Dumbacher John P, Wako Avit, Derrickson Scott R, Samuelson Allan, Spande Thomas F, Daly John W
Smithsonian Conservation Research Center, Front Royal, VA 22630, USA.
Proc Natl Acad Sci U S A. 2004 Nov 9;101(45):15857-60. doi: 10.1073/pnas.0407197101. Epub 2004 Nov 1.
Batrachotoxins are neurotoxic steroidal alkaloids first isolated from a Colombian poison-dart frog and later found in certain passerine birds of New Guinea. Neither vertebrate group is thought to produce the toxins de novo, but instead they likely sequester them from dietary sources. Here we describe the presence of high levels of batrachotoxins in a little-studied group of beetles, genus Choresine (family Melyridae). These small beetles and their high toxin concentrations suggest that they might provide a toxin source for the New Guinea birds. Stomach content analyses of Pitohui birds revealed Choresine beetles in the diet, as well as numerous other small beetles and arthropods. The family Melyridae is cosmopolitan, and relatives in Colombian rain forests of South America could be the source of the batrachotoxins found in the highly toxic Phyllobates frogs of that region.
蟾毒素是一类神经毒性甾体生物碱，最初是从哥伦比亚箭毒蛙中分离出来的，后来在新几内亚的某些雀形目鸟类中也有发现。这两类脊椎动物都不被认为能从头合成这些毒素，而是可能从食物来源中摄取它们。在此，我们描述了在一个研究较少的甲虫类群——Choresine属（拟花萤科）中存在高含量的蟾毒素。这些小甲虫及其高毒素浓度表明，它们可能为新几内亚鸟类提供了毒素来源。对黑头林鵙鹟的胃内容物分析显示，其食物中有Choresine甲虫，以及许多其他小型甲虫和节肢动物。拟花萤科分布于世界各地，南美洲哥伦比亚雨林中的近亲可能是该地区剧毒叶毒蛙体内蟾毒素的来源。
