BEHAVIOURAL AND MOLECULAR BIOLOGICAL ASPECTS 0F (Z)-7-DODECENYLACETATE AS A SEX PHEROMONE IN ASIAN ELEPHANTS

L.E.L. Rasmussen¹, W.L. Roelofs², A. Zhang², J. Lazar³, L Feng³ and G.D. Prestwich^3
1Dept. of Chemistry, Oregon Graduate Institute, Beaverton,OR 97006.
²Dept. of Entomology, Cornell University, Geneva, NY 14456.
³Dept. of Medicinal Chemistry, University of Utah, SaltLake City, UT 84112.

(Z)-7-dodecenyl acetate (Z7-12:Ac) has recently been demonstrated tobe an active pheromone in Asian elephants, Elephas maximus. Assayswith solitary male Asian elephants demonstrated a high frequency of non-habituatingchemosensory responses, especially flehmen responses, often followed bymating behaviour, toward female preovulatory urine and toward authentic,synthetic Z7-12:Ac. Field test in Myanmar demonstrated significant inter-malevariability in response, with social context influencing responsivity.Not only did some males exhibit higher responses than the solitary malesin USA, but selected, less dominant males demonstrated avoidance. In thefemale urine Z7-12:Ac appears in increasing concentrations from early follicularto preovulatory periods. Bioassays of urinary G-25 Sephadex chromatographicfractions as well as the differential response to synthetic Z7-12:Ac inseveral presentation media- distilled water, acetate buffer and controlurine- suggest a protein component is involved for full bioactivity. Inour beginning efforts to elucidate a protein component, we have synthesiseda photoaffinity analogue of the female pheromone. Bioassays of this analogue,by presentation in water or anestrous urine, elicited respectively similar,although reduced bioresponses from solitary male elephants. The tritiatedZ7-12:Dza will be employed to photoaffinity label ligand-specific bindingproteins and to follow the isolation of these odorant binding proteinsfrom female urine, male trunk mucus and male vomeronasal tissue.