Mysterious Giant Squid's Genome Unveiled

The legendary giant squid has reached school-bus size with eyes as big as dinner plates and tentacles that can snatch prey 10 yards away. The University of Copenhagen-led team that includes scientist Caroline Albertin of the Marine Biological Laboratory (MBL) found the full genome sequence of the mysterious giant squid (Architeuthis dux).

According to study author Caroline Albertin, "We have so much to learn about the living world. Much of the world is covered in ocean, and we know relatively little about the deep sea, where these animals live." She said we can learn about how they solved the challenges of living in that environment.

The team of scientists has put together a preliminary reconstruction of the giant squid's full genome sequence.

Last 2015, Albertin also led a research project that constructed the first genome of a cephalopod (octopus, squid).

She noted that in terms of their genes, the giant squid looks a lot like other animals, meaning they "can study these truly bizarre animals to learn more about ourselves."

The giant squid's genome is predictably consisting of an estimated 2.7 billion DNA base pairs, making it about 90% the size of the human genome.

While there is more to learn about this near-mythical beast, a genome is a first step for answering several questions about its biology, said Albertin.

Information is still elusive about the giant squid, due to its skittish nature and because it lives at such great depths. In the past years, researchers have collected only relatively few remains of giant squids from around the world.

The genome sequence can provide important insight into their biology (even how they reproduce) which is still a mystery.

Through mitochondrial DNA sequences, researchers previously confirmed that all giant squids belong to a single species.

According to Tom Gilbert, a professor at the GLOBE Institute, their initial genetic analysis generated more questions than it answered.

More than 100 genes in the protocadherin family -- typically not found in abundance in invertebrates -- were identified in the giant squid genome.

The research team was led by Rute da Fonseca at the University of Copenhagen.

Albertin drew comparisons with several ancient, well-known gene families in the giant squid and four other cephalopod species that have been sequenced and with the human genome.

Cephalopods are presumed to have evolved independently from vertebrates.

The giant squid looks a lot like other animals; Hox and Wnt were especially two developmental genes that are found in almost all animals.

The project's most notable finding was that within the giant squid, essential developmental genes that are found almost universally in all animals were only present in single copies. Thus, giant squids did not develop to such an unbelievably large size through the process of whole-genome duplication.

The team identified a group of genes called reflectins, which are only known to exist in cephalopods. Albertin said that reflectins encode a protein that is involved in making iridescence.

The giant squid genome was said to be crucial in helping the researchers understand what makes a cephalopod a cephalopod.

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