Carl Zimmer in his excellent blog, The Loom:
A couple days I introduced an awesome sea slug that eats algae and uses them to become photosynthetic. I thought it would be worth revisiting this marvelously plant-like animal for a couple reasons. One is that I’d like an excuse to post this excellent photo, which is on the cover of the latest issue of the Proceedings of the National Academy of Sciences, where a new paper on the sea slug is being published (photo by Mary Tyler). Another reason is that I wanted to relay an email exchange I had with the lead scientist on the study, Mary Rumpho.
Rumpho discovered that the sea slug has incorporated a key gene for photosynthesis from the algae into its own DNA. That means that the slugs don’t just passively let the photosynthesizing structures from the algae (called plastids) harness sunlight. The slugs themselves actually make proteins that are essential for photosynthesis.
I wondered how in the world a gene from algae got into the slug’s own DNA.
More here.