Whittington Camilla M, Belov Katherine
School of Biological Sciences, The University of Sydney, Camperdown, NSW 2006, Australia.
Faculty of Veterinary Science, The University of Sydney, Camperdown, NSW 2006, Australia.
Toxins (Basel). 2014 Apr 2;6(4):1260-73. doi: 10.3390/toxins6041260.
The monotremes (platypuses and echidnas) represent one of only four extant venomous mammalian lineages. Until recently, monotreme venom was poorly understood. However, the availability of the platypus genome and increasingly sophisticated genomic tools has allowed us to characterize platypus toxins, and provides a means of reconstructing the evolutionary history of monotreme venom. Here we review the physiology of platypus and echidna crural (venom) systems as well as pharmacological and genomic studies of monotreme toxins. Further, we synthesize current ideas about the evolution of the venom system, which in the platypus is likely to have been retained from a venomous ancestor, whilst being lost in the echidnas. We also outline several research directions and outstanding questions that would be productive to address in future research. An improved characterization of mammalian venoms will not only yield new toxins with potential therapeutic uses, but will also aid in our understanding of the way that this unusual trait evolves.
单孔目动物（鸭嘴兽和针鼹）是现存仅有的四个有毒哺乳动物谱系之一。直到最近，人们对单孔目动物的毒液还知之甚少。然而，鸭嘴兽基因组的可得性以及日益复杂的基因组工具使我们能够对鸭嘴兽毒素进行表征，并提供了一种重建单孔目动物毒液进化史的方法。在这里，我们回顾了鸭嘴兽和针鼹腿部（毒液）系统的生理学以及单孔目动物毒素的药理学和基因组学研究。此外，我们综合了目前关于毒液系统进化的观点，在鸭嘴兽中，毒液系统可能是从有毒的祖先那里保留下来的，而在针鼹中则已经消失。我们还概述了几个研究方向和悬而未决的问题，这些问题在未来的研究中进行探讨将富有成效。对哺乳动物毒液的更好表征不仅会产生具有潜在治疗用途的新毒素，还将有助于我们理解这种不寻常特征的进化方式。
