TY - JOUR T1 - An aphrodisiac produced by <em>Vibrio fischeri</em> stimulates mating in the closest living relatives of animals JF - bioRxiv DO - 10.1101/139022 SP - 139022 AU - Arielle Woznica AU - Joseph P Gerdt AU - Ryan E. Hulett AU - Jon Clardy AU - Nicole King Y1 - 2017/01/01 UR - http://biorxiv.org/content/early/2017/05/17/139022.abstract N2 - 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. ER -