A mating swarm of the marine choanoflagellate S.
To the surprise of scientists, bacteria can act as an aphrodisiac for the one-celled marine organisms that are the closest living relatives of all animals.
This is the first known example of bacteria triggering mating in a eukaryote, a group that includes all plants and animals. The organisms, protists called choanoflagellates, eat bacteria and serve as a source of food for small ocean animals like krill.
Several years ago, the lab Nicole King, a professor of molecular and cell biology at the University of California, Berkeley, and Howard Hughes Medical Institute investigator, discovered that certain bacteria make these one-celled choanoflagellates a. The discovery may help reveal how humans and other animals evolved from single-celled organisms over the last million years.
In this case, the bioluminescent marine bacterium Vibrio fischeri triggers the choanoflagellate Salpingoeca rosetta to swarm and mate.
Mating is sometimes a response to a changing environment. Mating among choanoflagellates has been a mystery—even whether choanos engaged in sexual reproduction—until her team discovered in that starvation could trigger mating, although only a small percentage of cells would mate.
The new study shows that Vibrio bacteria elicit a much more rapid response, with large percentages of cells mating within hours.
The new discovery suggests that other creatures, including some that have been difficult to study in the lab because they fail to mate, may need a little bacterial aphrodisiac to get it on. They showed that EroS is a chondroitinase, an enzyme that degrades a specific type of sulfated molecule found in the extracellular matrix of S.
They also found that if this enzymatic function was inhibited, swarming did not occur, and that chondroitinases from other aquatic bacteria reproduced the aphrodisiacal effects. The National Institutes of Health funded the work, which appears in the journal Cell. Science Health Culture Environment.