Vogt R G, Riddiford L M
Department of Zoology, University of Washington, Seattle, Washington 98195, USA.
Nature. 1981;293(5828):161-3. doi: 10.1038/293161a0.
The antennae of male silk moths are extremely sensitive to the female sex pheromone such that a male moth can find a female up to 4.5 km away. This remarkable sensitivity is due to both the morphological and biochemical design of these antennae. Along the branches of the plumose antennae are the sensilla trichodea, each consisting of a hollow cuticular hair containing two unbranched dendrites bathed in a fluid, the receptor lymph ,3. The dendrites and receptor lymph are isolated from the haemolymph by a barrier of epidermal cells which secreted the cuticular hair. Pheromone molecules are thought to diffuse down 100 A-wide pore tubules through the cuticular wall and across the receptor lymph space to receptors located in the dendritic membrane. To prevent the accumulation of residual stimulant and hence sensory adaptation, the pheromone molecules are subsequently inactivated in an apparent two-step process of rapid 'early inactivation' followed by much slower enzymatic degradation. The biochemistry involved in this sequence of events is largely unknown. We report here the identification of three proteins which interact with the pheromone of the wild silk moth Antheraea polyphemus: a pheromone-binding protein and a pheromone-degrading esterase, both uniquely located in the pheromone-sensitive sensilla; and a second esterase common to all cuticular tissues except the sensilla.
雄蚕蛾的触角对雌蛾性信息素极为敏感，以至于雄蛾能够找到4.5公里外的雌蛾。这种非凡的敏感性源于这些触角的形态和生化设计。在羽状触角的分支上是毛形感器，每个毛形感器由一根中空的表皮毛组成，其中包含两根未分支的树突，浸泡在一种液体——受体淋巴液中。树突和受体淋巴液通过分泌表皮毛的表皮细胞屏障与血淋巴隔离。信息素分子被认为通过100埃宽的孔道扩散穿过角质层壁，穿过受体淋巴液空间，到达位于树突膜上的受体。为了防止残留刺激物的积累从而避免感觉适应，信息素分子随后在一个明显的两步过程中失活，第一步是快速的“早期失活”，随后是慢得多的酶促降解。这一系列事件所涉及的生物化学过程在很大程度上尚不清楚。我们在此报告鉴定出三种与野生蚕蛾多音大蚕蛾的信息素相互作用的蛋白质：一种信息素结合蛋白和一种信息素降解酯酶，二者都独特地位于对信息素敏感的感器中；以及一种除感器外所有表皮组织都有的第二种酯酶。
