• 한국식물병리학회지
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• 제10권2호
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• pp.92-98
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• 1994

Phytophthora infestans populations collected from various geographical locations of Korea in 1991 and 1993 were analyzed for mating types and responses to metalaxyl. Both A1 and A2 mating type isolates were detected in 1991. The majority of the isolates were A2 mating type, but no A1 mating type was detected in 1993. About 40% of the isolates collected in 1991 were resistant to metalaxyl, and the distribution of metalaxyl-resistant isolates of P. infestans was strongly associated with their geographic origins in Korea. Metalaxyl-resistant isolates with EC50 values > 50$\mu\textrm{g}$/ml were collected from the northern provinces of Kangwon, Kyungbuk, and Chonbuk, but not from the southern provinces of Kyungnam, Chonnam, and Jeju in 1991. The drastic increase in the degree of quantitative resistance to metalaxyl was detected among the isolates from the southern provinces during 1991~1993. More than 50% of the isolates collected from the southern provinces of Kyungnam and Chonnam in 1993 had EC50 values >50$\mu\textrm{g}$/ml. The province of Kangwon had isolates with the greatest resistance to metalaxyl. this alpine areas might be the origin of metalaxyl-resistant isolates of P. infestans in Korea. The A2 genotype with metalaxyl resistance appears to be displacing the A1 genotype which is presently the predominant genotype in Korea.

• Asian-Australasian Journal of Animal Sciences
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• 제18권4호
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• pp.463-469
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• 2005

An attempt was made to analyze the factors affecting mating performance of rams in pen mating systems. Due to many types of social interactions, mating performance of rams may decrease or increase. Six intact Muzaffarnagari rams were used and divided into three dominant subordinate pairs by food and ewe competition test. For dominant rams subordinate ram became competitor and vice versa. In the first experiment, ram was exposed to ewe but the competitor ram was kept outside the pen with the facility of visibility only. In the second experiment each ram was exposed to ewe along with the competitor ram and in third experiment ram was exposed to ewes (two) along with competitor ram in observation pen. Recordings of different mating and agonistic behaviour were done in all the experiments. It was found that subordinate ram's mating behaviour was inhibited by mere presence of a dominant ram out side without physical contact. However, when ram exposed to oestrus ewe(s) along with competitor ram, both dominant and subordinate rams spent much of their time in guarding activities instead of mating. In addition dominant ram tried to curtail the subordinate ram mating by agonistic interaction like fight and butting. Different guarding activities were observed either as active or passive type depending on level of dominanace. It was concluded that in a limited space the interaction of two or more rams might affect the number of services adversely.

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

• Journal of Microbiology and Biotechnology
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• 제24권3호
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• pp.408-420
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• 2014

Yeast surface-displayed antibody libraries provide an efficient and quantitative screening resource for given antigens, but suffer from typically modest library sizes owing to low yeast transformation efficiency. Yeast mating is an attractive method for overcoming the limit of yeast transformation to construct a large, combinatorial antibody library, but the optimal conditions have not been reported. Here, we report a large synthetic human Fab (antigen binding fragment) yeast surface-displayed library generated by stepwise optimization of yeast mating conditions. We first constructed HC (heavy chain) and LC (light chain) libraries, where all of the six CDRs (complementarity-determining regions) of the variable domains were diversified mimicking the human germline antibody repertoires by degenerate codons, onto single frameworks of VH3-23 and $V{\kappa}1$-16 germline sequences, in two haploid cells of opposite mating types. Yeast mating conditions were optimized in the order of cell density, media pH, and cell growth phase, yielding a mating efficiency of ~58% between the two haploid cells carrying HC and LC libraries. We constructed two combinatorial Fab libraries with CDR-H3 of 9 or 11 residues in length with colony diversities of more than $10^9$ by one round of yeast mating between the two haploid HC and LC libraries, with modest diversity sizes of ${\sim}10^7$. The synthetic human Fab yeast-displayed libraries exhibited relative amino acid compositions in each position of the six CDRs that were very similar to those of the designed repertoires, suggesting that they are a promising source for human Fab antibody screening.

• 한국수정란이식학회지
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• 제31권1호
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• pp.65-72
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• 2016

This study was conducted to examine effects of mating type on the growth traits in an $F_2$ population produced by reciprocal intercrosses between Landrace and the Jeju Native Black pig (JBP). The $F_2$ progeny were produced by two different mating types based on the grand dams of founder breeds JBP (Cross_1) and Landrace (Cross_2). The body weights at 21 days after birth (BW21D) was significantly different between Cross_1 and Cross_2 (P<0.05), showing that the BW21D of Cross_1 has about 0.25 kg heavier than Cross_2. The significant differences were found between males and females for the growth traits including the body weights (BWB, BW21D, BW70D and BW140D) and average daily gains (ADG, eADG and lADG) (P<0.05). Males were heavier BWB, BW21D and BW140D levels, and higher ADG and lADG levels than females. On the other hand, females had heavier BW70D and higher eADG levels than those of males. When considering the mating types and sex simultaneously the Cross_2 males had the heaviest BW140D among the combinations of cross and sex. In conclusion, it is desirable to choose Landrace as grand dams in the reciprocal intercrosses between Landrace and JBP for producing their progeny construction and to plan the production of $F_2$ males for industrial purposes. These results suggested that it may be one of useful strategies to improve the productivity through out selection of the mating type of founder breeds and the progeny sex, especially in Landrace, JBP and their related populations.

• The Plant Pathology Journal
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• 제17권5호
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• pp.276-280
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• 2001

Fusarium isolates of Gibberella fujikuroi species complex were obtained from sorghum grown in five provinces of Korea in 1996 and 1997. These isolates were characterized based on their mating behavior, mycotoxin production, and vegetative compatibility. Only three mating populations (A, D, and F) were recovered from a total of 155 isolates examined. The relative frequency of the mating populations was significantly different: F was predominant (80%), while D and A were observed at low frequencies of 9% and 3%, respectively. Female fertile isolates were more common within F (44 our of 124) than D (2 out of 14), while none of the five A isolates were female fertile. The inbreeding effective population sizes ($\textrm{N}_e$)for mating type and male/hermaphrodite ratios in mating populations A and D produced significant amounts of fumonisins, while F isolates produced none or only traces of fumonisin B$_1$. In contrast. F isolates produced higher amounts of moniliformin (average of 3,820 ppm) than A and D isolates (averages of 77 and 1,819 ppm, respectively). Fifty-one isolates were tested for vegetative compatibility using nitrogen non-utilization mutants of each isolate, and 44 vegetative compatibility groups (VCGs) were identified. A single VC type (VC1) was found in all of the five A isolates examined. Six of the D isolates examined consisted of three VC types: two for VC2, two for VC3, and the rest for VC4. All of the F isolates tested were incompatible in every combination and , thus, each constituted a unique VCG.

• Journal of Microbiology and Biotechnology
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• 제16권3호
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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.

• Interdisciplinary Bio Central
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• 제3권4호
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• pp.13.1-13.8
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• 2011

Previous research has established the existence of individual differences with regards to individuals' optimum time of well-functioning; specifically in terms of being either morning or evening oriented. An association has also emerged between being more evening, as opposed to morning, oriented and having a greater number of sexual partners. The aim of the present study was to investigate whether "eveningness" in males is an evolved sexually dimorphic trait consistent across different cultures. A sample of 179 male Sri Lankan men residing in two different cultural and economic settings, Italy and Sri Lanka, were administered the Morningness-Eveningness Questionnaire (MEQ) followed by assessing their sexual behavior history. The results robustly portrayed a highly significant main effect of MEQ types highlighting the twofold sexual success enjoyed by the evening individuals in both regional locations. Morning oriented individuals, showed a stronger preference for going out and partying than evening-types, suggesting that the higher mating success of evening types is not due to their different lifestyles allowing more opportunities to encounter females. However, evening types exhibited a preference for flirtatious behaviors in the later part of the day. Shoulder-to-hip and handgrip strength, as measures of testosterone levels, were not significantly associated with eveningness. The results are discussed in terms of sexual selection and its interplay with human cultural variation.

• 한국식물병리학회지
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• 제10권3호
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• pp.192-196
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• 1994

Two hundred and fourty-seven isolates of Phytophthora infestans obtained from infested potato leaves from the spring of 1991 to the fall of 1993 from potato fields in various regions of Korea were tested for their fungicides resistances. A total of 20.9% isolates were not suppressed at 50 ppm of metalaxyl in 1991, but isolates from 1993 were suppressed at 50 ppm of metalaxyl. Ten resistant isolates and 10 susceptible isolates to metalaxyl were selected and tested against oxadixyl, fosetyl-Al, and phosphorous acid. Effectiveness of these chemicals were no better than that of metalaxyl. Dimethomorph suppressed all isolates at 1 $\mu\textrm{g}$/ml suggesting that it might be a potential chemical to control Phytophthora infestans. Mating types of all isolates from diseased leaves in 1993 turned out to be A2 type.

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