来自加州理工学院,霍德华休斯医学院的研究人员首次发现了费洛蒙调控攻击性的确实系统,并解开了一个进化保守性神经生物学机制的谜团。这一研究成果公布在Nature杂志上。
费洛蒙(Pheromone,也有翻译为弗洛蒙、费洛蒙,佛罗蒙,或者香偶素),是指一种由动物体分泌出来且具有挥发性的化学物质,它可使同种动物在不同个体之间,透过嗅觉的作用而传递讯息,产生行为或生理上的变化 (Karlson and Luscher.1959) 。这种化学物质由外分泌腺 (exocrine gland)所分泌,分子很小,可随风飘逸再藉空气流动快速的传播到各处去。弗洛蒙它是动物界包括人类、哺乳动物、昆虫(蜜蜂、蚂蚁、飞蛾)等同物种之间相互沟通,并发出求偶、警戒、社交、合作等讯号的讯息分子。
之前的研究发现许多动物物种中费洛蒙都能调控攻击性(aggression),但是目前还没有发现这种攻击性费洛蒙,费洛蒙受体和相应的感官神经细胞系统。
在这篇文章中,研究人员发现了一种雄性易挥发的信息素:11-cis-vaccenyl acetate(cVA)能促进研黄果蝇(Drosophila melanogaster)中的雄性攻击性。这种攻击性的提升需要嗅觉感应神经元(olfactory sensory neurons,OSNs)以及其表达受体Or67d。
Or67d基因的定向突变的一个实验证实了cVA对雌性和雄性的不同作用,在两个性别中cVA都发挥作用,但在雄性中它抑制交配行为,在雌性中它鼓励交配行为。缺失Or67d的突变雄性错误地向其他雄性求偶,而有同样突变的的雌性对求偶的雄性却变得不是很接受。
这些研究数据表明,cVA也许通过调控攻击性扮演着负调控雄性个体密度的角色,这一遗传机制的发现打开了这种进化保守性的神经生物学机制。
近期另外一项研究通过费洛蒙解开了果蝇的一个谜团: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,这到底是什么原因呢?
研究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。(生物谷Bioon.com)
生物谷推荐原始出处:
Nature 6 December 2009 | doi:10.1038/nature08678
Identification of an aggression-promoting pheromone and its receptor neurons in Drosophila
Liming Wang1 & David J. Anderson1,2
1 Division of Biology 216-76,
2 Howard Hughes Medical Institute, California Institute of Technology, 1200 East California Boulevard, Pasadena, California 91125, USA
Correspondence to: Liming Wang1David J. Anderson1,2 Correspondence and requests for materials should be addressed to D.J.A. or L.W.
Aggression is regulated by pheromones in many animal species1, 2, 3. However, in no system have aggression pheromones, their cognate receptors and corresponding sensory neurons been identified. Here we show that 11-cis-vaccenyl acetate (cVA), a male-specific volatile pheromone, robustly promotes male–male aggression in the vinegar fly Drosophila melanogaster. The aggression-promoting effect of synthetic cVA requires olfactory sensory neurons (OSNs) expressing the receptor Or67d4, 5, 6, as well as the receptor itself. Activation of Or67d-expressing OSNs, either by genetic manipulation of their excitability or by exposure to male pheromones in the absence of other classes of OSNs, is sufficient to promote aggression. High densities of male flies can promote aggression by the release of volatile cVA. In turn, cVA-promoted aggression can promote male fly dispersal from a food resource, in a manner dependent on Or67d-expressing OSNs. These data indicate that cVA may mediate negative-feedback control of male population density, through its effect on aggression. Identification of a pheromone–OSN pair controlling aggression in a genetic organism opens the way to unravelling the neurobiology of this evolutionarily conserved behaviour.