The marine invertebrate Hydractinia symbiolongicarpus, a colonial cnidarian that lives on rocks and shells in coastal oceans, must be able to defend its territory from other individuals without attacking itself in the process. A study published on September 26 in PNAS probed the underlying genetics of the animal’s allorecognition—the animal’s ability to distinguish itself from other members of the same species—and to the researchers’ surprise, the proteins involved in such recognition bear a striking resemblance to immunoglobulin proteins. The findings suggest that immunoglobulin genes evolved much earlier than previously thought.
“It is another milestone in our understanding of allorecognition in a cnidarian”, Ulrich Technau, a developmental biologist at the University of Vienna in Austria, who was not involved in the study, tells The Scientist over email. “[The study] is great, because it opens a completely new view on the subject, by combining genomics with novel structural biological methods.”
Hydractinia symbiolongicarpus ...
