller number of species.

With the help of modern information and computer techniques, the researchers created a tree depicting the path leading to the underlying molecular features. Closer to the base of the tree (i.e. closer to the roots) are the most ancient function. More «fresh» functions of, in turn, are closer to the apex.

It Turned out that at the base of this tree it is possible to allocate only two molecular functions that, most likely, and marked the beginning of life on Earth. Is the metabolism and molecular bonds.

"it is logical to assume that these two functions came first. As molecules for energy production was necessary metabolism. In addition, they needed to interact with each other", — explains Caetano-Anolles.

The Following features implemented that made possible the emergence of macromolecules. This may appear RNA. Next, the mechanisms that allowed the molecules to integrate into the cells, and then functions that allow cells to interact with each other and their environment.

"In the end, getting closer to the crown of a tree, we can see functions related to complex processes, including the production of muscle, skin or nervous system," — said Caetano-Anolles.

Their study, the researchers not just to shed light on the past life. Recall that evolution is still ongoing. Therefore, understanding the sequence of formation of these molecular features through time can help us to predict where life on Earth moves on.

"When people talk about evolution, they look back. We also would like to develop a chronological and methodological models that could answer the question of whither the evolution and emergence of any new molecular functions, we ought to expect from it in the future," — says, Caetano-Anolles.

Today's professionals will definitely be able to find its application in bioengineering, developing the use of biological information and computing to create new biological forms. According to Caetano-Anolles, development of new genes in the future will be able to root to solve problems of various diseases and improve our daily lives.

"the Key to effective restructuring of our genome and providing it with new useful molecular functions is to understand the principles of operation of simple molecular forms of life in the past" — concludes the scientist.

The Original article, Caetano-Anolles and Ibrahim Koch entitled "the Natural history of molecular functions on the basis of an extensive phylogenetic data analysis gene ontology" was published in the journal PLoS One.