Novel, species-typical esters from preputial glands of sympatric voles,Microtus montanus andM. pennsylvanicus.

Olfactory signals may facilitate species recognition between the sympatric voles,Microtus montanus andM. pennsylvanicus. In an effort to isolate and identify compounds that might contribute to such a chemical communication system, the preputial glands of those voles have been examined. Morphological examinations show both vole species possess preputial glands; however, the glands ofM. montanus are much larger than those ofM. pennsylvanicus. Gas Chromatographie analysis revealed that the preputial glands ofM. montanus contain a series of species-typical lipids that are not found inM. pennsylvanicus. Using gas chromatography-mass spectrometry and nuclear magnetic resonance spectrometry, the species-typical lipids were identified as esters of branched, saturated, and unsaturated C5 and C4 alcohols and straight-chain C16, and "iso" branched C17 fatty acids. This is the first description of such esters from mammalian tissues. The results are discussed relative to the possibility that the species-typical esters act as species recognition cues for the sympatric voles.