Why do viruses mutate? | Science
Everything that depends on the genetic material is subject to mutations and mutations. Both SARS-CoV-2, which is an RNA virus, as we humans are made of DNA and RNA, are gradually changing. DNA (like RNA) is a massive molecule that is made up of the union of many other smaller molecules, which when placed in a row generate an enormous sequence. The arrangement of placing the pieces in the sequence results in text similar to the word made up of millions of characters. This text contains the instructions for operating its vector, whether it is a viral particle (every member of the virus army) or a human cell. We call the mutation a change of one or more characters within this mega scale. Sometimes this change modifies the meaning of the message and sometimes it is not in the same way that some errors in the written text are difficult to understand and some do not.
SARS-CoV-2 RNA contains about 30,000 LettersAnd one of the basic steps in the spread of the virus is to make copies of this huge for each of its future viral particles. To do this, once inside the infected cell, it uses a fairly accurate molecular camera, but everything has limits. Each viral particle can multiply thousands of times in a cell, it can infect millions of cells in the same individual, and if it causes a pandemic, it infects millions of people at one time. It stands to reason that with high activity, errors in RNA transcription occur, it is a matter of possibility. The more you copy something, the more likely you are to make mistakes. One can read his first eight titles from memory, but if he does so hundreds of times he will feel overwhelmed.
Thus, mutation is not an unexpected event, DNA and RNA are dynamic and mutable molecules that are frequently copied to perform their functions. They undergo changes, and transform, as part of their organic existence. DNA changes as well, and moles on the skin or cancer cells come from those inevitable mistakes. In fact, although we don’t call them mutations, it is the gradual changes in DNA that are responsible for changing us in relation to the pictures taken ten years ago.
DNA and RNA undergo aimless modifications. We may hear the phrase: “It is not surprising that viruses turn out to be more contagious,” but we must understand that these modifications do not happen with a purpose. The mutations are pre-adaptive, which means they happen by chance, then we’ll see what happens. If novelties make its bearer better survivor and easier to reproduce, it will tend to spread, and if it forms a burden, it will disappear. Therefore, the fact that the changes are random does not contradict the idea that more contagious viral variants appear more frequently. Virus RNA undergoes mutations, some produce infectious viral particles and others produce less.
Through pure competition, the most mobile people tend to eat the Earth the least. To illustrate graphically, if a viral particle puts its towel over its beachfront, there would be no other place, or at least it would be more difficult. In this way, it can be understood that viruses do not evolve to become more infectious, but rather that they mutate, and if they produce more infectious variants, we tend to notice their presence because they are more successful. Hence, in order to analyze the significance of mutation, first of all, it is imperative to be clear about whether or not it has an effect. For example, changing the word “car” to “automobile” in a sentence can be considered a change without effect. The equivalent mutation will not be a burden or benefit for the virus.
VUI-202012/01 variant of SARS-CoV-2 was recently described, increasing its relative presence, indicating that it is more contagious. Everything seems to indicate that the mutations you’ve been exposed to have had an effect. One of the changes in its transcript causes a slight modification of the segment that allows viral particles to bind to our cells, the S protein. In the viral particles carrying this new transcript, the new protein S is more efficient at binding to our cells, making it easier to enter. We can visualize it as more sticky, which is why it is more contagious: As it circulates through our respiratory passages, it immediately attaches to some of our cells to start infection.
So far we cannot confirm that mutations of this variable have other effects, but we can suggest a possible logical consequence: if it is proven to be indeed an infectious strain, it will continue to devour the Earth from others and increase its presence, and possibly the number of individuals infected. Fortunately, infection capacity is not associated with increased aggressiveness. In fact, when a highly aggressive variant arises, it tends to reduce its ability to infect, because if the sufferer is drastically put to bed, he will not be able to lead a rhythm of life that would allow them to be surrounded by people for contamination. In fact, aggressive ability and infection are often balanced, but we still do not know if this is the case with this variant. Indeed, initial results do not show significant differences in their aggressiveness. Of course, the gradual accumulation of mutations could also render the virus unknown compared to its predecessors, and it has changed as it did when we were five years old.
SARS-CoV-2 is not a particularly variable virus, some others, such as the influenza virus, mutate very quickly and every year they turn into a new enemy. Once again fortunately, none of the variants that emerged for SARS-CoV-2 appeared to undergo a major overhaul of its RNA. But at a time when the virus is spreading significantly, like the current one, the chances are that mutations will continue to appear. In short, we can say that SARS-CoV-2 is a highly contagious virus, and so far, it appears to be little mutated. However, the large number of cases is the best ally of future changes, and the best way to combat them is to reduce the rate of transcription. Right now it is not easy to avoid that, if it infects our cells, it is copied thousands of times and can mutate. But through our behavior we can avoid increasing the number of infected individuals, so it will definitely change less.
Miguel Peta He is a specialist in genetics, professor and researcher at the Autonomous University of Madrid. Is the author A day in the life of the virus (peripheral)