生物学家发现，在配对之前雌性果蝇对雄性果蝇有巨大魅力，可一旦它们结合后，雌果蝇就会失去对其他雄果蝇的吸引力，其原因一直不明。一个德美联合研究小组最近发现，是一种性信息素的作用导致了这一奇特现象。
德国明斯特大学和美国哈佛大学的研究人员在美国《当代生物学》网站上报告说，昆虫利用嗅觉或腿部分布的接触感受器，去感应其他昆虫体表附着的各种特殊碳氢化合物来进行信息交流，其中引起性冲动的化合物被称为性信息素。
上述两家高校的科研人员利用飞行时间质谱仪技术，发现一种名为CH503的碳氢化合物会在雄果蝇体表的一个专区密集分布，在与雌果蝇结合时，这种性信息素会传播到雌果蝇身上并附着10天以上。
研究人员对未与异性结合的雌果蝇人工喷洒CH503，结果它们随即失去了对雄果蝇的吸引力，这说明性信息素CH503会抑制雄果蝇的配对欲望。
参与这项研究的科研人员推测，避免连续配对对果蝇种群有好处。首先，两性繁殖所必需的遗传物质不会被其他雄果蝇破坏，雌果蝇也会因得不到其他雄果蝇的青睐而一心一意地选址产卵。（生物谷Bioon.com）
生物谷推荐原始出处：
Current Biology, 16 July 2009 doi:10.1016/j.cub.2009.06.037
A New Male Sex Pheromone and Novel Cuticular Cues for Chemical Communication in Drosophila
Joanne Y. Yew1,2,5,,,Klaus Dreisewerd2,5,Heinrich Luftmann3,Johannes Müthing4,Gottfried Pohlentz2andEdward A. Kravitz1
1 Department of Neurobiology, Harvard Medical School, 220 Longwood Avenue, Boston, MA 02115, USA
2 Institute of Medical Physics and Biophysics, University of Münster, 48149 Münster, Germany
3 Institute of Organic Chemistry, University of Münster, 48149 Münster, Germany
4 Institute of Hygiene, University of Münster, 48149 Münster, Germany
In many insect species, cuticular hydrocarbons serve as pheromones that can mediate complex social behaviors. In Drosophila melanogaster, several hydrocarbons including the male sex pheromone 11-cis-vaccenyl acetate (cVA) and female-specific 7,11-dienes influence courtship behavior and can function as cues for short-term memory associated with the mating experience. Behavioral and physiological studies suggest that other unidentified chemical communication cues are likely to exist. To more fully characterize the hydrocarbon profile of the D. melanogaster cuticle, we applied direct ultraviolet laser desorption/ionization orthogonal time-of-flight mass spectrometry (UV-LDI-o-TOF MS) and analyzed the surface of intact fruit flies at a spatial resolution of approximately 200 m.We report the chemical and spatial characterization of 28 species of cuticular hydrocarbons, including a new major class of oxygen-containing compounds. Via UV-LDI MS, pheromones previously shown to be expressed exclusively by one sex, e.g., cVA, 7,11-heptacosadiene, and 7,11-nonacosadiene, appear to be found on both male and female flies. In males, cVA colocalizes at the tip of the ejaculatory bulb with a second acetylated hydrocarbon named CH503. We describe the chemical structure of CH503 as 3-O-acetyl-1,3-dihydroxy-octacosa-11,19-diene and demonstrate a behavioral role for this compound as a long-lived inhibitor of male courtship. Like cVA, CH503 is transferred from males to females during mating. Unlike cVA, CH503 remains on the surface of females for at least 10 days.Oxygenated hydrocarbons comprise a major previously undescribed class of compounds on the Drosophila cuticular surface. A newly discovered long-chain acetate, CH503, serves as a mediator of courtship-related chemical communication.
