A study from the University of South Florida and the University of Maryland, College Park (USA) has discovered how it is possible that a bright green sea slug can live like a plant , feeding only on sunlight. The work has been published in the journal The Biological Bulletin .
The slug in question is Elysia chlorotica , it has an appearance that resembles that of a vegetable leaf , it measures only six centimeters and its natural habitat is the coasts from Nova Scotia to southern Florida. It feeds on an alga called Vaucheria litorea from which the slug has decided to “borrow” its chloroplasts to carry out photosynthesis.
To reach this certainty, the researchers discovered that the slug had learned to digest the algae without damaging the essential chloroplasts (integrating them into its digestive cells), which transform sunlight into food, since it has genes from the algae that are essential to maintain in good condition the chloroplasts of this. This is the first case of functional genetic transfer from one multicellular species to another (known as horizontal gene transfer), making this small slug the first and only animal capable of carrying out the photosynthesis process .
“This work confirms that one of the algae genes necessary to repair damage to chloroplasts and keep them functioning is present on the slug’s chromosome. The gene is incorporated into the slug’s chromosome and passed on to the next generation. ” The offspring only have to ‘steal’ the chloroplasts from the algae, as the genes to maintain chloroplasts are already present in the slug genome. It’s impossible for algae genes to work inside an animal cell, and yet here they do , says study co-author Sidney K. Pierce.
