Part of the show Search for Extraterrestrial Life
You’ve heard of the body-snatchers, but what about the gene-snatchers ? Biologists at the University of South Florida studying the DNA blueprint of the sacoglossan sea slug (Elysia crispate) were surprised to find that the slug appears to have stolen some of its genes from the algae it eats. Algae are tiny water plants that, like plants on land, contain chloroplasts, nature’s solar cells, which they use to harness sunlight to make energy. When the slugs eat the algae the cells lining their intestines pick up the chloroplasts, intact, and use them. In fact, if you shine light on the slug it produces oxygen and takes up carbon dioxide, like a plant does ! The chloroplasts survive inside the slug cells for several months and even continue to make proteins. And it was when they studied the slug’s DNA blueprint, that researcher Skip Pierce and his team found the slug carried a gene coding specifically for one of these chloroplast proteins. So how did the slug steal the gene ? At the moment the team aren’t sure, but they suspect that a virus might be responsible. The team hope that by learning how nature has produced its own genetically modified slug (which contains algae genes !) we might be able to use the same molecular subterfuge to improve our current gene therapy techniques.