Squid are among the smartest ocean dwellers. Along with other ink-squirting cephalopods like octopuses and cuttlefish, squid boast the largest brains of all invertebrates. They also have an incredibly complex nervous system capable of instantaneously camouflaging their bodies and communicating with each other using various signals. From a report: Scientists have long marveled at these sophisticated behaviors and have tried to understand why these tentacled creatures are so intelligent. Gene editing may be able to help researchers unravel the mysteries of the cephalopod brain. But until now, it’s been too hard to do — in part because cephalopod embryos are protected by a hard outer layer that makes manipulating them difficult. Recently, a group of marine scientists managed to engineer the first genetically altered squid using the DNA editing tool CRISPR. In addition to being a big milestone in biology, the advance has potential implications for human health: Because of their big brains, cephalopods are used to study neurodegenerative diseases like Alzheimer’s and Parkinson’s.
The ability to edit the genes of these animals could help scientists study the genes involved in learning and memory as well as specific cephalopod behaviors. “I think you’re going to see a huge jump in the use of these [gene-edited] organisms by neurobiologists,” Joshua Rosenthal, PhD, a senior scientist at the Marine Biological Laboratory in Woods Hole, Massachusetts, and a key architect of the first genetically engineered squid, tells OneZero.
Rosenthal and his colleagues used CRISPR to snip out a gene responsible for the coloring of the squid’s skin. As a result, the edited squid were transparent instead of having their usual reddish spots. The results were published July 30 in the journal Current Biology. But why bother to create a colorless squid? Rosenthal says the pigmentation gene was a logical starting place for experimentation. “If you see the pigmentation go away, it’s easy to see if the gene editing is working,” he explains. Being able to tinker with cephalopod DNA will allow scientists to better study what their individual genes do at a very basic level. The accomplishment wasn’t easy. Scientists have successfully made gene-edited mice, monkeys, and other research animals to help them study a range of behaviors and medical conditions. But until now, they hadn’t been successful at manipulating the genes of cephalopods.