The octopus is a unique creature with an extremely complex brain and cognitive abilities unique among invertebrates. In a way, this animal has more in common with vertebrates. Of course, the evolutionary reasons for octopus intelligence and the molecular mechanisms that determine this are still being investigated.
A new study published in the journal Biomedical Central Biology suggests that the neural and cognitive complexity of octopuses may arise from molecular similarities to the human brain. The research is a result of a collaboration between the Italian School of Advanced International Graduate Studies, the Anton Dorn Institute of Zoology and the Italian Institute of Technology.
Have a “jumping gene”
In 2001, the sequencing of the human genome found that more than 45% of the genome consists of sequences called transposons. These DNA sequences, known as “jumping genes”, are able to move from one location in the genome to another: through molecular mechanisms of “copy and paste” or “cut and paste”, enabling duplication or mixing.
Most of the time, these mobile elements are inactive. Sometimes this is because mutations accumulated over generations have eliminated their ability to move, and other times it is because cells apply protective mechanisms to hold them back and disable their ability to move.
The study shows that the same jumping gene is active in both the human brain and the brains of two species of octopus: the common octopus and the California two-spot octopus. According to experts, the discovery may shed light on the mysteries of the intelligence of this fascinating creature.
”It was previously known that the octopus genome is rich in transposons, but potential transposons have never been found in this animal,” Remo Sanjes, director of the Computational Genomics Laboratory at the Advanced International Graduate School, told the Spanish news agency Information and Technology. Active elements.”
Possess cognitive ability
Among the different types of transposons, the transposons belonging to the “LINE” family are the most expressed in the human genome, that is, long scattered repeat sequences.
Traditionally, LINE’s activities have been viewed as mere remnants of the past, a legacy of an evolutionary process involving these mobile elements. But new evidence has emerged in recent years that LINE activity is finely regulated in the human brain.
In fact, they are particularly active in the hippocampus, a structure important in the human brain for neural control of the learning process. This evidence has led many scientists to link them to cognitive abilities such as memory.
The researchers looked at those transposons that still have the ability to copy and paste, and have identified elements of the LINE family in parts of the octopus brain that are critical to the octopus’ cognitive abilities.
The results are significant.
Through the application of next-generation sequencing technology, people were able to analyze the molecular composition of active transposons in the octopus nervous system.
”The discovery of active LINE family elements in the brains of the two species of octopus studied is very interesting and supports the idea that these elements have specific functions beyond copy and paste,” Sanjes said.
”The vertical lobe is the brain structure that houses learning and cognition in octopuses, like the hippocampus in humans,” explains Giovanna Ponte of the Anton Dorn Institute of Zoology. I literally jumped on my chair when the LINE elements in the region signaled very strong activity.”
”Octopuses and humans are the only two species that can observe LINE element expression in the ‘lobes’ that control cognitive abilities .” Biology,” Sanchez said.
According to Stefano Gustinchik of the Italian Institute of Technology and Giuseppe Petrosino of the Anton Dorn Institute of Zoology, “This similarity between humans and octopuses or could be interpreted as an excellent example of convergent evolution, the phenomenon in which the same molecular evolutionary process independently develops in response to similar needs in two genetically distant species.”
