Squid and human brains develop similarly despite diverging 500 million years ago

Squid and human brains develop similarly despite diverging 500 million years ago

It is a rather surprising discovery that relates the site live science, on Monday January 16, 2023, relaying a study published in the journal Current Biology last December. Scientists have brought to light an unexpected link between humans and… squid! By observing this animal, they would have discovered that “the brain of cephalopods evolved independently to develop in the same way as ours”.

To study the brains of developing squids at the embryonic stage, the scientists used snapshots using cameras. To visualize the stem cells of interest, they marked them with fluorescent dyes. It was the retinas, and more specifically the neural tissue therein, that caught the eye of the experts.

The construction of the nervous system

For Kristen Koenig, a molecular biologist at Harvard University, this discovery is simply exceptional: “Our conclusions were surprising because much of what we know about the development of the nervous system in vertebrates has long been considered to be specific to this line.” And the main author of the study clarified: “Observing the fact that the process is very similar, what he suggested to us is that these two [lignées] independently developed very large nervous systems using the same mechanisms to build them. What this suggests is that these mechanisms in animals during development may be important for building large nervous systems.”

The importance of studying the diversity of life

“One of the great lessons of this type of work is how valuable it is to study the diversity of life,” enthuses Kristen Koenig. Before concluding: “By studying this diversity, you can really come back to fundamental ideas, even about our own development and our own relevant biomedical questions.”