• 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 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.

• International Journal of Industrial Entomology and Biomaterials
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• v.14 no.2
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• pp.113-119
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• 2007

Tropical tasar silkmoth Antheraea mylilta D. is an economically important insect. The wild nature and above all unsynchronized emergence of moths lead to impairment in reproductive activity. The mating in moths is low (64%-70%), leaving about 30-36% of potential females unused for seed (= egg) production. Delay in mating adversely affects the reproductive performance such as mating behaviour, fecundity and fertility. Females are more severely affected by mating delay than males. Therefore, a study was under taken to develop a method to overcome the problem so that the production of layings can be increased to meet the ever increasing demand. It was revealed from the study that out of 16 possible age combinations (from the age groups of day 0 to day 3), female and male of day 0 (4-8 hours old) excel in their reproductive performance than others (with 94.4% mating success, 284 fecundity and 91.5% hatching). Reproductive performance declined significantly even if one of the parents was older. When either of the mating pair was 1 day old, the mating declined by 28%; fecundity by 32.8%; and hatching by 40.8%. The insemination of eupyrene sperm was declined by 35.2% when both the parents are 1 day old. Mating duration of 8 hours resulted in insemination of $8.3{\times}10^5$ eupyrene sperms, which was declined by 31.6%, 48% and 55% upon lowering of mating duration to 6 hr, 4 hr and 2 hr were maintained respectively.

• Mycobiology
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• v.51 no.1
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• pp.26-35
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• 2023

The diversity of A mating type in wild strains of Lentinula edodes was extensively analyzed to characterize and utilize them for developing new cultivars. One hundred twenty-three A mating type alleles, including 67 newly discovered alleles, were identified from 106 wild strains collected for the past four decades in Korea. Based on previous studies and current findings, a total of 130 A mating type alleles have been found, 124 of which were discovered from wild strains, indicating the hyper-variability of A mating type alleles of L. edodes. About half of the A mating type alleles in wild strains were found in more than two strains, whereas the other half of the alleles were found in only one strain. About 90% of A mating type combinations in dikaryotic wild strains showed a single occurrence. Geographically, diverse A mating type alleles were intensively located in the central region of the Korean peninsula, whereas only allele A17 was observed throughout Korea. We also found the conservation of the TCCCAC motif in addition to the previously reported motifs, including ATTGT, ACAAT, and GCGGAG, in the intergenic regions of A mating loci. Sequence comparison among some alleles indicated that accumulated mutation and recombination would contribute to the diversification of A mating type alleles in L. edodes. Our data support the rapid evolution of A mating locus in L. edodes, and would help to understand the characteristics of A mating loci of wild strains in Korea and help to utilize them for developing new cultivars.

• Journal of Microbiology
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• v.40 no.4
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• pp.254-259
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• 2002

The Phytophthora infestans requires two mating types for sexual reproduction. Amplified fragment length polymorphism (AFLP) was used to specifically detect different mating types of P. infestans. The AFLP primers E+AA (5'-GACTGCGTACCAATTCAA-3') and M+CAA (5'-GATGAGTCCTGAG-TAAC AA-3') detected a fragment that is specific in the A2 mating type of P. infestans. This fragment was cloned and sequenced. Based on the sequence data, PHYB-1 and PHYB-2 primer were designed to detect the A2 mating type of P. infestans. A single 347 bp segment was observed in the A2 mating type of P. infestans, but not in the A1 mating type of P. infestans or other Phytophthora spp. Identification of mating type was performed with phenotype (sexual reproduction) and genotype (CAPs marker) methods. Two factors, the annealing temperature and template DNA quantity, were investigated to determine the optimal conditions. Using mating type-specific primers, a unique band was obtained within annealing temperatures of 57$^{\circ}C$-62$^{\circ}C$ and DNA levels of 10pg-100 ng (data not shown).

• Journal of Microbiology and Biotechnology
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• v.16 no.5
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• pp.724-730
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• 2006

A sequence characterized amplified region (SCAR) marker, which was tightly linked with the A1 mating type locus in Phytophthora infestans, was developed. During the random amplified polymorphic DNA-based phylogenic studies of 33 isolates of P infestans collected from year 2002 to 2004, we found an A1 mating type-specific DNA fragment. This 573-bp DNA fragment was generated only in the genomic DNA of the A1 mating types, when OPC-5 primer was used. Based on the specific DNA sequence, we designed the primer sets for generating the A1 mating type-specific 569-bp DNA fragment. When 33 genomic DNAs of P. infestans were subjected to PCR amplification using different primer combinations, the A1 mating type-specific DNA was amplified, when LB-1F and LB-2R primers were used. The specific 569-bp DNA fragment was generated only from all 18 A1 strains, but not from 15 A2 mating type strains. These results corresponded to the mating type discriminating bioassay of 33 isolates of P. infestans. Therefore, the primer combination of LB-1F/LB2R was chosen as a SCAR marker. Overall, this study indicates that the SCAR marker could be developed into a useful tool for mating type determination of P. infestans.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.4
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• pp.431-434
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• 2000

Maintaining maximum genetic variability is of critical importance with in-situ conservation of animal species in small populations. Marker-assisted mating (MAM) was suggested to achieve maximum heterozygosity in offspring populations. The aims of this research was to investigate and decide the effectiveness and promising types of MAM to achieve this goal. Analysis of variance with simulation data revealed that the heterozygosity in offspring populations was significantly determined by sire heterozygosity from mating of non-inbred parent animals, and significantly by sire heterozygosity and percent parental difference in offspring reproduced by inbred parents. Seven types of marker-assisted mating schemes were examined, in which offspring exhibited heterozygosity that was -0.01 to 7.37% below or above that from random mating of non-inbred parent animals, and 0.00 to 16.39% above that from random mating of inbred parent animals. The great increase in offspring heterozygosity was observed with mating by tandem maximizing sire heterozygosity, percent parental difference, and dam heterozygosity. Random mating resulted in fluctuation of offspring heterozygosity. These results suggested that MAM was a promising method for maintaining maximum offspring variability in in-situ conservation of animal species in small populations.

• Animal cells and systems
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• v.16 no.4
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• pp.337-342
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• 2012

Information about the mating behaviors of an endangered species is critical for the understanding of the natural history of the species as well as in situ and ex situ breeding programs designed to rehabilitate field populations. We describe the mating behaviors of the Mongolian racerunner (Eremias argus), an endangered species in South Korea. The mating of this species consists of precopulatory, copulatory, and postcopulatory stages and is composed of 12 different mating behaviors. During the postcopulatory stage, other males or females not involved in mating show more interference behaviors than during the precopulatory and copulatory stages. The male E. argus has an extraordinarily long postcopulatory bite, which may function as a type of mate-guarding behavior. This study is the first report on the mating behavior of a South Korean reptile.

• International Journal of Industrial Entomology and Biomaterials
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• v.16 no.2
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• pp.101-107
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• 2008

To improve mating rate of the bumblebee, Bombus terrestris, temperature, photoperiod and illumination during mating periods favorable for B. terrestris were investigated. The mating rate of queen mated at $19^{\circ}C$ was 92.1%, which was 2.1-5.9% higher than that of $22^{\circ}C$ and $25^{\circ}C$. $19^{\circ}C$ was more effective than at $22^{\circ}C$ and $25^{\circ}C$ in death rate during mating periods. The survival rate after hibernation of queen mated at $19^{\circ}C$ was 3.0-17.7% higher than that of $22^{\circ}C$ and $25^{\circ}C$. At the photoperiod regimes during mating periods, queen mated at 14 L was more effective than 12 L and 16 L in death rate during mating, survival rate after hibernation, and egg-characteristics. In case of illumination during mating periods, intensity of over 1000 lux was suitable for mating B. terrestris queen in colony development. Therefore, we supposed that mating temperature favorable for B. terrestris was $19^{\circ}C$ and photoperiod for mating was 14 L, and illumination was over 1000 lux.

• KSTLE International Journal
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• v.3 no.1
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• pp.38-42
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• 2002

Diamond-like Carbon(DLC) films were deposited on Si wafers by an RF-plasma-assisted CVD using CH$_4$gas. Tribological tests were conducted with the use of a rotating type ball on a disk friction tester with dry air. This study made use of four kinds of mating balls that were made with stainless steel but subjected to different annealing conditions in order to achieve different levels of hardness. In all load conditions, testing results demonstrated that the harder the mating materials, the lower the friction coefficient was. The friction coefficients were fecund to be lower with austenite mating balls than with fully annealed martensite balls. Conversely, the high friction coefficient found in soft martensite balls appeared to be caused by the larger contact area between the DLC film and the ball. The wear tracks on DLC films and mating balls could prove that effect. Measuring the wear track of both DLC films and mating balls revealed a similar tendency compared to the results of friction coefficients. The wear rate of austenite balls was also less than that of fully annealed martensite balls. Friction eoefficients decrease when applied leads exceed critical amount. The wear track on mating balls showed that a certain amount of material transfer occurs from the DLC film to the mating ball during a high friction process. Raman Spectra analysis Showed that the transferred materials were a kind of graphite and that the contact surface of the DLC film seemed to undergo a phase transition from carbon to graphite during the high friction process.