Phyletic Evolution of Ophiocordyceps sinensis through Interkingdom Host Colonization between Plants and Insects

Ophiocordyceps sinensis, an entomogenous fungus parasitic in the larvae of ghost moths (Lepidoptera), has always been used as one of the most valued Traditional Chinese Medicines throughout the Orient World. However, O. sinensis fails to be artificially cultivated so far, because its occurrence and developmental mechanisms are crucial but almost completely unknown. In this study, the genetic marker mitochondrial small subunit (mtSSU) gene was cloned and identified by PCR and bioinformatic tools, and then the phylogenetic relationship between O. sinensis and related species was established based on mtSSU sequences with Maximum-Parsimony method. This phylogenetic project was reconstructed to show the evolution of host specificity and the process of interkingdom host jumping of O. sinensis, which revealed a natural outcome of co-evolution among this fungus, plants and Thitarodes insects. Therefore, this study will contribute to promote our understanding for life history and occurrence mechanism of O. sinensis.