Researchers have found a new map of the octopus genetic code that is so strange that it could be actually be an “alien”.
The first whole cephalopod genome sequence shows a striking level of complexity with 33,000 protein-coding genes identified – more than in a human.
The octopus DNA is highly rearranged – like cards shuffled and reshuffled in a pack – containing numerous so-called “jumping genes” that can leap around the genome.
“The octopus appears to be utterly different from all other animals, even other molluscs, with its eight prehensile arms, its large brain and its clever problem-solving abilities,” said US researcher Dr Clifton Ragsdale, from the University of Chicago.
“The late British zoologist Martin Wells said the octopus is an alien. In this sense, then, our paper describes the first sequenced genome from an alien.”
The scientists sequenced the genome of the California two-spot octopus in a study published in the journal Nature.
The scientists estimate that the two-spot octopus genome contains 2.7 billion base pairs – the chemical units of DNA – with long stretches of repeated sequences.
And although the genome is slightly smaller than a human’s, it is packed with more genes.
A gene is a region of DNA that contains the coded instructions for making a protein.
There are no such groupings of genes with related functions. For instance, Hox genes – which control body plan development – cluster together in almost all animals but are scattered throughout the octopus genome.
It was as if the octopus genome had been “put into a blender and mixed”, said co-author Caroline Albertin, also from the University of Chicago.