Human genetic engineering has always been a hot topic in science fiction, and genetic engineering to optimize the goal is nothing more than a few, people become more healthy, smarter, stronger, more beautiful and so on. Unfortunately, now we are not aware of the various functions of the gene, a lot of so-called "optimization" if it is not in the science fiction works, it is likely to be a hoax.
However, scientists in this area is constantly working hard last month by the Lawrence Berkeley National Laboratory scientist Axel? Visel (Axel Visel) organized by the scientific research team published in the "Science" magazine on a Studies have shown that by editing some of the mouse regulatory fragments, one can influence the final born mouse skull shape, giving the mouse "cosmetic". This brings some inspiration to people, and perhaps also makes us a little step closer to optimizing human beings through genetic engineering.
To use genetic engineering to mice "cosmetic", first of all to determine what parts of the mouse start. Wessel They did not proceed directly to the gene as most people did, but aimed at the DNA fragments of the control gene - the enhancer.
Before we further explain what the Vessel team has done, please let me first use a metaphor to explain what the enhancer is in the end.
In each cell, there are a number of different chromosomes, each one is like a long hanging axle (please imagine a few thousand kilometers long hanging axle). Gene is painted on the hanging axis of the drawings, records the cells and biological individuals need a variety of information, a hanging shaft may have a lot of such drawings, dozens of hundreds of thousands have, but each hanging axis On the fact that only a small part of the area draw a drawing.
When the cells need to use the contents of the drawings, it will send a copier - known as RNA polymerase protein, specifically to the axis of the copy of the drawings (known as gene transcription), and the finished product to the downstream to achieve Various functions (synthetic protein, etc.). However, the copier itself does not know where to print the hanging shaft, so the front of each drawing has some specific markings - called the promoter - meaning "there are drawings, quick copies" and cells There are also various guides - proteins called transcription factors that recognize these markers, which guide the copier to complete its copying work.
However, the cells also need to control the speed of copying a variety of drawings, so many promoters do not say "speed to copy", but only that "there are drawings", as to whether to copy, more subtle. At this time, another mark on the hanging axle - called the enhancer - comes into play, and some of the enhancer is similar to the "quick to copy a sheet of 100 meters or less." In this case, the wizard recognized the contents of the enhancer, it will pull the enhancer to find the corresponding promoter, and finally guide the copier copy the corresponding drawings.
Promoters and enhancers are all fragments of chromosomes, but are generally outside the gene (the promoter is on the head of the gene, and the enhancer may be far from the gene), since their role is to control the gene The level of transcription, so people put them into the "regulatory fragment." It should be noted that the specific details of how the gene is regulated, which enhancers and which promoters interact with each other, and so on, there are still many unsolved mysteries.
Wieser's research team to take the enhancer as a research object, need to overcome several problems: First, how to find the enhancer? Secondly, how can we find that the enhancer is effective? They first found the enhancer of the mouse embryonic skull by locating the specific transcription factor that had been bound to the enhancer on the chromosome. After the use of transgenic means, in the vicinity of the enhancer inserted in the promoter will react with the promoter and the subsequent chromogenic genes (equivalent to the effective description of the enhancer description, insert a copy will change after the color of the drawings). In this way, if the enhancer is effective in the skull, the skull of the transgenic mouse embryo that is made will produce a protein for color development that can be seen under a microscope. Through this technique, they not only determined that the enhancer was effective in the head of the mouse embryo, but also found that different enhancers would function in different areas of the head (see below). After this two-step experiment, the Vesel group identified 55 enhancers that worked in the mouse's head development.
Found 55 enhancer, the next step is of course try to move if the move, the mouse will become like a. The researchers identified three of the 55 enhancers (three in Figure 1), using genetic engineering to knock them out and make three different transgenic mice.
And then run into another problem: each mouse in the eyes of ordinary people are about the same length, probably only very familiar with the mouse researchers may distinguish between the differences between them; and even if the distinction between the need to put these differences After quantification, it is convenient to measure the effect of each enhancer.
To solve this problem, the researchers carried out a skull tomography of three transgenic mice and control mice, and established a three-dimensional model of each mouse skull. After that, they simplified and classifies these three-dimensional models by mathematical methods, and established a three-dimensional coordinate system (described below) that describes the mouse skull. By putting the skull shape of each mouse into the coordinate system, we can see that the knockout of each enhancer causes the mouse skull to differ from the normal mouse shape and knock out the different The effect of enhancers on mouse skull shape is not the same. Of course, this is to make the mouse changed the United States or become ugly, have to ask the mouse to determine (perhaps the animal behavior will be a good subject).
This groundbreaking study combines several techniques to bring a lot of inspiration for future research: the location of enhancers and the determination of enhancer activity can help us reveal the mysteries of many cell regulatory genes; The quantification of the shape of the mouse skull is to give a further study, and even the practical application of the future to determine an operational standard - the future scientists may first want to do the mouse shape first quantified according to this standard, and then through Control a series of enhancers to produce mice with specific head types.
Finally, there is still a few words to say: this study is undoubtedly in the initial stage, from the free manipulation of the mouse head type there is a considerable distance from the free to the human plastic surgery to optimize the next generation is far worse. So it is a pity, if there are prospective parents want to put their future children through genetic engineering into a handsome girl, or to rethink what is good, so as not to delay. Moreover, even in the distant future of this technology can be successfully applied to people, we all look like almost no better?