1 1 Symposium Chemosensory Receptors Satellite DEVELOPMENT ...

313 Poster Chemosensory Molecular Genetics andVNO/PheromoneEVIDENCE FOR A PERIRECEPTOR ROLE FOR HARDERIANGLAND SECRETIONS IN GARTER SNAKES: DELIVERY OFPHEROMONE MOLECULES TO THE VOMERONASALORGANMason R.T. 1 , Wang D.T. 2 , Chen P. 2 , Halpern M. 3 1 Zoology, OregonState Univ, Corvallis, OR; 2 Biochemistry, SUNY Health ScienceCenter, Brooklyn, Brooklyn, NY; 3 Anatomy & Cell Biology, SUNYHealth Science Center, Brooklyn, Brooklyn, NYOne of the few vertebrate pheromones that have been isolated,purified and characterized is the sex pheromone of the female red-sidedgarter snake (Thamnophis sirtalis parietalis). This pheromone, a blendof 13 long-chain (C29-C37) saturated and monounsaturated methylketones, is expressed during the mating season and responded to bymales with stereotyped courtship behaviors including chin-rubbing,rapid tongue-flicks and caudocephalic body undulations. Due to thehigh molecular weight and the aliphatic chain length, this nonpolarfemale sex pheromone is insoluble in aqueous solution. Perception ofthe pheromone is mediated by receptor neurons of the vomeronasalorgan (VNO). These receptor cells are bathed in a fluid originating inthe Harderian gland (HG). The question arose: How does this nonpolarlipophilic pheromone access VNO receptor cells? We found thathomogenates of HG were effective in solubilizing the pheromone,which allowed us to demonstrate that the pheromone incubated with HGhomogenate increased IP3 production in VN sensory epithelialhomogenates. Furthermore, HG removal in reproductively active malesresulted in a significant reduction in courtship behavior. Following thebreeding season, feeding Harderianectomized males were impaired inearthworm attack. These results indicate that HG secretions possesssolubilizing and/or pheromone binding properties that are critical fordelivery of chemosignals (pheromones and prey cues) to the VNO.314 Poster Chemosensory Molecular Genetics andVNO/PheromoneGONADOTROPIN RELEASING HORMONE INCREASESVOMERONASAL NEURON RESPONSE TO MALESALAMANDER PHEROMONEWirsig-Wiechmann C.R. 1 , Feldhoff R.C. 2 , Feldhoff P.W. 2 , Houck L. 31 Cell Biology, University of Oklahoma, Oklahoma City, OK;2 Biochemistry and Molecular Biology, University of Louisville,Louisville, KY; 3 Zoology, Oregon State University, Corvallis, ORElectophysiological studies have shown that gonadotropin releasinghormone (GnRH) influences chemosensory neurons responses to odors.In the present study we used agmatine uptake as a relative measure ofthe effects of GnRH on pheromone-induced neural activation ofvomeronasal neurons in Plethodon shermani salamanders. Whole malepheromone extract containing 3 millimolar agmatine with or without 10micromolar GnRH was applied to the nasolabial groove of femalesalamanders. Immunocytochemical procedures, using diaminobenzidineas the chromogen, were conducted to visualize and quantify relativelabeling density of activated vomeronasal neurons in 20 micron thicksections of vomeronasal organ. Tissue sections from each experimentalgroup were processed on the same slide to ensure identical labelingprocedures. Densitometry data were collected from individualvomeronasal neurons that showed clear labeling of the entire cell. Eachvalue was standardized by dividing the cell body density by backgrounddensity. Multiple density values from each of three specimens fromeach group were used to determine inter-group differences. Groupswere compared using Student´s T test. Vomeronasal neurons exposed topheromone and GnRH demonstrated higher density values (averagedensity = 1.79) than neurons exposed to pheromone alone (averagedensity = 1.64; t = -2.79, df = 226, p < 0.003). This result suggests thatGnRH increases the response of female vomeronasal neurons to malepheromone. Supported by National Science Foundation Grant IBN-0110666.315 Poster Chemosensory Molecular Genetics andVNO/PheromoneSYNTHESIZED MALE SEA LAMPREY PHEROMONESUMMONS CONSPECIFIC FEMALES TO TRAPSLi W. 1 , Johnson N. 1 , Yun S. 1 1 Fisheries and Wildlife, Michigan StateUniversity, East Lansing, MIThe sea lamprey (Petromyzon marinus) is an ecologically destructiveinvader of the Laurentian Great Lakes. Our previous studies indicatethat sexually mature male sea lampreys release through gills 7Ñ, 12Ñ,24-trihydroxy-5Ñ-cholan-3-one 24-sulfate (3kPZS), which inducesrobust and predictable upstream movement in ovulatory femaleconspecifics. This compound offers a possible system for developing apheromone-based sea lamprey control, even though vertebrate animalshave not been expected to "fly up" the concentration gradient ofpheromones like insects. In the present study, synthesized 3kPZS wasintroduced into a lamprey spawning stream where tagged ovulatoryfemales were acclimated and released. At subpicomolar concentrations,3kPZS lured more than 50% of females into traps. This compound waseffective in guiding females to the exact site of traps over 600 meters.Temperature fluctuation appeared to influence the trapping efficiency.We conclude 3kPZS can be developed into a potent pest control agent.This study was supported by the Great Lakes Fishery Commission andthe National Science Foundation.316 Poster Chemosensory Molecular Genetics andVNO/PheromoneREFLECTIONS AMONG ASIAN ELEPHANTS: CHIRALITYCOUNTSRasmussen L. 1 , Greenwood D.R. 2 1 Environmental & BiomolecularSystems, Oregon Health & Science University, Beaverton, OR; 2 Schoolof Biological Sciences, University of Auckland, Auckland, New ZealandThe two enantiomers or molecular mirror images of the maleelephant-temporalgland released pheromone, frontalin (1,5-dimethyl-6,8-dioxabicyclo[3.2.1]octane) are emitted in specific proportions,dependent on the male elephants age and phase of musth (Greenwood etal., Nature 438:1097-8, 2005). Musth and male maturation are linked,progressively culminating in overall sexual, social, physiological andphysical maturity, resulting in a lengthy annual period of musthcharacterized by heightened sexual activity and intensified aggression.We demonstrate that, compared with young males, older males show aconsistent, repeatable pattern of enantiomeric proportions duringindividual musth episodes and that behavioural reactions byconspecifics are more influenced by the ratio of enantiomers than totalfrontalin. In addition, frontalin enantiomers, as tightly stable molecules,can be traced as far as a source origin in the blood of musth elephantsand importantly, with their precursor are found in other mammaliantissues, including whales. This argues for a link to fundamentalmetabolism via the mevalonate shunt, perhaps influenced by steroidhormones. Such is one of the foci of our continuing investigations.Supported by National Science Foundation.79