[/]: How life on earth began? this is a doesnot science topics. It can be used to manufacture their own copy of elements considered essential to the understanding of this process, because they provide life one of the important features of the system — — genetic basis. Recently, the United States Scripps Research Institute scientists of new discoveries, in response to how life began on the biochemical problems has taken an important step, they first without any protein and other cell components, synthesize RNA can be self replication and replication can go on indefinitely.
The study results published in the recently published in science magazine.
In the modern world, DNA carrying advanced life of genetic sequences, DNA and RNA dependent to fulfil their tasks, such as the synthesis of proteins. However, a major theory of the origin of life — the RNA world model, because RNA enzyme with gene and at the same time, DNA RNA may precede and protein, and play the life of the ancestor elements of this important role. However, copy a genetic molecular processes, is considered an essential condition of life, as it involves a large number of proteins and other cell components, the replication process is extremely complex.
For years, researchers have always wanted to know about the existence of some of their own by RNA replication RNA simple way. Previously there had been a researchers along this route did some exploratory work, but no one can prove that the RNA replication is the proliferation of self, that is a copy of the new RNA can also copy itself.
In vitro evolution of RNA enzyme
Scripps Research Institute of Trish · Lincoln and her teacher Professor Steven Gerrard · Joyce has been studying RNA replication concepts (RNA-onlyreplicationconcept). They started using an in vitro evolution is a well-known force the adaptation, the goal is to take an already developed in the lab can complete the basic chemistry of replication of RNA enzyme, and improvements to drive efficient and permanent self replication. Lincoln completed this challenging work, she in the laboratory synthesis of RNA enzyme variants, after a test tube evolutionary process, from the RNA enzyme variants will gain the most adept at RNA fragments together variants.
Ultimately, this process allows the isolation of the study group on RNA enzyme of an original evolution version, this version is a very efficient replication, this is including Joyce, many research teams strive hard for many years trying to get something. This improved RNA enzyme to complete the first task is to make the copy permanent. Lincoln said, this result is all her own.
Molecular genetic information of enduring
Replication system actually involves two enzymes, enzyme consists of two subunits, each of the enzymes are used as catalysts to assemble a different enzyme. The replication process is circular, in this process, the first enzyme and composition of the second of two subunits, and connect it to form a second copy of a new enzyme; at the same time, the second enzyme is also the first enzyme do the same work. In this way, two enzymes are assembled each other, using the terminology called crossover copy. You only need a small amount at the beginning of the two enzymes and stable supply of subunit, unlimited cross-replication. Joyce said, this is in addition to the molecular biology information only available forever.
Researchers has not stopped, they established with similar functionality in a variety of enzymes on (enzymepairs). They are 12 kinds of crossover copy on, along with its all subunits of the composition of the blend, let them in a survival of the fittest molecules in competing. In most cases, these replicase proliferation will be correct, but sometimes replicase can make mistakes, a subunit and other copy from a subunit. When this kind of "mutation" occurs, the resulting recombinant enzymes also continuous replication, but the most suitable replicase number will more and more, always occupies a mixture of domination.
Research has shown that the system can maintain molecular genetic information, and to a similar to Darwin evolutionary manner causing itself changes. Therefore, Lincoln said: "our existing research objects are lifeless, but we have been able to demonstrate their own similar to life character, this is very interesting. ”
Tapping the door of the life
The historical origins of life has never been accurately rebuild, so if you do not have a reliable time machine, it necessarily raises another related issues: whether life is maybe has been created in the lab. Of course, this may reveal life may begin, at least in outline. Lincoln such review their work, "we do not attempt to rewind the tape, but related research may be able to tell you how to begin to understand the emergence of life in the lab, a new process."
Joyce said, only when a laboratory-developed system has in itself developed on the basis of the capacity of the new features, it can be called a so-called life. "We're tapping the door of the life of this sector, but we have not yet reached this point."
Research team creates transcriptase enzyme, each of which contains a number of the nucleotide, therefore these subunits is rather complex. Although infrastructure seems to be very simple, but this final show, an RNA-based more simple form of life is possible, at least, this will certainly promote the researchers more in-depth exploration of the origin of life theories of RNA world model.
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