Octopuses can change their own DNA information as a strategy for evolution, which may be the reason for the intelligence and complex behavior of these cephalopods.
Not only the octopuses, but also the squid, among other animals in the cephalopod family, are able to alter the information carried by the genes themselves, a study published this week in the scientific journal Cell.
These animals (marine mollusks) do not follow the rule of information stored in their DNA, thus having the ability to interfere and change that information in a possible evolutionary strategy that may justify their high intelligence and complex behavior, scientists believe. This is only possible when the organism produces a molecule that diversifies the proteins generated by the cells, inducing variations of genetic information.
To be able to understand this phenomenon, it is necessary to evaluate two distinct concepts, DNA and RNA. The first, deoxyribonucleic acid, is a double helix chain that carries all the genetic information that makes each individual unique. For example, the color of the eyes, the tone of the skin or even the natural predisposition for a particular disease. These are individual features that are provided by DNA.
RNA, ribonucleic acid, is formed only by a strand and is much smaller than DNA, since it is only a copy of a segment of DNA, from which it is synthesized in a process of name, transcription. One of the main functions of RNA is to carry instructions from a specific part of the genes and deliver them to the cells to produce the proteins of the organism.
What the octopuses do is to modify the RNA that is stored in the nuclei of the brain cells, instead of inducing mutations directly in the DNA. Thus, the body will produce proteins different from those previously provided and will induce variations of the genetic information that lead the cells to do something different than had been instructed by the DNA.
But it is not yet clear in what circumstances these animals put this strategy into practice, although scientists believe that this factor can justify the intelligence and complex behaviors of the octopuses.
This mechanism had already been identified in other animals, including humans, but never studied and evaluated with the size found in cephalopods.
Whereas in people and fruit flies this modification of the genetic material occurs in only 1% of the time that the body transcribes RNA from the DNA in the dusts and squids, this strategy was observed in 60% of the time in the cells of the brain.