A Potentially Kleptoplastic Sea Slug

Scientists suspect that the green sea slug (Elysia chlorotica) is guilty of kleptoplasty—the stealing of genetic material from another organism. For some time, experts have known that the green sea slug acquires chloroplasts from the algae it eats. The sea slug stores those chloroplasts in cells that line its gut. There, they act as miniature powerhouses, converting sunlight into sugar. Yet scientists have been puzzled as to how the chloroplasts continue to function on their own. The DNA inside the stolen chloroplasts encodes only about one tenth of the proteins needed to keep it running. So chloroplasts alone do not give the sea slug the ability to photosynthesize.

Research by green sea slug expert Mary Rumpho of the University of Maine may point to the missing piece of the puzzle. Rumpho's observations suggest that the green sea slug may also be stealing nuclear DNA from the algae (in addition to chloroplasts). The sea slug then may be incorporating the algae's DNA it into its own genetic material so it can synthesize the proteins the stolen chloroplasts need to function.