After several years and numerous conference calls with international experts, a group of scientists were able to finish mapping the entire genome of the octopus. The task wasn’t easy but researchers now hope to use the acquired genomic data to find some answers to very old questions regarding the animal.
The genome sequence was a joint effort of scientists from the U.S., Germany, and Japan, and a study on it was first published this week in the journal Nature.
Caroline Albertin of University of Chicago and co-author of the study explained that the octopus has a very complex DNA structure.
The team had to first obtain a species of octopus that is very easy to breed in laboratory conditions. They chose the California two-spot octopus as their subject because its offspring reach very fast maturity. Though the project lasted several years, the results were rewarding.
The team found that the tiny animal has a huge genome, with 2.7 billion base-pairs, while humans have about 3 billion. But researchers ruled out the possibility of duplication, a theory that past studies had promoted. To put it simpler, the animal never doubled its genome. It was able to develop more genes from start.
On the other hand, researchers agreed that the creature had identical pairs of specific regions of the genome. The large amount of genes may also help researchers better understand why these marine creatures are so smart. Scientists are especially interested in one set of genes called protocadherins.
Protocadherins are known to help the development of brain and nervous system. And the octopus has plenty of these genes – about 170, which is nearly ten times more than an invertebrate should have, and nearly double the number in vertebrates.
Albertin likened the newly found genes with a “genomic smoking gun” that may help scientists learn why the animal is so intelligent.
But the research team also found that the octopus’s genetic code is abundant in transposons, or “jumping genes.”
These genes provided the animal’s genome with some out-of-this-world features. For instance, scientists compared the genome with that of an invertebrate mixed in a blender so that usual genes occupy unusual places and may be responsible for unusual functions.
The team expects that these weird genes may help them understand what genetic underpinnings may be behind the animal’s unique physiological and behavioral features.
“A genome represents the molecular toolbox available to an animal, so it gives you a catalog of all of the genes that there are, and where they’re expressed,”
She also added that “the toolbox” can now help scientists decipher what function each gene has within the genome of the bizarre animal.
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