中国科学院动物研究所等单位的科学家最近从模式动物——小鼠的特化气味腺(包皮腺和阴蒂腺)中发现两个新的半挥发性信息素分子(16碳醇和16醇乙酸脂)，并证明它们具有剂量依赖的、双相性吸引效应。此发现是该组研究人员在他们去年推定的多个小鼠性信息素成分(Chemical Senses 32:293-303)的基础上，进一步对其功能测定的结果。

    这两个过去未被报道的主要气味成分为雌雄共享，但在雄鼠中的含量显著高于雌性，而且对睾丸有依赖性；将合成的16碳醇和16醇乙酸脂按分泌到雄鼠尿液的生理浓度(高浓度)加入阉割雄鼠的尿液，对雌鼠产生吸引作用，说明它们是雄性信息素；同时，切除犁鼻器(VNO)的雌鼠对这两个成分的偏好消失，这种VNO依赖性的性吸引作用，进一步说明它们是小鼠的雄性信息素；但是，当这两个成分同时按生理水平加入阉割雄鼠的尿液时，才能表现出显著的性吸引作用；如果只用其中之一则需要高出生理浓度很多，才能有性吸引效应，说明这两个成分是有增效作用(synergism)的雄性信息素成分。出乎预料的是，这两个成分以接近雌鼠尿液中的生理含量(低浓度)，加入阉割雄鼠尿液，则对雄鼠产生性吸引作用，说明这两个雌雄鼠气味腺共有的成分具有剂量依赖的反向效应的性吸引作用。用其水溶液进行测试也表现出同样的效果。最近的实验又证明雄鼠对这两个成分的反应也是VNO依赖的。另外，北京生命科学研究所罗敏敏实验室的脑神经反应测试也说明它们可以激活雌性小鼠副嗅球、主嗅球、杏仁体和下丘脑的c-Fos反应，再次从神经生物学角度确认了它们的信息素身份。

    小鼠信息素的化学研究已有30多年，国外报到了8个挥发性信息素成分。该研究在小鼠的信息素成分谱中添加了两个主要成分，也首次阐明雌小鼠吸引雄小鼠的信息素，并阐明了哺乳动物利用雌雄共享气味成分的剂量差异来传递性别信息的编码特点。另外，小鼠和全球分布最广的害鼠－小家鼠为同种，这两个低挥发性的双相信息素可能在鼠害控制中有一定的应用潜力。

    主要成果于7月9日在国际行为神经科学学会(IBNS)官方杂志——爱思唯尔期刊《生理与行为》（Physiology and Behaviour）在线发表。三个审稿人认为，该论文在坚实的GC-MS分析基础上，对两个新的信息素成分的特性进行了扼要探索，是原创性的，对增加哺乳动物气味及性别和个体识别的知识做出了贡献。

    该论文作者为张健旭、刘莹娟、张进华和孙立新，得到国家基金委面上项目，科学院创新项目和科技部攻关项目的资助。

原始出处：

Physiology and Behaviour，doi:10.1016/j.physbeh.2008.07.002，Jian-Xu Zhang, Ying-Juan Liu, Jin-Hua Zhang and Lixing Sun

Dual role of preputial gland secretion and its major components in sex recognition of mice

Jian-Xu Zhanga, Ying-Juan Liua, Jin-Hua Zhanga and Lixing Sunc

aState Key Laboratory of Integrated Management of Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Datun Road, Beijing 100101, China bSchool of Biological Sciences, Beijing Forestry University, Beijing 100083, China cDepartment of Biological Sciences, Central Washington University, Ellensburg WA98926-7537, USA

Abstract

This study was aimed at validating the sexual attractiveness of hexadecanol and hexadecyl acetate, two putative pheromone compounds, from preputial gland secretion of mice. These two compounds have been reported to be among the major components of preputial gland secretion in both sexes but higher in quantity in males than females. In this study, we show that castration suppressed the production of the two compounds, further suggesting their association with maleness. Adding preputial gland secretion and the synthetic analogs of the two compounds to castrated male urine at their physiological levels in intact males increased the attractiveness of castrated male urine to female mice, showing that the two compounds were indeed male pheromones. Furthermore, their sexual attractiveness disappeared upon removing the vomeronasal organs (VNOs) from female recipients. Replenishing castrated male urine with preputial gland secretion and the two compounds at their physiological levels in females increased the attractiveness of castrated male urine to males. Such a reversal of sexual attractiveness for hexadecanol and hexadecyl acetate suggests that they had opposing dual effects in sexual attractiveness in a dosage-dependent manner.