In the world of microbes, genetic material is free to move from organism to organism. In more complex life, especially species that diverged on the tree of life long ago, this process becomes more and more rare. Scientists can now take genes and manually transplant them from one species to another, but, until now, nature wasn’t known to take the same liberties with DNA.
A sneaky sea slug is now throwing all of that out the window. Marine biologists once thought that Elysia chlorotica, a green marine slug, siphoned off chloroplasts from nearby algae to generate cellular power from the sun. Now, using radioisotopes to track molecules of chlorophyll inside the slug, researchers have discovered evidence that the slug not only steals the chloroplasts, but also replenishes the chlorophyll with its own internal processes.
This finding means that the slug has not only taken up structural/functional parts of the algae, but also some of the genes responsible for the production of chlorophyll (a process usually restricted to plants and few varieties of prokaryotes). While the exact nature of this cross-kingdom transformation has not been specified, the fact that evolution briefly “connected the tips” of two large branches of the living world may have important implications.
On the one hand, this kind of genetic cross-talk probably doesn’t happen very often – as kingdoms diverge they begin to take-up and use genes in more and more unique ways. That being said, the fact that it CAN happen in cases of close symbiosis like this one, may open up new lines of inquiry all over the natural world.
The second, and possibly more interesting possibility, is that investigating the mechanisms involved in this genetic transformation may lead to novel techniques and new ways of manipulating more familiar organisms…including us!
Want to know more about this slimy sea-beastie? Check out the wikipedia article for all the care and feeding!