British scientists have created synthetic DNA for colon bacillus

Creating artificial life is getting better and better. This time, we are talking about scientists from the University of Cambridge in Great Britain, who managed to create an organism with a completely artificial, computer generated DNA code, which is four times longer than previous experiments of this type.

Why did they do it? As scientists - to check something. In this particular case, it was intended to reprogram the DNA of Escherichia coli in such a way as to reduce the number of codons it uses. Managed to. Now let's talk about what it means and what actually happened.

Artificial DNA coding

The whole experiment began with the design of a new bacterial DNA code. The team of prof. Jason China used a computer model for this purpose, thanks to which scientists could form a completely new configuration of four nucleotides: adenine (A), thymine (T), guanine (G) and cytosine (C), which are the basis of the DNA code of all organisms on our planet . Differences between these organisms arise from the different order of arrangement and the length of the DNA strands created from these four letters .

It's best to think of the DNA itself as a source code or as a sequence of commands. The stored sequence of nucleotides determines the structure of proteins created in cells, which means that it determines the construction ... well, everything that lives. The color of your hair or eyes is stored somewhere in all this tangle of nucleotides. The transport of this information from DNA to cell ribosomes (proteins are made there) deals with mRNA ( messenger-RNA) , or ribonucleic acid that acts as a carrier of the source code to the cells.

Codons, nucleotides and amino acids

Ok, let's get back to the source code itself. A single instruction in DNA is called a codon. A codon is nothing more than three consecutive nucleotides: AAT, GTA, CCG, etc. Each combination (a total of 64) is responsible for the production of one of the 20 amino acids from which the Earth's proteins are built. Here, too, there is a problem that scientists from the University of Cambridge have decided to address.

You see, if the whole process of evolution is considered a real masterpiece, then delving into its details very quickly you can find quite controversial patents . Take, for example, such an Escherichia coli bacterium. In its DNA code there are as many as six instructions (ie codons) responsible for the production of serine (it is such a protein) and three instructions with the STOP command, which are attached at the end of the production code for individual amino acids.

Cleaning the DNA code

Where did so many instructions responsible for the same activities come from? It is not known. Evolution goes along twisting paths. Besides, the complexity of the DNA code, even in the simplest organisms, quite effectively makes it difficult for us to get to know this mechanism through. For example, the bacterium examined by the China team has 18214 codons in its DNA. Without a computer, tracing such a long sequence would probably take several years. And I would like to remind you that we are talking about a relatively less complicated bacterium. In man, this number will be much higher.

But returning to the Escherichia coli - the British managed to completely redesign the DNA in such a way to get rid of the extra-curricular, duplicate instructions for the production of serine. In practice, this meant finding 18 thousand. places in the bacterial DNA and substitution of the TCG codon on the AGC, which does the same. By the way, we managed to get the third STOP instruction, leaving only two. Thanks to these treatments, a new bacterium, equipped with modified DNA, was built using only 61 codons instead of 64.

Well, good. And what?

Well ... for now we know that this modified organism works. It is true that the bacterium with reprogrammed DNA is a bit longer and grows a bit slower, but in addition, scientists have not noticed any changes in its functioning as yet. However, the changed growth rate and length are still a puzzle - probably in the code of the original there is some undiscovered dependence, about which we have no idea yet.

And that was actually the goal of the whole experiment. Check whether the body with a slightly shortened (we talk about the number of codons) the DNA code is able to work, just like the original. The researchers are also convinced that thanks to such experiments they will be able to learn all the nuances and dependencies of existing DNA. And if they succeed, they will be able to improve and clean the code itself. One of the hypotheses, repeated in the environment of genetic engineers, says, for example, that by reprogramming DNA we will be able to create proteins that have never been seen in nature before. For now, however, we do not know if such an action will make sense.

The discovery may (in the long run) interest the pharmaceutical industry

The selection of Escherichia coli is not accidental. Already, its modified versions are used in the pharmaceutical industry for the production of insulin. And now this method is slowly becoming insufficient. The research shows that in 2030, in other words, for (less than) 11 years, the need for insulin will significantly exceed the capacity of its production. The researchers warn that of about 79 million patients with type 2 diabetes, only 38 million will have access to it.

Perhaps the British experiment will result in the development of a more efficient bacterial species. Besides, the team of prof. China is not the only group that is currently trying to dig in the DNA code. Harvard scientists are working on creating bacteria with even more code changes. It is impossible not to mention the disgraceful Chinese experiment, in which one of the local doctors has modified (although much smaller) the DNA code in human embryonic stem cells, thus wanting to make them immune to HIV.

Getting to know all the secrets of our DNA code will allow us to improve what little by little and by chance have managed to create an evolution. Unfortunately, to do it right, we still have many years of research, trials and mistakes.

British scientists have created synthetic DNA for colon bacillus