Altered GC- and AT-biased genotypes of Ophiocordyceps sinensis in the stromal fertile portions and ascospores of natural Cordyceps sinensis.

OBJECTIVE: To examine multiple genotypes of Ophiocordyceps sinensis in a semi-quantitative manner in the stromal fertile portion (SFP) densely covered with numerous ascocarps and ascospores of natural Cordyceps sinensis and to outline the dynamic alterations of the coexisting O. sinensis genotypes in different developmental phases. METHODS: Mature Cordyceps sinensis specimens were harvested and continuously cultivated in our laboratory (altitude 2,254 m). The SFPs (with ascocarps) and fully and semi-ejected ascospores were collected for histological and molecular examinations. Biochip-based single nucleotide polymorphism (SNP) MALDI-TOF mass spectrometry (MS) was used to genotype multiple O. sinensis mutants in the SFPs and ascospores. RESULTS: Microscopic analysis revealed distinct morphologies of the SFPs (with ascocarps) before and after ascospore ejection and SFP of developmental failure, which, along with the fully and semi-ejected ascospores, were subjected to SNP MS genotyping analysis. Mass spectra showed the coexistence of GC- and AT-biased genotypes of O. sinensis that were genetically and phylogenetically distinct in the SFPs before and after ejection and of developmental failure and in fully and semi-ejected ascospores. The intensity ratios of MS peaks were dynamically altered in the SFPs and the fully and semi-ejected ascospores. Mass spectra also showed transversion mutation alleles of unknown upstream and downstream sequences with altered intensities in the SFPs and ascospores. Genotype #5 of AT-biased Cluster-A maintained a high intensity in all SFPs and ascospores. An MS peak with a high intensity containing AT-biased Genotypes #6 and #15 in pre-ejection SFPs was significantly attenuated after ascospore ejection. The abundance of Genotypes #5‒6 and #16 of AT-biased Cluster-A was differentially altered in the fully and semi-ejected ascospores that were collected from the same Cordyceps sinensis specimens. CONCLUSION: Multiple O. sinensis genotypes coexisted in different combinations with altered abundances in the SFPs prior to and after ejection, the SFP of developmental failure, and the two types of ascospores of Cordyceps sinensis, demonstrating their genomic independence. Metagenomic fungal members present in different combinations and with dynamic alterations play symbiotic roles in different compartments of natural Cordyceps sinensis.

Differential coexistence of multiple genotypes of Ophiocordyceps sinensis in the stromata, ascocarps and ascospores of natural Cordyceps sinensis.

OBJECTIVE: To examine the differential occurrence of Ophiocordyceps sinensis genotypes in the stroma, stromal fertile portion (SFP) densely covered with numerous ascocarps, and ascospores of natural Cordyceps sinensis. METHODS: Immature and mature C. sinensis specimens were harvested. Mature C. sinensis specimens were continuously cultivated in our laboratory (altitude 2,200 m). The SFPs (with ascocarps) and ascospores of C. sinensis were collected for microscopic and molecular analyses using species-/genotype-specific primers. Sequences of mutant genotypes of O. sinensis were aligned with that of Genotype #1 Hirsutella sinensis and compared phylogenetically using a Bayesian majority-rule method. RESULTS: Fully and semiejected ascospores were collected from the same specimens. The semiejected ascospores tightly adhered to the surface of the asci as observed by the naked eye and under optical and confocal microscopies. The multicellular heterokaryotic ascospores showed uneven staining of nuclei. The immature and mature stromata, SFPs (with ascocarps) and ascospores were found to differentially contain several GC- and AT-biased genotypes of O. sinensis, Samsoniella hepiali, and an AB067719-type fungus. The genotypes within AT-biased Cluster-A in the Bayesian tree occurred in all compartments of C. sinensis, but those within AT-biased Cluster-B were present in immature and mature stromata and SPFs but absent in the ascospores. Genotype #13 of O. sinensis was present in semi-ejected ascospores and Genotype #14 in fully ejected ascospores. GC-biased Genotypes #13-14 featured large DNA segment substitutions and genetic material recombination between the genomes of the parental fungi (H. sinensis and the AB067719-type fungus). These ascosporic offspring genotypes combined with varying abundances of S. hepiali in the 2 types of ascospores participated in the control of the development, maturation and ejection of the ascospores. CONCLUSION: Multiple genotypes of O. sinensis coexist differentially in the stromata, SFPs and 2 types of C. sinensis ascospores, along with S. hepiali and the AB067719-type fungus. The fungal components in different combinations and their dynamic alterations in the compartments of C. sinensis during maturation play symbiotic roles in the lifecycle of natural C. sinensis.

Altered proteomic polymorphisms in the caterpillar body and stroma of natural Cordyceps sinensis during maturation.

OBJECTIVE: To examine the maturational changes in proteomic polymorphisms resulting from differential expression by multiple intrinsic fungi in the caterpillar body and stroma of natural Cordyceps sinensis (Cs), an integrated micro-ecosystem. METHODS: The surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) biochip technique was used to profile the altered protein compositions in the caterpillar body and stroma of Cs during its maturation. The MS chromatograms were analyzed using density-weighted algorithms to examine the similarities and cluster relationships among the proteomic polymorphisms of the Cs compartments and the mycelial products Hirsutella sinensis (Hs) and Paecilomyces hepiali (Ph). RESULTS: SELDI-TOF MS chromatograms displayed dynamic proteomic polymorphism alterations among samples from the different Cs compartments during maturation. More than 1,900 protein bands were analyzed using density-weighted ZUNIX similarity equations and clustering methods, revealing integral polymorphism similarities of 57.4% between the premature and mature stromata and 42.8% between the premature and mature caterpillar bodies. The across-compartment similarity was low, ranging from 10.0% to 18.4%. Consequently, each Cs compartment (i.e., the stroma and caterpillar body) formed a clustering clade, and the 2 clades formed a Cs cluster. The polymorphic similarities ranged from 0.51% to 1.04% between Hs and the Cs compartments and were 2.8- to 4.8-fold higher (1.92%-4.34%) between Ph and the Cs compartments. The Hs and Ph mycelial samples formed isolated clades outside of the Cs cluster. CONCLUSION: Proteomic polymorphisms in the caterpillar body and stroma of Cs change dynamically during maturation. The proteomic polymorphisms in Hs and Ph differ from those in Cs, suggesting the presence of multiple Cs-associated fungi and multiple Ophiocordyceps sinensis genotypes with altered differential protein expression in the Cs compartments during maturation. In conjunction with prior mycological and molecular observations, the findings from this proteomic study support the integrated micro-ecosystem hypothesis for natural Cs.

[Amplicon density-weighted algorithms for analyzing dissimilarity and dynamic alterations of RAPD polymorphisms of Cordyceps sinensis].

OBJECTIVE: To examine the dynamic maturational alterations of random amplified polymorphic DNA (RAPD) molecular marker polymorphism resulted from differential expressions of multiple fungi in the caterpillar body, stroma and ascocarp portion of Cordyceps sinensis (Cs). METHODS: Used the fuzzy, integral RAPD molecular marker polymorphism method with 20 random primers; used density-weighted cluster algorithms and ZUNIX similarity equations; compared RAPD polymorphisms of the caterpillar body, stroma and ascocarp of Cs during maturation; and compared RAPD polymorphisms of Cs and Hirsutella sinensis (Hs). RESULTS: Density-unweighted algorithms neglected the differences in density of the DNA amplicons. Use of the density-weighted ZUNIX similarity equations and the clustering method integrated components of the amplicon density differences in similarity computations and clustering construction and prevented from the loss of the information of fungal genomes. An overall similarity 0.42 (< the overall dissimilarity 0.58) was observed for all compartments of Cs at different maturation stages. The similarities for the stromata or caterpillar bodies of Cs at 3 maturational stages were 0.57 or 0.50, respectively. During Cs maturation, there were dynamic Low→High→Low alterations of the RAPD polymorphisms between stromata and caterpillar bodies dissected from the same pieces of Cs. The polymorphic similarity was the highest (0.87) between the ascocarp and mature stroma, forming a clustering clade, while the premature stroma and caterpillar body formed another clade. These 2 clades merged into one cluster. Another clade containing the maturing stroma and caterpillar body merged with mature caterpillar body, forming another cluster. The RAPD polymorphic similarities between Hs and Cs samples were 0.55-0.69. Hs were separated from Cs clusters by the out-group control Paecilomyces militaris. CONCLUSION: The wealthy RAPD polymorphisms change dynamically in the Cs compartments with maturation. The different RAPD polymorphism for Hs from those for Cs supports the hypothesis of integrated micro-ecosystem Cs with multiple fungi, but does not support the "single fungal species" hypothesis for Cs and the anamorph-teleomorph connection between Hs and Cs.