Viruses - The hackers of the nature

Viruses are famous for the speed at which they evolve – with which the infected organisms have to keep up. The researchers have now found the mechanism by which organisms manage to keep up with viruses' variability.

Viruses are the simplest living creatures – in fact they are so simple that it isn't even clear whether they are indeed alive. A virus is simply a relatively complex chemical compound which is pushed around at random, which doesn’t feed itself and doesn't even multiply by itself. What sets it apart from other chemical substances is that when it ends up inside a cell it hijacks its internal machinery and "uses" it for producing other versions of itself. An infected cell is destroyed as it cannot fulfill its usual tasks.

For protecting against viruses, the plants' and animals' cells developed various defense mechanisms at the entrance in the cell. Their problem is that they cannot

simply stop all substances entering the cell, because they need such exchanges to survive. Thus, the cells need to filter the good substances (the nutrients they need) from viruses.

The difficulty is the following: When they multiply, the cells have a much smaller variability than viruses. In fact, cells even have certain mechanisms that correct the mutations that may appear during the cell division process, mechanisms that assure the copy resembles the original as closely as possible. As the cells are more complex than a virus, any mutation may be damaging, so they developed mechanisms to prevent mutations. But viruses don't have such mechanisms – there isn't any place where they could keep such a mechanism because they are nothing but the code which copies itself.

The cells are thus in a paradoxical situation: if their mutation-correction mechanisms are too efficient they are overwhelmed by viruses, but if their mutation-correction mechanisms is too weak they break down due to damaging mutations.

The viruses are like a sort of hackers that succeed breaking the code at the cell's entrance, and in order to survive the cells have to change these "codes" sufficiently fast.


The researchers at Edinburgh University, Dr. Darren Obbard, Dr. Tom Little and their colleagues have discovered how organisms adapted to their paradoxical situation: the genes that control the immunitary system have the highest variability – they are among the genes that change fastest – while the genes that control other aspects of the cell (such as methabolism) are prevented from mutating too fast. The genes that control other genes are thus specialized and make a distinction between virus protection and the rest.

Researchers have found that the genes that control the genes containing the "recipe" for the immunitary system are much more affected by mutations compared to the genes that control the genes containing other "recipes". This is how cells are able to cope with the variability of viruses.

This discovery is interesting also because it gives some clues about how life managed to evolve further than simple unicellular organisms. Without such a fast changing protection against viruses, life couldn't have developed into more complex forms – any complex cell would have been destroyed by viruses.

 

Wow, someone actually started a thread about something other than weed or songs. And it can be no surprise that up to this point no one has commented on this thread.

I would just like to say that I've always had an interest in viruses. In biology class in high school I was amazed by the fact that viruses are not alive or dead. That in itself is a kind a paradox.

It seems that you are saying that it is our immune system that really has protected us for so long. By having certain genes such as the immune system changing fast while keeping the genes of the metabolism slower, a kind of equilibrium is maintained within the body which keeps viruses from winning. Because some genes are faster than others, the body is not overrun by viruses, but it is not also not damaged by mutations.

Based on your post, it makes sense why AIDS is so difficult to stop. AIDS destroys the immune system, and eradicates the equilibrium that exists between the genes of the immune system and the genes of the metabolism and other slow genes.

Once that balance is disturbed, other viruses can come in and competely take over the organism.

Here is the thing that boggles my mind. If the virus is not alive or dead, what is the purpose of it "hacking" into a cell? What does the virus get out of it? Survival? Viruses aren't really like parasites, so that are not merely infiltrating cells for survival, are they? If they aren't really alive, what does survival mean to them?

The only answer I can think of is that viruses infilitrate cells for the same reason many hackers infiltrate computer networks, because they want to get information. I don't mean to say that viruses are intelligent, but perhaps they want to become a part of a higher organism, but by becoming a part of that organism they destroy it. Now this post is starting to sound philosophical.