• Mycobiology
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• v.46 no.4
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• pp.407-415
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• 2018

Pheromone (PHB)-receptor (RCB) interaction in the mating pheromone response pathway of Lentinula edodes was investigated using synthetic PHBs. Functionality of the C-terminally carboxymethylated synthetic PHBs was demonstrated by concentration-dependent induction of a mating-related gene (znf2) expression and by pseudoclamp formation in a monokaryotic strain S1-11 of L. edodes. Treatment with synthetic PHBs activated the expression of homeodomain genes (HDs) residing in the A mating type locus, and of A-regulated genes, including znf2, clp1, and priA, as well as genes in the B mating type locus, including pheromone (phb) and receptor (rcb) genes. The synthetic PHBs failed to discriminate self from non-self RCBs. PHBs of the B4 mating type (B4 PHBs) were able to activate the mating pheromone response pathway in both monokaryotic S1-11 and S1-13 strains, whose B mating types were B4 (self) and B12 (non-self), respectively. The same was true for B12 PHBs in the B4 (non-self) and B12 (self) mating types. The synthetic PHBs also promoted the mating of two monokaryotic strains carrying B4-common incompatible mating types ($A5B4{\times}A1B4$). However, the dikaryon generated by this process exhibited abnormally high content of hyphal branching and frequent clamp connections and, more importantly, was found to be genetically unstable due to overexpression of mating-related genes such as clp1. Although synthetic PHBs were unable to discriminate self from non-self RCBs, they showed a higher affinity for non-self RCBs, through which the mating pheromone response pathway in non-self cells may be preferentially activated.

• Journal of Microbiology and Biotechnology
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• v.15 no.3
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• pp.502-509
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• 2005

Sexual reproduction plays an important role in the biology and epidemiology of oomycete plant pathogens such as the heterothallic species Phytophthora infestans. Recent worldwide dispersal of A2 mating type strains of P. infestans resulted in increased virulence, gene transfer, and genetic variation, creating new challenges for disease management. To develop a genetic assay for mating type identification in P. infestans, we used the Amplified Fragment Length Polymorphism (AFLP) technique. The primer combination E+AT/M+CTA detected a fragment specific to A1 mating type (Mat-A1) of P. infestans. This fragment was cloned and sequenced, and a pair of primers (INF-1, INF-2) were designed and used to differentiate P. infestans Mat-A1 from Mat-A2 strains. The Mat A1-specific fragment was detected using Southern blot analysis of PCR products amplified with primers INF-1 and INF-2 from genomic DNA of 14 P. infestans Mat-A1 strains, but not 13 P. infestans Mat-A2 strains or 8 other isolates representing several Phytophthora spp. Southern blot analysis of genomic DNAs of P. infestans isolates revealed a 1.6 kb restriction enzyme (EcoRI, BamHI, AvaI)-fragment only in Mat-A1 strains. The A1 mating type-specific primers amplified a unique band under stringent annealing temperatures of $63^{\circ}C-64^{\circ}C$, suggesting that this PCR assay could be developed into a useful method for mating type determination of P. infestans in field material.

• Research in Plant Disease
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• v.16 no.2
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• pp.153-157
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• 2010

This study was examined to identify the race differentiation and distribution of mating type on Phytophthora capsici population in Korea. One hundred forty three isolates of P. capsici were collected from several locations of Korea in 2005-2007. In 2005, 20 isolates of P. capsici were collected and surveyed as A1 mating type of 75% and A2 mating type of 25%. In 2006, a total of 91 isolates were collected and separated as A1 mating type of 49.0%, A2 mating type of 42.9% and S type (sterile) of 3.3%. Isolates obtained in 2007 were similar to 2006 results. Totally, ratio of mating type of 153 isolates was confirmed that A1 type was 56.6%, A2 type was 39.2%, and S type was 4.2%. Thirteen pepper cultivars with different pathogenic response to 3 typical isolates having different mating were screened among 50 pepper cultivars and determined as race differential cultivars for investigation. The 11 races of P. capsici were found by using 13-race differential cultivars. These results indicated that at least 11 races of P. capsici are existed and confirmed race differentiation of P. capsici in pepper.

• The Korean Journal of Pesticide Science
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• v.4 no.1
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• pp.59-63
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• 2000

Isolates of Phytophthora infestans obtained from several locations of Kangwon area in 1998 and 1999 were examined on mating types and sensitivity to metalaxyl. Both A1 and A2 mating type isolates were isolated in 1998 and 1999. The majority of the P. infestans isolates were A1 mating type. About 64.3% of the isolates collected in 1998 and 99.1% in 1999 were determined as A1 mating type. Sensitivity of the P. infestans to metalaxyl was examined by measuring mycelial growth on V8 juice agar amended with $10{\mu}g/mL$ matalaxyl. About 44.6% of the isolates examined in 1988 were resistant to metalaxyl, 55.4% of the isolates were intermediate resistant, but sensitive isolate was not isolated. However, 10.5% of the isolates examined in 1999 were sensitive, 88.6% of the isolates were intermediate resistant, and 0.9% of the isolates were resistant to metalaxyl. This studies indicate that A1 mating type is displacing A2 mating type and metalaxyl sensitivity of the P. infestans isolates of Kangwon area is increasing. This result is quite different from trends of early in 1990s.

• Microbiology and Biotechnology Letters
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• v.21 no.3
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• pp.214-220
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• 1993

The mating type a of yeast, Saccharomyces cerevisiae mutant with hmla2-102 and sir3-8ts was changed to type alpha by changing the growth temperature from 25C to 35C. A temperature-sensitive expression vector system was constructed using mating factor alpha1 (Mfalpha1) gene encoding alpha factor which is expressed in the type alpha cells. Vectors with different copy numbers were constructed by joining the promoter and pre or prepro-secretion single sequence of Mfalpha1 to promoterless PHO5' gene as a reporter gene.

• Journal of Microbiology and Biotechnology
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• v.16 no.3
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• pp.423-430
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• 2006

A total of 367 isolates of Phytophthora infestans was collected from the leaf samples of late blight disease from five provinces in Korea over the three growing seasons of 2002-2004. Of the 367 isolates, 337 isolates were of the A1 mating type, and 30 isolates were of A2 mating type, showing that the majority was A1 mating type. Profiles of Gpi and Pep defined four allozyme genotypes among the total of 367 isolates. All four allozyme genotypes could be distinguished on the basis of Gpi profiles alone, whereas all isolates were homozygous at the Pep locus (100/100). The mitochondrial DNA haplotype of all isolates were the IIa haplotype. Amplification of the genomic DNAs extracted from eight isolates of each mating type by polymerase chain reaction with the selected primer (OPC-5 primer) produced a total of 20 DNA bands, of which 11 bands were polymorphic. According to the RAPD analysis using the OPC-5 primer, 106 isolates including two standard isolates were separated into 8 groups at the similarity level of 92.5%. The RAPD groups were not correlated with the allozyme genotypes and the isolated locations. All of the eight RAPD groups were identified in Gangwon-do, suggesting that Gangwon-do is the center of origin of the P. infestans in Korea. A 600-bp DNA band generated with the OPC-5 primer was specific to A1 mating type isolates, but not detected with A2 mating type, showing that the specific PCR primer can distinguish different mating types in P. infestans.

• Journal of Life Science
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• v.12 no.2
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• pp.173-181
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• 2002

This study was conducted to do the comparative analysis of mating type locus controlling the direct formation of fruiting body in Schizophyllum commune which is indigenous to North America with that of other identified mating locus. The 3120 bp Y-region nucleotide of A $\alpha$ 3 mating locus activating a developmental pathway in S. commune was determined, and appeared to have about 96% homology to S. commune 1-71 $A\alpha$3 allele indigenous to South America, showing strongly a conservative feature. This nucleotide analysis also showed above 96% homology highly in the seven presumed exons, and about 97% in the acidic rich region (AR), about 99% in homeodomain (H7), about 97% in the basic rich region (BR), about 95% in the serine rich region (Ser) respectively. In the comparative analysis to the translated polypeptide sequence, S. commune A $\alpha$ 3 mating locus containing Y-region also showed about 97% homology to the region of S. commune indigenous to North America, but the identity ratio to Y1 including Y4, Y5, Y6 different allele types was declined to about 41~49%. In the analysis of functional loci controlling mating activity, it is assumed to have a highly conservative feature showing about 98% homology in homeodomain polypeptide. Especially, it is notable that the homology ratio of above 85% in homeodomain motif between mating type alleles was higher than in the AR, BR, Ser showing about 10~50% homology.

• Microbiology and Biotechnology Letters
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• v.20 no.6
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• pp.625-629
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• 1992

This work was carried out to study physiological characteristics of Rhodosporidium toru[oides cells having two different mating types. The mating type A produces internal. cell wall-bound, and external invertases while type a produces only two invertases except external invertase. Comparing their characteristics after partial purification of internal invertases from both mating type cells, invertase from type a has decreased 15% of invertase activity only by $Mn^{2+}$ I while invertase from type A has been increased 11% of invertase activity by $Zn^{2+}$ and decreased 15% of invertase activity by $Mn^{2+}$ On the effect of enzyme inhibitor, invertase of type a was inhibited from 12% to 57% by 2-mercaptoethanol, sodium dodecyl sulfate, phenol. but invertase of type A was slightly inhibited only by phenol. The thermal stability of both invertases has showed steep inactivation at above $80^{\circ}C$ and their optimal temperatures were similar at $60^{\circ}C$ . Invertase from type A showed stability only on condition of acid from pH 3 to 6 and its opimal pH was 5.0, while invertase from type a showed stability at the wide range of pH 3-10 and its optimal pH was 4.0. And the $K_m$ values of invertases from type A and type a were $2.5{\times}10^3$M and$3.4{\times}10^3$M, respectively.

• The Korean Journal of Malacology
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• v.30 no.4
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• pp.409-413
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• 2014

Purple-colored shell individuals were discovered among normal green-colored shell individuals in artificial seed of Pacific abalone, Haliotis discus hannai, reared on an ordinary type of diatom and artificial diet. In the present study, factorial mating experiments were designed to clarify the genetic control of the variant (purple type) and normal (green type) of shell color. The parental population of purple type and green type individuals were derived from a single family between a female and male of each type of coloration. The all mating families were reared in same tank for the same breed environment. The individual of 4 type families were distinguished by paternity test using microsatellite DNA. In factorial mating experiments, all individuals offspring of GG (green type female and green type male), GP (green type female and purple type male) and PG (purple type female and green type male) mating types appeared to green type. In only PP (purple type female and purple type male) mating type, all individuals offspring appeared to purple type. The results suggested that the purple shell color is controlled by recessive purple type allele and a dominant green type allele at a single locus.

• Journal of Microbiology and Biotechnology
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• v.22 no.9
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• pp.1177-1184
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• 2012

In order to estimate how diverse the mating types in Pleurotus eryngii from different regions are, pairings between monokaryons derived from inter- and intra-groups were done. Sixteen and 15 alleles were identified at loci A and B from the 12 strains. In the P. eryngii KNR2312, widely used for commercial production, four mating loci, A3, A4, B3, and B4, were determined. Those loci, except A3, were found in 4 strains out of 12 strains. To improve breeding efficiency, especially in mating type determination, RAPD and BSA were performed to screen for a mating type specific marker. The SCAR marker 13-$2_{2100}$ was developed based on the RAPD-derived sequence typing B3 locus. The sequence analysis of 13-$2_{2100}$ revealed that it contained a conserved domain, the STE3 super-family, and consensus sequences like the TATA box and GC box. It seems likely that the SCAR marker region is a part of the pheromone receptor gene.