• Microbiology and Biotechnology Letters
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• v.22 no.1
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• pp.1-6
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• 1994

We have studied the relation between Ca$^{2+}$-ATPase and trigger peptidase(TPase) which are membeane protein well known as their significant role for signal transduction of mating pheromone in heterobasidiomycetous yeast. Rhodosporidium toruloides. We found out that there were Ca $^{2+}$-ATPase and TPase together in isolated calmodulim binding protein(CBP), usion calmodulin affinity column chromatography after solubilization of mation type a cell membrane protein, and that the dependence of enzyme activity of both the enzymes on Ca$^{2+}$, phospholipid and nonionic detergent are similar. However, Ca$^{2+}$-ATPase hed quite absolute dependence on calmodulin and, on the other hand, TPase didn't have any dependence. Judging from the fact that there are both enzymes in CBP which the dependence of calmodulin are quite different, we found out that both enzymes were made to their compound and existed in mating type a cell membrane.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.85.1-85
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• 2003

In most ascomycetes, a single mating type locus, MAT, with two alternate forms (MAT1-1 and MAT1-2) called idiomorphs, controls mating ability. In heterothallic ascomycetes these alternate idiomorphs reside in different nuclei. In contrast, most homothallic ascomycetes carry both MAT1-1 and MAT1-2 in a single nucleus, usually closely linked. An example of the latter is Gibberella zeae, a producer of mycotoxins such as trichothecene and zearalenone that threaten human and animal health. We asked if G. zeae could be made strictly heterothallic by manipulation of MAT. Targeted gene replacement was used to differentially delete MAT1-1 or MAT1-2 from a wild type haploid MAT1-1 MAT1-2 strain, resulting in MAT1-1；mat1-2, mat1-1；MAT1-2 strains that were self-sterile, yet able to cross to wild type testers and more importantly, to each other. These results indicated that differential deletion of MAT idiomorphs eliminates selfing ability of G. zeae, but the ability to outcross is retained. To our knowledge, this is the first report of complete conversion of fungal reproductive strategy from homothallic to heterothallic by targeted manipulation of MAT. Practically, this approach opens the door to simple and efficient procedures for obtaining sexual recombinants of G. zeae that will be useful for genetic analyses of mycotoxin production and other traits, such as ability to cause disease.

• The Plant Pathology Journal
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• v.17 no.5
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• pp.281-289
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• 2001

We analyzed 88 strains of Gibberella fujikuroi (Analmorph: Fusarium section Liseola) from maize in Korea for mating population, mating type, fumonisin production vegetative compatibility, and random amplified polymorphic DNA (RAPD) patterns. We found 50 strains that were MATA-2, 22 that were MATA-1, 1 that was MATD-1, and 15 that were not reproducibly fertile with any of the mating type testers. Of the 50 MATA-2, 15 were female fertile, while 10 of the 22 MATA-1 strains were female fertile. A total of 1,138 nitrate non-utilizing (nit) mutants were recovered from a total of 88 strains. These strains were grouped into 39 vegetative compatability groups (VCGs) by demonstrating heterokaryosis between nit mutants. A single maize ear could be infected by more than one VCG of F. moniliforme. RAPD analysis measured genetic diversity among 63 strains of F. moniliforme. Several VCGs were distinguished by RAPD fingerprinting patterns. Most strains produced significant levels of fumonisins. However, 6 MATA-2 strains from a single VCG produced higher levels of fumonisin $\textrm{B}_3$ than that of fumonisin $\textrm{B}_1$ or $\textrm{B}_2$. From these data, we concluded that most Korean strains of F. moniliforme associated with maize belonged to mating population A and produced significant levels of fumonisins. Futhermore, RAPD analysis could differentiate strains associated with different VCGs.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.6
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• pp.1246-1251
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• 1997

When the membrane protein fraction of mating type a cells of heterobasidiomycetous yeast R. toruloides was phosphorylated in vitro, two phosphorylated proteins of 72Kd and 57Kd were detected on SDS-polyacryamide gel. The phosphorylation reaction was inhibited by rhodotorucine A(Rh. A) which is a sexual pheromone secreted by mating type A cells. The inhibition of phosphorylation by Rh. A was dependent on $Ca^{2+}$, and independent on $Mg^{2+}$ or calmodulin. When adding trigger peptidase(TPase) inhibitor, antipain, no inhibition of phosphory was observed. Also, by adding the trysin-digested product of Rh. A, the phosphorylation was inhibited as the action of Rh. A. From these results, it is expected that the inhibition of membrane protein phosphorylation should be caused by the digested product of Rh. A with TPase.

• The Korean Journal of Mycology
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• v.28 no.1
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• pp.22-25
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• 2000

This study was carried out to compare DNA sequence of mating type locus concerning with direct formation of fruiting body in Schizophyllum commune which is growing in North America with that of same species growing in South America. The nucleotide sequence appeared to have about 96% homology to 1-71 $A{\alpha}3$ allele from South America strain, showing a conservative feature. The polypeptide sequence showed about 82% homology when compared partially with mating activity region of 1-71 $A{\alpha}3$ allele. In addition, this polypeptide sequence indicated 74% and 82% identity in homeodomain and acidic-rich regions known as a transcription factor respectively.

• Journal of Microbiology and Biotechnology
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• v.27 no.7
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• pp.1223-1232
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• 2017

Cordyceps militaris, a member of Ascomycota, a mushroom referred to as caterpillar Dong-chung-ha-cho, is commercially valuable because of its high content of bioactive substances, including cordycepin, and its potential for artificial cultivation. Cordycepin (3'-deoxyadenosine) is highly associated with the pharmacological effects of C. militaris. C. militaris is heterothallic in that two mating-type loci, idiomorph MAT1-1 and MAT1-2, exist discretely in two different spores. In this study, nine C. militaris strains were mated with each other to prepare newly bred strains that produced a larger amount of cordycepin than the parent strains. Nine strains of C. militaris were identified by comparing the internal transcribed spacer sequence, and a total of 12 single spores were isolated from the nine strains of C. militaris. After the MAT idiomorph was confirmed by PCR, 36 mating combinations were performed with six single spores with MAT1-1 and the others with MAT1-2. Eight mating combinations were successfully mated, producing stroma with perithecia. Cordycepin content analysis of all strains by high-performance liquid chromatography revealed that the KASP4-bred strain produced the maximum cordycepin among all strains, regardless of the medium and stroma parts. Finally, universal rice primer-PCR was performed to demonstrate that the bred strains were genetically different from the parental strains and new C. militaris strains. These results may be related to the recombination of genes during mating. The newly produced strains can be used to meet the industrial demand for cordycepin. In addition, breeding through mating suggests the possibility of producing numerous cordycepin-producing C. militaris strains.

• Mycobiology
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• v.51 no.6
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• pp.452-462
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• 2023

Opportunistic infections due to Cryptococcus neoformans and C. gattii species complexes continue to rise unabated among HIV/AIDS patients, despite improved antifungal therapies. Here, we collected a total of 20 environmental and 25 presumptive clinical cryptococcal isolates from cerebrospinal fluid (CSF) samples of 175 patients enrolled in an ongoing clinical trial Ambition 1 Project (Botswana-Harvard Partnership). Identity confirmation of the isolates was done using MALDI-TOF MS and PCR. We describe the diversity of the isolates by PCR fingerprinting and sequencing (Oxford Nanopore Technology) of the intergenic spacer region. Mating types of the isolates were determined by amplification of the MAT locus. We report an unusual prevalence of 42.1% of C. neoformans × C. deneoformans hybrids Serotype AD (n = 16), followed by 39.5% of C. neoformans Serotype A (n = 15), 5.3% of C. deneoformans, Serotype D (n = 2), 7.9% of C. gattii (n = 3), and 5.3% of C. tetragattii (n = 2) in 38 representative isolates that have been characterized. Mating type-specific PCR performed on 38 representative environmental and clinical isolates revealed that 16 (42.1%) were MATa/MAT𝛼 hybrids, 17 (44.7%) were MAT𝛼, and five (13.2%) possessed MATa mating type. We used conventional and NGS platforms to demonstrate a potential link between environmental and clinical isolates and lay a foundation to further describe mating patterns/history in Botswana.

• Journal of Mushroom
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• v.11 no.1
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• pp.1-8
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• 2013

In this study, twelve of Lepista nuda were collected from various localities in Korea. Also thirteen exotic L. nuda species were collected from Japan, France, Switzerland and Portugal. Spores were isolated under optical microscope. These spores were placed on the surface of YM medium for inducing to germination. Eleven mating-groups were selected by morphological characters of fruit body such as size, color and stipe patterns. Intra-isolate crosses were made between two single-spore isolates derived from mating-groups. Also, dikaryotic crossing using the isolates from L. nuda were carried out to evaluated tetrakaryon formation. Cross-mating compatibility tests also verified its dikaryotic state by microscopic or molecular genetic observation of clamp connection and Random Amplified Polymorphic DNA (RAPD) band pattern. To analyze the growth rate of hybrids and parents mycelium in dikaryons obtained from compatible mating groups were placed on PDA medium. Intra-isolate crosses determined eleven mating-groups within L. nuda. The typical clamp connection were mostly observed in mating-groups of Korean L. nuda in $K1{\times}K2$, $K1{\times}K3$, $K1{\times}K4$, $K1{\times}K6$, $K1{\times}K5$, $K2{\times}K4$, $K2{\times}K3$, $K2{\times}K6$, $K3{\times}K4$, $K4{\times}K5$, and $K4{\times}K6$. Korean L. nuda type of dikaryon, shown to cross-incompatibility with L. sordida, it seemed that mating induce more rapidly than wild types in a view of growth rate. In conclusion, it would be useful to improve mass production with better morphological characteristics through a special mating of L. nuda.

• Journal of Mushroom
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• v.1 no.1
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• pp.9-14
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• 2003

To breed new superior strains, collected strains were characterized and then several white strains were selected as parents. Monokaryons from the parents were isolated and studied. All tested white strains showed same mating genotype. Growth rate of monokaryons were lower than collected dikaryons. New dikaryotic strains were derived from inbreeding method, which means mating between monokaryotic isolates from different white strains having same mating genotype. Some of them showed higher yields of fruitbody than their parents. Specially Fv 4-1 strain showed the best productivity. Furthermore some mating combination showed cytoplasmic effect, when they mated reciprocally.

• Korean Journal Plant Pathology
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• v.14 no.5
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• pp.445-451
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• 1998

A severe Phytophthora rot of strawberry caused by a species of Phytophthora has been widely occurred at major cultivation areas of Kimhae on August in 1997. Incidence of the disease was obtained in the range of 69.2~83.6% in surveyed 4 fields and showed an average of 75.2%. A species of Phytophthora was mostly isolated from the crown of infected strawberry plants and all the isolates were identified as P. nicotianae var. nicotianae (=P. parasitica). The fungus showed strong pathogenicity on strawberry by inoculation test. As a result of the leaf inoculation using mycelial disks of the fungus, both leaves and petioles were darkly browned, and were finally blighted. As a result of the root inoculation of zoospore suspension, both roots and crowns were rotten with dark brown. Although the fungus produced sporangia either on V-8 juice agar medium or liquid medium, the sporangia observed on the liquid medium appeared to be broadly turbinate and noncaducous. Moreover the fungus cultured on the liquid medium often produced sporangia having two papilla. The number of zoospores in sporangia was found to be ranged from 3 or 4 to as many as 20 or 25. In addition, the released zoospore from the sporangium became the cystospore during the prolonged culture of the fungus. The sporangia were measured as av. 49$\times$35 ${\mu}{\textrm}{m}$ with l/b ratio of 1.43. All isolates from crowns were heterothallic and A1 mating type since oospores were abundantly formed on clarified V-8 juice agar by dual culture with P. capsici A2 mating type. Aplerotic oospores were sized 24-26 ${\mu}{\textrm}{m}$. Antheridia were always amphigynous and recoreded an average of 12$\times$10 ${\mu}{\textrm}{m}$. Hyphal swlling were easily observed, and terminal or intercalary chlamydospores were abundantly formed on V-8 juice agar as well as in C/Z solution and sized av. 28.2 ${\mu}{\textrm}{m}$. This is the first report of Phytophthora rot of strawberry in Korea.