[ad_1]
Scientists at the Center for Molecular Biology Severo Ochoa and the Technical University of Delf (Netherlands) realized in a test tube that a "minigenome" expresses the proteins that reproduce it again and again. again.
they know how the components of the cell work separately, but by putting them to work all at once, the complexity exceeds their current knowledge. Fotolia
The badembly of the first synthetic cell is a challenge of the current biology that scientists have barely managed to approach. Its realization would not only challenge the science we take for granted today, but could also open up a range of possibilities, both in terms of knowledge and practical applications.
To build a synthetic cell, there are many systems They must work perfectly and be coordinated. We know more or less how the components of the cell work separately, but by putting them to work at once, the complexity exceeds our current knowledge.
However, there are a number of pillars from which you can build. On the one hand, one of the key functions to include in an artificial cell is the replication of genetic material. On the other hand: it is necessary that this genetic material be expressed, and the way it does it by the production of a messenger (mRNA), being necessary proteins that make that the instructions of this message are fulfilled. Finally, a membrane separating the cell from the outside would be necessary
Using the Phi29 bacterial virus, a minigenome could express the proteins that replicate it again and again
In this context, a collaboration between scientists from the Technical University of Delft (Netherlands) and the Margarita Salas laboratory of the Center for Molecular Biology Severo Ochoa (Madrid-CSIC) realized in the test tube that a & # 39; minigenome & # 39; expresses proteins They reproduce it again and again. These results, published in Nature Communications demonstrate the possibility of mimicking the replication function of genetic material, which is an important step in the construction of the first synthetic cell, according to the authors.
The team implemented Phi29 virus DNA replication machinery in a cell-free gene expression system. The laboratory of Christophe Danelon in Delft is focused on the implementation of this minimal system in vitro and on the replication of DNA, its transcription into RNA, the translation of the RNA in proteins encoded by said DNA, and that these proteins in turn replicate the original DNA.
Many methods have been described in which transcription and translation are performed simultaneously, the key being the DNA replication system. One of the simplest, best described and most effective DNA replication mechanisms is that of the Phi29 bacterial virus, the linear genome protected by the terminal protein.
Information on the DNA Replication System
For its part, the laboratory of Margarita Salas is the one that has provided the vast majority of knowledge on this system of replication of DNA. # 39; DNA.
The collaboration between the two groups allowed Dr. Danelon's laboratory to make good use of Phi29's DNA replication machinery. This team optimized a transcription-translation reaction so that by adding to this reaction a linear minigenome coding for proteins essential to DNA replication of Phi29, these proteins were produced and immediately started to act on the minigenome that coded them. copies of the same, with which the cycle could be considered closed.
The generated minigenomes are functional and in the presence of appropriate components return to produce replication proteins
"But not only, but it was found that in turn, the new minigenomes produced were fully functional and, in the presence appropriate components, they came back to produce the replication proteins and replicate again, "describe the authors of the work. "In addition," they added, "we performed this type of cycle three times in a row, purifying the mini-genomes and transferring them to new reactions that provided all the necessary components without the replication proteins. "
For the purpose of a synthetic cell, Dr. Danelon's laboratory understood the complete reaction described in the liposomes that simulated the cell membrane. Thus, it was observed that, again, the reaction was carried out, the replication proteins were produced and these replicated the DNA.
Even though there is still a long way to go to get a cell that lives, grows and divides into daughter cells, this work represents a decisive step in that direction. In addition to reproducing the genetic material, the method would incorporate new functions such as membrane production, cell division, energy production, metabolism, and so on.
These functions would be incorporated as DNA modules that would encode the corresponding proteins. they would add the initial minigenome to make it more like a cell. Another function that could be included is Darwinian evolution based on mutations and the selection of the most suitable individuals.
Source link
