近日,，中科院上海生科院植生生態(tài)所王成樹課題組關(guān)于蛹蟲草基因組的研究取得進展，相關(guān)文章發(fā)表在Genome Biology上，為深入研究蟲草活性成分代謝途徑及其有性生殖的分子調(diào)控機理等奠定了良好的基礎(chǔ),。
能夠感染殺蟲的真菌種類達1000多種,，主要為子囊菌。以綠僵菌和白僵菌等為代表的昆蟲病原真菌已被開發(fā)為環(huán)境友好的真菌殺蟲劑,；以冬蟲夏草和蛹蟲草（又稱北蟲草、北冬蟲夏草）等為代表的昆蟲病原真菌具有良好的醫(yī)藥保健功能,。進化基因組分析表明蛹蟲草的出現(xiàn)較綠僵菌早約1.3億年,，各自獨立進化而具有殺蟲特性，但表現(xiàn)出協(xié)同進化的特點：與其他真菌相比,，蛋白酶和幾丁質(zhì)酶等用于昆蟲體壁降解的蛋白質(zhì)家族表現(xiàn)出明顯的擴張現(xiàn)象,。基因組分析表明,，蛹蟲草基因組大約有16%的編碼基因參與真菌—昆蟲的相互作用,，不存在編碼對于人類有害的已知真菌毒素。首次表明蛹蟲草有性生殖類型為異宗配合,，但單交配型菌株能夠結(jié)實,。此外，與其他真菌不同,，其子實體發(fā)育主要受MAPK信號途徑調(diào)控,，而非MAPK和PKA共同調(diào)控。
這是該課題組完成綠僵菌比較基因組研究后(PLoS Genetics, 2011),，關(guān)于昆蟲真菌基因組研究的又一成果,。該項研究獲得了創(chuàng)新2020、上海市科委及973等項目支持,。（生物谷Bioon.com）
doi:10.1186/gb-2011-12-11-r116
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Genome sequence of the insect pathogenic fungus Cordyceps militaris, a valued traditional Chinese medicine
Peng Zheng, Yongliang Xia, Guohua Xiao, Chenghui Xiong, Xiao Hu, Siwei Zhang, Huajun Zheng, Yin Huang, Yan Zhou, Shengyue Wang, Guo-Ping Zhao, Xingzhong Liu, Raymond J St Leger and Chengshu Wang
Species in the ascomycete fungal genus Cordyceps have been proposed to be the teleomorphs of Metarhizium species. The latter have been widely used as insect biocontrol agents. Cordyceps species are highly prized for use in traditional Chinese medicines, but the genes responsible for biosynthesis of bioactive components, insect pathogenicity and the control of sexuality and fruiting have not been determined. Here, we report the genome sequence of the type species C. militaris. Phylogenomic analysis suggests that different species in the Cordyceps/Metarhizium genera have evolved into insect pathogens independently of each other, and that their similar large secretomes and gene family expansions are due to convergent evolution. However, relative to other fungi including Metarhizium spp., many protein families are reduced in C. militaris, which suggests a more restricted ecology. Consistent with its long track record of safe usage as a medicine, the Cordyceps genome does not contain genes for known human mycotoxins. We establish that C. militaris is sexually heterothallic but, very unusually, fruiting can occur without an opposite mating-type partner. Transcriptional profiling indicates that fruiting involves induction of the Zn2Cys6-type transcription factors and MAPK pathway; unlike other fungi, however, the PKA pathway is not activated.
