The first genetically-altered squid has scientists thrilled about a potential new way to study the intriguing cephalopods, a group including octopus, cuttlefish, and squid.
Creatures that have famously complex brains, the largest of all invertebrates, and behavior including the ability to camouflage themselves (despite being colorblind) count, recognize patterns, problem solve, use tools, mimic other species and communicate using a variety of signals.
These distinctive features attract the attention of many biologists and open many avenues for study and have applications in a wide range of fields, from evolution and development to medicine, robotics, materials science, and artificial intelligence.
To achieve this biological breakthrough, the team used CRISPR-Cas9 genome editing to knock out a pigmentation gene in squid embryos, which eliminated pigmentation in the eye and in skin cells resulting in the edited squid being mostly transparent instead of having its usual dark spots.
Starting by working on the alteration of a squid’s pigmentation gene was a logical point of departure for experimentation since the species in question show small dark spots on their skin which, if missing, are easy to detect and keep track of.
The ability to knock-out a gene to test its function is an important step in developing cephalopods as genetically tractable organisms for biological research, increasing the very special list of model organisms that currently dominate genetic studies, such as fruit flies, worms, and mices.
Furthermore, the researchers are also looking to add in genes, rather than just knocking out existing ones, a necessary step toward having the capacity to knock in genes that facilitate research, such as those which encode fluorescent proteins that can be imaged to track neural activity or other dynamic processes.
Unfortunately, the longfin inshore squid, the species used for this research, isn’t amenable to being raised to maturity in the lab since it gets too big. But there are plenty of other, smaller squid and octopus species, and the team is already working to transfer the technology to the ones they’re cultivating in captivity.
The milestone study, the first gene knockout in a cephalopod using the squid Doryteuthis pealeii, was led by a team at the Marine Biological Laboratory (MBL) led by Senior Scientist Joshua Rosenthal and MBL Whitman Scientist Karen Crawford.