Our marvelous small blue marble of an earth is loaded with an astonishingly diverse array of lifeforms, but some are certainly much more unusual compared to others.
This’s very true of the octopus, an animal so odd it frequently invites comparisons to aliens.
Certainly, when there’s some creature on Earth that is unusual adequate to possess developed elsewhere, based on British neuroscientist Anil Seth, it is the octopus. A few fringe theories even suggest that octopuses might be aliens.
Nevertheless, there is lots of proof to come octopus evolution securely to Earth, along with a group of researchers led by systems biologist Nikolaus Rajewsky of the Max-Delbrück-Center for Molecular Medicine just discovered a brand new body.
And it is an extremely fascinating one.
It is a characteristic which octopus brains really show human brains, as well as the brains of other vertebrates: an enormous repertoire of microRNA in the neural tissue of theirs.
“This,” Rajewsky says, “is what connects us to the octopus!”
Octopuses are odd in ways that are many. They are smart, also, as are also cephalopods, like cuttlefish. And squid brains are already discovered to be almost as intricate as the brains of dogs. There is even evidence to propose that octopuses can dream – seldom confirmed in invertebrates.
Compared with other intelligent animals, the nervous system of theirs is extremely distributed, with a major proportion of its 500 million odd neurons spread throughout the arms of theirs. Every arm is effective at making choices independently and may also still respond to stimuli after being cut.
The cephalopod complex central nervous system as well as the intelligence have been a bit of a puzzle. These characteristics are fairly common in vertebrates, but stick out among invertebrates.
Another thing concerning octopuses along with other cephalopods is actually strange. Their bodies can alter their RNA sequences easily to adapt to their environment. This isn’t how adaptation works in most instances; It generally starts with DNA and it is passed on to RNA after the changes are made.
This prompted Rajewsky to question what other RNA secrets may be concealed by octopuses.
Analyzing eighteen samples taken from dead octopuses – supplied by the Stazione Zoologica Anton Dohrn marine research institute in Italy – Rajewsky as well as his team sequenced RNA chiefly from Octopus vulgaris, the common octopus. The study was even carried out on a complete California two-spot Octopus (Octopus bimaculoides) in addition to a Hawaiian bobtail squid (Euprymna scolopes).
Sequencing produced a profile of messenger RNAs as well as tiny RNAs therein. The results were actually a shock.
“There was actually a great deal of RNA editing happening but not in places which we think to be of interest,” Rajewsky said.
The scientists discovered that octopuses have a great deal of microRNA. Within the typical octopus, 164 miRNA genes have been grouped in 138 miRNA families, along with 162 miRNA genes were grouped into the identical 138 families in the two-spot octopus of California. Plus forty two of the families were brand new, largely in neural tissue and the brain.
MiRNA are non-coding RNA molecules which are significantly associated with controlling gene expression, binding to bigger RNA particles to help cells fine tune the proteins they produce.
The reality that these miRNA families have been preserved in the octopus, along with RNA binding sites, suggests that they continue to be involved in octopus biology, even though scientists don’t yet know precisely what the role is or what cells the miRNAs are involved in.
“This is the 3rd largest expansion of microRNA households in the animal world as well as the biggest outside of vertebrates,” says Grygoriy Zolotarov, now at the Centre for Genomic Regulation in Spain, previously in Rajewsky’s laboratory.
To give you an idea of how large this species is, oysters, which are also mollusks, have acquired just 5 new microRNA families since the last ancestors they shared with octopuses, while octopuses have acquired ninety!
Just comparable expansions happened in vertebrates, even though the scale is a bit different. For context, the human genome encoding roughly 2,600 older miRNAS. The number of octopus miRNAs is, nevertheless, on par with those of other creatures, like chickens and frogs.
The finding indicates that complicated intelligence, such as cephalopod smarts, might be associated with this particular miRNA expansion, the scientists said.
Strangely enough, this isn’t the sole similarity between octopus as well as vertebrates brains. Scientists have discovered the brains of both octopus and human beings have a high number of transposons. The octopus head (and arms) appears to have a great deal more to it than we are able to understand.
The next phase for Rajewsky as well as his team is to find out precisely what those miRNAs are doing.
“The important explosion of the miRNA repertoire in coleoid cephalopods might suggest that miRNAs and possibly their specialized neuronal tasks are profoundly associated and perhaps necessary for the development of advanced brains in animals,” the authors write.
The research has been published in Science Advances.
