[Detection of multiple Ophiocordyceps sinensis mutants in premature stroma of Cordyceps sinensis by MassARRAY SNP MALDI-TOF mass spectrum genotyping].

ABSTRACT

OBJECTIVE: To examine the mutants of Ophiocordyceps sinensis (Os) in the stroma of premature Cordyceps sinensis (Cs). METHODS: Used MassARRAY single nucleotide polymorphism (SNP) MALDI-TOF mass spectrum genotyping, designed eight SNP extension primers on the basis of the scattered, multiple point mutations of known Os mutants within their internal transcribed spacer (ITS) segments, and examined the Os mutant genotypes relating to the GC-biased Os genotype (gb #AB067721) in premature Cs stroma. RESULTS: The two AT-biased genotypes and the GC-biased Os were simultaneously detected in premature Cs stroma. SNP genotyping also detected at least two other Os genotypes of unknown sequences. CONCLUSION: Coexistence of the three known Os genotypes indicates the existence of possible transition point mutations within Os genes during germination and early maturation of Cs. Simultaneous detection of at least two unknown genotypes coexisting with those known mutants possibly evidences the transversion mutations within Os genes.