• Biotechnology and Bioprocess Engineering:BBE
• /
• 제9권6호
• /
• pp.440-446
• /
• 2004

Interest in in vitro study of entomopathogenic fungi, including Cordyceps species, has been increasing due to their valuable bioactive compounds and biocontrol effects. Among Cordyceps species, in vitro stromata of C militaris has been successfully produced and cultivated for industrial purposes. However, genetic study on in vitro stromata formation of C militaris has not been carried out yet. Here, relationship between mating system and perithecial stromata formation of C militaris is reported. Mating system was determined by observing perithecial stromata formation from mono-ascospore cultures and their pair-wise combinations. Certain combinations of mono-ascospore strains produced perithecial club-shaped stromata, whereas other combinations produced either no stromata or only abnormal non-perithecial stromata. Similarly, mono­ascospore cultures without combination produced either no stromata or only abnormal non­perithecial stromata. Despite obvious heterothallism, self-fertility was occasionally observed in few strains of C militaris. These observations indicated that C militaris behaves as a bipolar het­erothallic fungus and requires two mating compatible strains in order to produce regular club­shaped perithecial stromata, a fundamental requirement for its industrial cultivation.

• 한국균학회소식:학술대회논문집
• /
• 한국균학회 2009년도 추계학술대회 및 정기총회
• /
• pp.76-95
• /
• 2009

In the fungal genus Cordyceps, the type species Cordyceps militaris produces bioactive ingredients and exhibits medicinal effects as a Traditional Chinese Medicine (TCM), The fruiting bodies of C.militaris have now been mass-produced artificially and used as functional food and medicine in China. The unstable variation in forming fruiting body is however a key restrictive factor in industrial production. The genetic study on in vitro stromata formation of C. militaris has rarely been carried out. Here, we report the effects of genetic variation including the mating system on perithecial stromata formation of C. militaris. Monoconidial isolates which have both MAT1-1-1 and MAT1-2-1(genotype MAT1-1/2) could produce stromata. While the isolates only have either MAT1-1-1 or MAT1-2-1 (genotype MAT1-1 or MAT1-2) failed to produce stromata. Despite obvious heterothallism, homothallism was occasionally observed in a few isolates of C. militaris. High genetic variation was observed amongst the different monoconidial isolates of C. militaris. The unstable variation or lose of fruiting body formation was found to be caused by the inner-species high genetic variation of C. militaris. These results also indicated that C. militaris sexually behaved as both heterothallic and homothallic and required two mating type compatible in the same culture in order to produce regular clubshaped perithecial stromata.

• Mycobiology
• /
• 제38권4호
• /
• pp.282-285
• /
• 2010

Cordyceps cardinalis successfully produced its fruiting bodies from multi-ascospore isolates. However, subcultures of multiascospore isolates could not produce fruiting bodies after few generations. Fruiting body production also differed from sector to sector of the same isolate. Single ascospore isolates were then co-inoculated in combinations of two to observe the fruiting characteristics. Combinations of certain isolates produced perithecial stromata formation, whereas other combinations did not produce any fruiting bodies. These results show that C. cardinalis is a heterothallic fungus, requiring two isolates of opposite mating types for fruiting body production. It was also shown that single ascospore isolates are hermaphrodites.

• 한국균학회소식:학술대회논문집
• /
• 한국균학회 2015년도 추계학술대회 및 정기총회
• /
• pp.35-35
• /
• 2015

Pleurotus eryngii has recently become a major cultivated mushroom; it uses tetrapolar heterothallism as a part of its reproductive process. Sexual development progresses only when the A and B mating types are compatible. Such mating incompatibility occasionally limits the efficiency of breeding programs in which crossing within loci-shared strains or backcrossing strategies are employed. Therefore, understanding the mating system in edible mushroom fungi will help provide a short cut in the development of new strains. We isolated and identified pheromone and receptor genes in the B3 locus of P. eryngii and performed a functional analysis of the genes in the mating process by transformation. A genomic DNA library was constructed to map the entire mating-type locus. The B3 locus was found to contain four pheromone precursor genes and four receptor genes. Remarkably, receptor PESTE3.3.1 has just 34 amino acid residues in its C-terminal cytoplasmic region; therefore, it seems likely to be a receptor-like gene. Real-time quantitative RT-PCR (real-time qRT-PCR) revealed that most pheromone and receptor genes showed significantly higher expression in monokaryotic cells than dikaryotic cells. The pheromone genes PEphb3.1 and PEphb3.3 and the receptor gene PESTE3.3.1 were transformed into P5 (A3B4). The transformants were mated with a tester strain (A4B4), and the progeny showed clamp connections and a normal fruiting body, which indicates the proposed role of these genes in mating and fruiting processes. This result also confirms that PESTE3.3.1 is a receptor gene. In this study, we identified pheromone and receptor genes in the B3 locus of P. eryngii and found that some of those genes appear to play a role in the mating and fruiting processes. These results might help elucidate the mechanism of fruiting differentiation and improve breeding efficiency.

• 한국버섯학회지
• /
• 제4권2호
• /
• pp.48-52
• /
• 2006

느타리는 4극성 자웅이주성으로 단포자분리주는 단핵으로 자실체를 형성하지 못하는 것으로 알려져 있다. 그러나 단포자분리주는 2종류로 구분되었는데 하나는 자실체를 완전히 형성하지 못하는 AHF형 (abortive homokaryotic fruiting, AHF) 이며, 나머지 하나는 원기형성 후 완전한 자실체로 발달하는 PHF형 (Pseudo- homokaryotic fruiting, PHF)이었다. 느타리 8개 계통으로부터 단포자분리주 155개를 얻어 단핵체 자실체를 유도하여 이중에서 102개임성체를 얻었으며, 이는 65.8%에 해당되었다. 단핵 자실체는 이핵체 모균주에 비해 대부분 자실체가 빈약하였으나 일부 모균주와 유사한 크기의 자실체도 발생하였다. 이들 단핵 임성균주를 이용하여 계통간 교잡조합 11개에서 535 교잡체와 비임성균주간 교잡체 79개를 얻어 톱밥병재배를 하여 자실체 생산력을 모균주와 조사 비교하였다. 자실체 생육일수는 임성주가 비임성주간 교잡 집단에 비해 빨랐다. 병당 유효경수는 임성체간 교잡주가 모균주나 비임성교잡체보다 많았으며, 대길이도 두 집단에 비해 길었다. 그러나 대굵기와 자실체 개체중은 3개 집단간 거의 차이가 없었다. 단핵 임성체간 교잡주 집단의 병당 자실체 수량이 비임성간과 모균주 집단보다 높은 경향이었다. 모균주 집단의 자실체 수량지수를 100으로 하였을 때 임성체간 교잡체 집단은 105, 비임성간 교잡체 집단은 86으로 나타났다. 특히 $2194{\times}2344$ 조합은 59.95%, $2194{\times}2730$ 조합은 27.39%, $1982{\times}2504$ 조합은 22.43% 양친균주보다 자실체 수량이 증수되는 것으로 나타났다. 따라서 단핵 임성체를 이용한 우수 균주개발 가능성은 높다고 할 것이다.