Origins Of Nervous System Found In Genes Of Sea Sponge

One of the things that's always fascinating (or inspiring, astonishing, awe-inspiring – take your pick) about what we learn from the evolutionary history of living critters is how much very different sorts of living things have in common. This even reaches down to the level of single cells, where very similar genes can be found in mammals and yeast, even bacteria.

We also find complex subsystems with substantial similarities. So much so that the nervous system of the roundworm Caenorhabditis elegans, which has all of 302 neurons in its whole nervous system (hermaphrodite version), is routinely used as an experimental model for the nervous systems of much more complex animals.

Perhaps even more astonishing than that, however, is that it now appears some genes important for modern nervous systems existed even before there were nervous systems – in sea sponges, which are just about the most primitive animals known.

Origins Of Nervous System Found In Genes Of Sea Sponge

Scientists at the University of California, Santa Barbara have discovered significant clues to the evolutionary origins of the nervous system by studying the genome of a sea sponge, a member of a group considered to be among the most ancient of all animals.

And not only are some of the genes there, but the proteins they represent may have interacted similarly to the way that corresponding proteins interact in modern synapses.

"It turns out that sponges, which lack nervous systems, have most of the genetic components of synapses," said Todd Oakley, co-author and assistant professor in the Department of Ecology, Evolution and Marine Biology at UC Santa Barbara.

"Even more surprising is that the sponge proteins have 'signatures' indicating they probably interact with each other in a similar way to the proteins in synapses of humans and mice," said Oakley. "This pushes back the origins of these genetic components of the nervous system to at or before the first animals ---- much earlier than scientists had previously suspected."

Other blog articles: here

Original research paper: here

Tags: synapses, neuroscience