An aphrodisiac produced byVibrio fischeristimulates mating in the closest living relatives of animals

Abstract

We serendipitously discovered that the marine bacterium Vibrio fischeri induces sexual reproduction in one of the closest living relatives of animals, the choanoflagellate Salpingoeca rosetta. Although bacteria influence everything from nutrition and metabolism to cell biology and development in eukaryotes, bacterial regulation of eukaryotic mating was unexpected. Here we show that a single V. fischeri protein, the previously uncharacterized EroS, fully recapitulates the aphrodisiac activity of live V.fischeri. EroS is a chondroitin lyase; although its substrate, chondroitin sulfate, was previously thought to be an animal synapomorphy, we demonstrate that S. rosetta produces chondroitin sulfate and thus extend the ancestry of this important glycosaminoglycan to the premetazoan era. Finally, we show that V. fischeri, purified EroS, and other bacterial chondroitin lyases induce S. rosetta mating at environmentally-relevant concentrations suggesting that bacterially-produced aphrodisiacs likely regulate choanoflagellate mating in nature.

The origin of animal multicellularity and cell differentiation

“…The few exceptions represent an infrequently observed type of aggregative multicellularity, sexual agglutination, that has been reported in yeasts(Wickerham 1958), choanoflagellates(Woznica et al 2017) and Chlamydomonas(Bergman et al 1975). Like other cases of aggregation, it results in transient multicellular forms without coordinated motility, feeding or proliferation, and which dissociate after karyogamy has been accomplished.…”