天然冬虫夏草多菌共存生物体分子异质性的检验与讨论

Genetic Heterogeneity of Natural Cordyceps sinensis with Co-existence of Multiple Fungi

中药冬虫夏草数百年来用于滋补保健、疾病防治和病后康复,但有关冬虫夏草菌的学术争议一直没有停止。中国被毛孢是冬虫夏草菌的无性世代学说较为流行,然而学界尚未获得证实这一学说的直接证据。部分间接证据来自于分子系统学微观和宏观研究。该文回顾了冬虫夏草分子系统学文献,讨论了微观研究和宏观研究的实验方法、数据分析方法及其结果。冬虫夏草分子生物学微观研究不断获得新证据,证明天然冬虫夏草基因组DNA的多元异质性,揭示冬虫夏草中含有的多种真菌和多种突变基因型冬虫夏草菌,证明冬虫夏草是多种真菌与蝙蝠蛾幼虫尸体构成的复杂的菌虫物种复合体。随着冬虫夏草的成熟,在僵虫体和子座中多种菌物的差异存在巨大的、非同步的动态变化。宏观分子系统学研究的丰度加权算法揭示在僵虫体、子座和子囊果中分子标记多态性的高度差异及其在冬虫夏草成熟过程中的动态变化。这些分子系统学研究结果支持冬虫夏草是"一个统一微生态系统"的学说。

Natural Cordyceps sinensis is a precious traditional Chinese herb and has been used as a folk medicine for hundreds of years for promoting health, combating diseases and facilitating post-disease recovery. However, the debate on the anamorph-teleomorph connection for Ophiocordyceps sinensis fungus has been undergoing for decades. Direct evidence is still lacking for the hypothesis that Hirsutella sinensis is the sole anamorph of O. sinensis. Some indirect evidence was derived from molecular systematics studies using either microcosmic or macrocosmic techniques. This paper reviewes the C. sinensis molecular systematics publications and discusses their experimental designs and methodologies, data analysis methods and the results. More and more new data from microcosmic molecular biology studies demonstrated the multiple genetic heterogeneity of the C. sinensis genomic DNA pool, indicating that natural C. sinensis contains multiple fungi and multiple genotypes of O. sinensis, forming a natural fungi-insect complex. The fungi that differentially exist in the caterpillar body, stroma and ascocarps of C. sinensis undergo dynamic, asynchronous alterations during C. sinensis maturation. Macrocosmic analyses with using density-weighted algorithms demonstrated the dramatic differences in the integral molecular marker polymorphism in the different compartments of C. sinensis, and the dynamic alterations of the molecular marker polymorphism during C. sinensis maturation. All these results from molecular systematics studies supported the hypothesis of an integrated micro-ecosystem for natural C. sinensis.