A University of Vienna study shows sea anemones use bone morphogenetic protein (BMP) shuttling to shape their bodies, a mechanism previously linked to bilaterians like humans.

Researchers note that cnidarians and bilaterians might have evolved similar bilateral traits independently, but Chordin-mediated BMP shuttling in both groups points toward a common ancestral origin for this developmental strategy.

BMPs act as molecular messages guiding embryonic cell fates, with gradient levels directing development of the nervous system, kidneys, and skin to shape the organism’s body plan.

The finding implies BMP-mediated body patterning existed before the cnidarian-bilaterian split, estimated at 600–700 million years ago, suggesting an ancient shared blueprint for axis formation.

Chordin, an BMP inhibitor that also serves as a BMP shuttle, helps create BMP gradients in sea anemones, mirroring bilaterian development and reinforcing an ancestral patterning mechanism.

The study suggests that even radically different organisms, from sea anemones to humans, may share deep evolutionary roots in how they establish body axes, challenging ideas about the timing of bilateral symmetry and complex patterning.