Changes in RAPD molecular marker polymorphism during Cordyceps sinensis maturation

Abstract

Cordyceps sinensis (Cs) is a precious traditional Chinese herb, and is widely used for a variety of therapeutic purposes. With use of mycology and molecular biology approaches, scientists have identified >;30 genera of fungi and at least 6 genotypes of Ophiocordyceps sinensis from wild Cs. We reported maturational changes in chemical components, differential expression and functionality of Hirsutella sinensis (Hs) in Cs. We used a fuzzy molecular technique, RAPD, to detect global alterations of fungus expression‐related molecular marker polymorphism. Fresh Cs was collected in May for premature (stroma 1.5 cm on average) and maturing (stroma 4 cm on average) Cs, and in June for mature Cs (stroma 7 cm on average) from Kangding, Sichuan, China. Genomic DNA was isolated individually from caterpillar body, stroma and ascocarp of Cs, serving as the PCR templates, and 20 random primers were used for PCR‐RAPD. RAPD polymorphism changed in caterpillar body and stroma during Cs maturation, when number and density of the DNA bands were considered for RAPD analysis. The polymorphism was highly similar for mature stroma and ascocarp, but very different when comparing Hs and Cs samples. In conclusion, Cs is undergone a maturational change in expression of Cs component fungi in its caterpillar body and stroma. The polymorphism difference between Hs and Cs samples supports the multi‐fungi, micro‐ecology hypothesis of Cs.