Cephalopods are, without a doubt, the most intelligent invertebrates with great abilities for learning and for solving problems of considerable difficulty. Now, a team of scientists from the University of Chicago and the University of California at Berkeley (USA) and the Okinawa Institute of Science and Technology (Japan) have succeeded in sequencing the complete genome of an octopus; It is therefore the first time that a complete analysis of a cephalopod has been carried out . The study has been published in the journal Nature .
Scientists have specifically sequenced the genome of the California two-spotted octopus ( Octopus bimaculoides ). The results have revealed unique genomic characteristics, which probably play a key role in the evolution of its particular traits such as its complex nervous system or its excellent camouflage ability. And it is that hundreds of specific genes of octopuses have been identified, many expressed in structures such as the brain, skin and suction cups.
“The octopus appears to be completely different from all other animals, even other mollusks, with its eight arms, large brain, and intelligent problem-solving ability, ” says study co-author Clifton Ragsdale.
The researchers estimate that the Octopus bimaculoides genome has about 2.7 billion base pairs and more than 33,000 protein-coding genes; it is therefore slightly smaller in size than the human genome but with more genes. Each base pair was sequenced 60 times.
Among the most striking findings of the octopus genome sequencing, the generalized genomic rearrangement stands out. In most species, the Hox genes – a group that participates in the development of organisms – are grouped together and control the bodily development of animals; however, scientists have found that in octopuses, these genes are scattered throughout the genome with no apparent links .
“With some notable exceptions, the octopus basically has a normal invertebrate genome that has been completely rearranged, as if they had been put in a blender and mixed.” This causes genes to be placed in new genomic environments, with different regulatory elements. , a totally unexpected finding ”, clarifies Caroline Albertin, co-author of the research.
