Humans might have evolved from apes, but that doesn’t mean we don’t share the same characteristics with other animals. A team of international researchers made a startling discovery when they found both the human and octopus brain share the same “jumping genes.”
“Jumping genes” are active in both the human brain and in the brain of two species of octopus — Octopus vulgarisms and Octopus bimaculoides. Over 45% of the human genome is composed by sequences called transposons, or the jumping genes, that can “move from one point to another of an individual’s genome, shuffling or duplicating.”
Researchers say these mobile elements usually remain silent and lost their ability to move. Others are inactive because they accumulated mutations over generations, while some are intact but blocked by cellular defense mechanisms.
According to researchers, the most relevant mobile elements belong to the Long Interspersed Nuclear Elements (LINE) family, which are found in 100 copies in the human genome and still potentially active. Scientists believe LINE “jumping genes” are associated with cognitive abilities like learning and memory.
Researchers say the octopus’ genome is also rich in jumping genes, which are mostly inactive. Researchers were able to identify “an element of the LINE family in parts of the brain crucial for the cognitive abilities of these animals.”
“The discovery of an element of the LINE family, active in the brain of the two octopuses species, is very significant because it adds support to the idea that these elements have a specific function that goes beyond copy-and-paste,” says Remo Sanges, director of the Computational Genomics laboratory at SISSA, in a statement.
Giovanna Ponte, from Stazione Zoologica Anton Dohrn, adds: “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 which in the octopus is the seat of learning and cognitive abilities, just like the hippocampus in humans.”
Researchers called it a “fascinating example of convergent evolution.”
“This similarity between man and octopus that shows the activity of a LINE element in the seat of cognitive abilities could be explained as a fascinating example of convergent evolution, a phenomenon for which, in two genetically distant species, the same molecular process develops independently, in response to similar needs,” said Giuseppe Petrosino, from Stazione Zoologica Anton Dohrn, and Stefano Gustincich, from Istituto Italiano di Tecnologia, in a statement.
The study is published in BMC Biology.