Scientists have already established that octopuses are smarter than your average invertebrate, but a new discovery suggests one of the reasons: a specific molecular analogy with the human brain.
Both the human genome and the octopus genome contain a large number of “jumping genes” or transposons, which are capable of duplicating or moving through the genome. Although not all of them are active, these transposons are considered raw materials for evolutionary processes.
In a new study, transposons belonging to the LINE (Long Interspersed Nuclear Elements) family have been discovered in the part of the octopus brain that manages cognitive skills, a place similar to where they can be found in the human brain.
“I literally jumped on the chair when, under the microscope, I saw a very strong signal of activity of this element in the vertical lobe, the structure of the brain that in pop is the seat of learning and cognitive abilities, just like the hippocampus in humans, ”says biologist Giovanna Ponte of the Stazione Zoologica Anton Dohrn research institute in Italy.
Recent research has revealed how LINE transposons are carefully regulated in the human brain, and are thought to be related to learning and memory, in part because they are more active in the hippocampus, from where they control processes. learning.
By finding these jumping genes in the same brain location of two species of octopus: the common octopus (Octopus vulgaris) and the California octopus (Octopus bimaculoides), the researchers believe they may have found a key reason behind the high intelligence. license shown by these genes. sea creatures.
Although transposons are known to use molecular mechanisms to copy and paste and cut and paste, the study suggests that there are more things here: that there is a direct relationship to the complexity of the nervous system, including the brain.
“The discovery of an element of the LINE family, active in the brains of the two species of octopuses, is very significant because it adds support to the idea that these elements have a specific function that goes beyond copying and pasting,” says Computational . the genomist Remo Sanges of the research institute Scuola Internazionale Superiore di Studi Avanzati in Italy.
In addition, researchers think we might be looking at an example of convergent evolution: when similar traits develop independently in completely unrelated species and provide the same adaptation, which in this case are superior cognitive abilities.
Scientists continue to find evolutionary tricks and neurological responses that make octopuses stand out among invertebrates and make them more similar to mammals in terms of brain structure and activity.
“The brain of the octopus is functionally analogous in many of its characteristics to that of mammals,” says biologist Graziano Fiorito of the Stazione Zoologica Anton Dohrn.
“For this reason, too, the identified LINE element represents a very interesting candidate to study to improve our knowledge of the evolution of intelligence.”
The research has been published in BMC Biology.