For the first time it was "counter" to turn on and off genes – and scientists are developing traumes of cellular nanoobots
For many purposes, it could be highly practical if you can not only plant genes in body cells, but they could turn on or off as needed, as well as that happens. A first success in the development of such a taxable "genetic circuit", whose targeted control was opened by numerous applications, now scientists of the center for biodynamics (cbd) have been achieved at boston university.
Genes are not only information units that contain commands, such as producing a particular protein or rna, but there are also the regulatory genes that, often enough in a complicated hierarchical cascade sequence, control the activity of other genes by either turning them on or their activity underprere if certain proteins are present in the cell. These control proteins, which are bound by the dna, can in turn be activated by the prasenz of certain chemical connections or by the temperature.
A few possibilities are already known as how the presence of certain chemical connections some genes can be permanently switched on or off. For most cases of gene therapy, however, can not only be crucial to introduce a structural gene into the genome of certain cells, as it usually arrives that the gene produces the right amount about proteins at the right time. New to the development of researchers who describe them in nature is just this possibility of repeating or deactivating genes by a short stimulation of genes.
The "counter" have developed the scientists from genes of the bacterium escheria coli by putting two pairs of complementary genes – repressors and promoters – so together that only one gene can be active in each pair. By an exuberant influence, in this case the presence of tetracycline or the increase of the temperature, then dear this genetic switch. In order to check the effectiveness, the scientists also introduced a much used jellygen that produces a green fluorescent protein when it is "switched on" is. Even if the chemical substance no longer exists or the temperature was resumed, the circuit remained stable: "control circuits, which are stable both on the on and off position, is in natural form in very specialized genetic systems", explains james collins, director of the cbd and co-author of the publication. "But this is the first time that one could produce an artificial bistable on / off switch to control the expression of a gene." the genetic switch developed by the scientists is allegedly used in many genes in different organisms and also in human cells.
As the next step, the scientists want one "genetic sensor" making to turn genes on or off when a particular concentration of a chemical substance is in the cell. Developed is already a genetic sensor for glucose, which could be used to treat diabetes. In the first phase, the color of a small skin surface could be changed if the blood sugar content utilizes a certain concentration to remind the patient that they must take their insulin. Ultimately, the cellular insulin production should be regulated with it.
But the scientists see a variety of applications. Thus, the switches according to their ideas could be used, for example, in genetically changed bacteria, which are used for biodegradation of certain substances. Bacteria that can implement ol, they love to program so that they recognize with their genetic sensor, which amounts of ol have to be degraded to orient their behavior. Timothy gardner, another co-author, said you can program you so program that you can donate yourself if no ol is available anymore. Built-in in human cells, the genetic sensors, which sounds even more about science fiction, can also be used to detect biological weapons to warn people or even stimulate the cells to produce an antidote. Since you are already in the middle of a biological rising spiral.
The fantasies of the scientists are still further: the genetic switch konne may also serve as an element of an artificial cellular memory to produce cell-based computers. In turn, the basis for nanorobotic could be in the form of a cell or a network of cells: "since richard feynman’s visionarem proposal in 1959, to build submicroscopic machines technically, the idea of nanorobotists has fumbled the imagination of scientists", so gardner. "In recent years, this possibility was mostly associated with micro-electromechanical machines. We suspect that nanoroboters can have a ‘weterme’ form, especially those of a living cell. Ultimately, we introduce ourselves to a combination of genetic switches, genetic sensors, sequential expression networks and other machines in a ‘genetic applet’, a fully-stadnically programmable genetic network for controlling cell functions."
Until then, the way will be a long time. The genetic sensor for glucose, however, the scientists want to have already realized in one year.