Migratory adult sea lampreys locate spawning streams by using a pheromone released by stream-resident conspecific larvae. It was recently reported that this pheromone is comprised of a mixture of three sulfated steroids: petromyzonamine disulfate (PADS), petromyzosterol disulfate (PSDS), and petromyzonol sulfate (PS). This manuscript reports in-depth details of pheromone isolation and provides new information on the olfactory potency of PADS and PSDS and the behavioral activity of synthesized PADS. Isolation was accomplished using bioassay-guided fractionation which included liquid chromatography-mass spectrometry, electro-olfactogram recording (EOG), and behavioral assays. Both highly purified and synthesized PADS stimulated the olfactory system of adult lamprey and were attractive at concentrations of 10-13 M. PSDS also had olfactory activity at 10-13 M. Cross-adaptation studies with EOG recording demonstrated that PADS, PSDS, and PS are detected by independent olfactory receptor sites. Finally, the mixture of all three components was as attractive as larval water to adult sea lampreys in laboratory mazes. It is believed that these steroids are the principal components of the pheromone.
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Acknowledgments We thank the staff of the Hammond Bay Biological Station (U.S. Geological Survey) who provided assistance, access to their facilities, and larval lampreys. Adult lampreys were supplied by the Marquette Biological Station (US Fish and Wildlife Service) and the Department of Fisheries and Oceans (Canada). We also thank Lance Vrieze, Sean Sisler, Melanie Burton, Chad Nordstrom, Elizabeth Fine, and Daniel Kurkeiwicz for assistance with behavioral studies. Tom Krick and Leeann Higgins of the Mass Spectrometry Consortium for the Life Sciences at the University of Minnesota provided assistance and access to their facility. We are grateful to Tom Hoye and Vadims Dvornikovs for advice, insight, synthesized PADS, and reviewing early versions of this manuscript. Chris Jeffrey and Andy Graves also reviewed earlier versions of this manuscript. Funding was provided by the Great Lakes Fishery Commission and the Minnesota Agricultural Experiment Station.
Copyright 2009 Elsevier B.V., All rights reserved.
- Bioassay-guided fractionation
- Migratory pheromone
- Petromyzonamine disulfate
- Petromyzonol sulfate
- Petromyzosterol disulfate
- Sea lamprey