I had never really considered the octopus to be intelligent. Little did I know they are unlike any animal on this planet.
For starters, the DNA of an octopus contains nearly 10,000 more gene codes than that of a human. Various clusters of these gene codes perform different tasks—and octopus genes are specially equipped to do very versatile things. For instance, six different octopus gene codes combine to produce an octopus’s ability to rapidly camouflage itself. Another gene type, protocadherin, allows the development of neurons and neural transmissions.
Most mammals, including humans, only have 70 or so protocadherins. The octopus has 168. And the octopus has one of the largest gene families devoted to development of any animal we’ve mapped so far—second only to the elephant.
Strange octopus genome
Alien roots? Most likely no but…
With its eight prehensile arms lined with suckers, camera-like eyes, elaborate repertoire of camouflage tricks and spooky intelligence, the octopus is like no other creature on Earth.
Added to those distinctions is an unusually large genome, described in Nature1 on 12 August, that helps to explain how a mere mollusc evolved into an otherworldly being.
“It’s the first sequenced genome from something like an alien,” jokes neurobiologist Clifton Ragsdale of the University of Chicago in Illinois, who co-led the genetic analysis of the California two-spot octopus (Octopus bimaculoides).
From another source.
The first whole genome analysis of an octopus reveals unique genomic features that likely played a role in the evolution of traits such as large complex nervous systems and adaptive camouflage. An international team of scientists sequenced the genome of the California two-spot octopus – the first cephalopod ever to be fully sequenced – and mapped gene expression profiles in 12 different tissues. The findings are published in Nature on Aug 12, 2015.
The researchers discovered striking differences from other invertebrates, including widespread genomic rearrangements and a dramatic expansion of a family of genes involved in neuronal development that was once thought to be unique to vertebrates. Hundreds of octopus-specific genes were identified, with many highly expressed in structures such as the brain, skin and suckers.
The results serve as an important foundation for evolutionary studies and deeper investigations into the genetic and molecular mechanisms that underlie cephalopod-specific traits. The work was conducted by teams from the University of Chicago, University of California, Berkeley and Okinawa Institute of Science and Technology as part of the Cephalopod Sequencing Consortium.