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和蛇中毒系统的早期演变
Bryan G Fry1, Nicolas Vidal, Janette A Norman
1Australian Venom Research Unit, Level 8, School of Medicine, University of Melbourne, Parkville, Victoria 3010, Australia. bgf@unimelb.edu.au
Nature
|November 18, 2005
概括
这项研究揭示了监视和伊瓜尼亚人中的毒毒素,表明和蛇中毒系统的单一早期起源. 这一发现扩大了我们对爬行动物进化和潜在的生物医学应用的理解.
科学领域:
- 进化生物学 进化生物学
- 类学 类学 类学 类学
- 生物化学 生物化学
背景情况:
- 以前,毒液传递系统仅在先进的蛇和两个物种 (helodermatids) 中是已知的.
- 毒液的进化被认为是先进蛇辐射的关键因素.
- 人们认为的毒液系统是有限的,并且已经独立于蛇的进化.
研究的目的:
- 为了调查其他系中毒素的存在,特别监测和伊瓜尼亚.
- 确定状爬行动物中毒系统的进化起源和关系.
- 探索新型毒毒素的潜在生物医学应用.
主要方法:
- 从口腔腺体构建互补DNA库.
- 对腺体转录的遗传学分析,以确定共享的毒素.
- 从蕾丝监视器 (Varanus varius) 和胡子龙 (Pogona barbata) 的毒素成分的毒理学分析.
主要成果:
- 在监视和伊瓜尼亚中发现了毒毒素,扩大了已知的有毒的多样性.
- 和蛇之间共有9种毒素类型,支持单一的进化起源.
- 和蛇毒系统形成一个单一的类,表明一个共同的,早期的祖先.
- 来自Varanus varius的毒素成分对血压和凝固有强烈的影响.
- 祖先的毒腺存在于伊瓜尼亚,而先进的蛇和 anguimorph 显示衍生系统.
结论:
- 状爬行动物的毒液输送系统起源于他们共同的祖先中的一个单一的早期事件.
- 这一发现挑战了以前关于和蛇毒的独立进化的假设.
- 已识别的毒毒素代表了生物医学研究和药物发现的新资源.
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