Genome sequence of a valued traditional Chinese medicine Cordyceps militaris
There are about one thousand fungal species that can infect and kill insects. The species like Metarhizium spp. And Beauveria spp. Have been developed as promising insect biocontrol agents while the Cordyceps species like C. militaris and C. sinensis (Syn. Ophiocordyceps sinensis) are traditional Chinese medicines used in eastern countries for hundreds of years. The evolution of fungal entomopathogenicity, sexuality and the genes involved in biosynthesis of bioactive metabolites of Cordyceps spp. Are still poorly understood.
Prof. Chengshu Wang (http://sourcedb.cas.cn/sourcedb_sibs_cas/yw/rck/200906/t20090629_1856154.html
) at the Institute of Plant and Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Science, and co-workers have recently sequenced the genome of the model species of C. militaris and found 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. Consistent with its long track record of safe usage as a medicine, the Cordyceps genome does not contain genes for known human mycotoxins. They also established that C. militaris is sexually heterothallic but, very unusually, fruiting can occur without an opposite mating-type partner.
High throughput transcriptional profiling indicated that the fruiting of C. militaris involved induction of the Zn2Cys6-type transcription factors and MAPK pathway; unlike other fungi, however, the PKA pathway is not activated.
Their study offered a better understanding of Cordyceps biology and will facilitate the exploitation of medicinal compounds produced by the fungus.
This work have been published as a cover study on the journal of Genome Biology. 2011, 12(11): R116. (