Little is known about the mysterious giant squid, a creature that was first captured on film in 2005. Now researchers have decoded the genome of the giant cephalopod, hoping to unravel more secrets about the legendary squid.
The study, published in Giga Science, notes that the giant squid has a huge genome with roughly 2.7 billion DNA base pairs. By comparison, humans have 3 billion DNA base pairs.
Caroline Albertin, one of the co-authors of the study, found that the developmental genes Hox and Wnt, seen in almost all animals, are also present in the giant squid genome, meaning its enormous size was not caused by an entire genome duplication.
“In terms of genes, we found the giant squid to be very similar to other animals,” Albertin said in a statement. “This means we can study these really strange animals to learn more about ourselves.”
The researchers also found more than 100 genes of the protocadherin family, 'not commonly found in abundance in invertebrates', in the genome of the giant squid.
“Protocadherins are believed to be important for the proper organization of a complex brain,” she added. 'They were considered a vertebrate innovation, so we were very surprised to find over 100 of them in the octopus genome (in 2015). They create a complex brain. And we found the same increase in protocadherins in the giant squid. '
“The genome is the first step towards answering many questions about the biology of these very strange animals,” said Albertin, including features such as the largest brain among invertebrates, their behavior and the ability to instantly disguise themselves.
Albertine also said that cephalopods are believed to have evolved independently of vertebrates, despite having many complex features. 'Comparing their genomes, we can ask:' Are the cephalopods and vertebrates built the same or differently? '
“Having this giant genome is an important knot in helping us understand what makes cephalopods molluscs,” she concluded. “And it can also help us understand how new genes arise in evolution and development.”
The largest giant squid ever recorded was 13 meters long and weighed nearly a ton, according to the Smithsonian Institution.
In June 2019, NOAA first saw the giant squid in US waters as part of what biologists have called the “most amazing video.” The giant cephalopod was sighted 160.93 km southeast of New Orleans.
Sources: Photo: Tsunemi Kubodera
