• BMB Reports
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• 제39권4호
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• pp.457-463
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• 2006

Insulin resistance is commonly observed in patients prior to the development of type 2 diabetes and may predict the onset of the disease. We tested the hypothesis that impairment in insulin stimulated glucose-disposal in insulin resistant patients would be reflected in the gene expression profile of skeletal muscle. We performed gene expression profiling on skeletal muscle of insulin resistant and insulin sensitive subjects using microarrays. Microarray analysis of 19,000 genes in skeletal muscle did not display a significant difference between insulin resistant and insulin sensitive muscle. This was confirmed with real-time PCR. Our results suggest that insulin resistance is not reflected by changes in the gene expression profile in skeletal muscle.

• 한국동물위생학회지
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• 제46권1호
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• pp.35-45
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• 2023

Pathogenic Escherichia coli is the cause of a wide range of diseases in pigs, including diarrhea, edema disease, and septicemia. Diarrhea caused E. coli may result in significant economic losses, making pathogenic E. coli an important pathogen for the swine industry. This study investigated the prevalence of virulence factor genes, antimicrobial resistance phenotypes, and resistance genes in E. coli isolated from feces of piglets in Korea between 2017 and 2020. As a result, 119 pathogenic E. coli isolates were obtained from 601 fecal samples. The F4 adhesin gene and the STb enterotoxin gene were commonly present in E. coli isolated from diarrhea samples. The dominant virulotypes of isolates from diarrhea samples were STb, Stx2e, and F4:LT:STb. More than 80% of the screened isolates were resistant to ampicillin, sulfisoxazole, chloramphenicol, or tetracycline. To confirm the resistance mechanisms for β-lactam or quinolone, we investigated the genotypic factors of resistance. Each of the ceftiofur-resistant E. coli produced an extended-spectrum β-lactamase encoded by bla_CTX-M-14, bla_CTX-M-27, and bla_CTX-M-55. And all ciprofloxacin-resistant E. coli harbored mutations in quinoloneresistance-determining-regions. In addition, some of the ciprofloxacin-resistant E. coli contained the plasmid-mediated-quinolone-resistance genes such as qepA, qnrB1, or qnrD. This study has confirmed that the F4 fimbria and the STb enterotoxin are the most predominant in pathogenic E. coli isolated from piglets with diarrhea in Korea and there is a great need for responsible and prudent use of antimicrobials to treat colibacillosis.

• Asian-Australasian Journal of Animal Sciences
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• 제22권4호
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• pp.465-470
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• 2009

The chicken Mx gene has been regarded as a candidate gene for resistance to avian influenza virus (AIV). In this study, three groups of chickens with homozygotes (AA, GG) and heterozygotes (AG) of the resistant (A) and susceptible alleles (G) to AIV of the Mx gene were constructed from a line of dwarf egg-type chickens. These chickens were not examined for their resistant activities to AIV because the differential resistance had only been detected in vitro. The birds of the three groups were vaccinated with inactivated H5N2 AIV vaccine and the level of hemagglutination inhibition (HI) antibody to AIV was detected. The association between disease resistant activity to AIV and antibody response to AIV vaccination in the three groups was analyzed. The chickens with homozygous resistant allele A showed the lowest antibody levels, whereas the heterozygous chickens (AG) presented the highest antibody level after the boosting vaccination, which indicates that the efficiency of artificial selection on the resistant allele of Mx gene will be compromised since the homozygotes of the allele presented the weakest antibody response to the corresponding vaccine.

• Plant Breeding and Biotechnology
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• 제7권3호
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• pp.272-286
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• 2019

Developing elite hybrid rice varieties is one important objective of rice breeding programs. Several genes related to male sterilities, restores, and pollinators have been identified through map-based gene cloning within natural variations of rice. These identified genes are good targets for introducing genetic traits in molecular breeding. This study was conducted to breed elite hybrid lines with major genes related to hybrid traits and disease/insect resistance in 240 genetic resources and F₁ hybrid combinations of rice. Molecular markers were reset for three major hybrid genes (S5, Rf3, Rf4) and thirteen disease/insect resistant genes (rice bacterial blight resistance genes Xa3, Xa4, xa5, Xa7, xa13, Xa21; blast resistance genes Pita, Pib, Pi5, Pii; brown planthopper resistant genes Bph18(t) and tungro virus resistance gene tsv1). Genotypes were then analyzed using molecular marker-assisted selection (MAS). Biological assay was then performed at the Red River Delta region in Vietnam using eleven F₁ hybrid combinations and two control vatieties. Results showed that nine F₁ hybrid combinations were highly resistant to rice bacterial blight and blast. Finally, eight F₁ hybrid rice varieties with resistance to disease/insect were selected from eleven F₁ hybrid combinations. Their characteristics such as agricultural traits and yields were then investigated. These F₁ hybrid rice varieties developed with major genes related to hybrid traits and disease/insect resistant genes could be useful for hybrid breeding programs to achieve high yield with biotic and abiotic resistance.

• Plant Biotechnology Reports
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• 제2권1호
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• pp.13-20
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• 2008

Potato (Solanum tuberosum L.), one of the most important food crops, is susceptible to a number of devastating fungal pathogens in addition to bacterial and other pathogens. Producing disease-resistant cultivars has been an effective and useful strategy to combat the attack of pathogens. Potato was transformed with Agrobacterium tumefaciens strain EHA101 harboring chitinase, (ChiC) isolated from Streptomyces griseus strain HUT 6037 and bialaphos resistance (bar) genes in a binary plasmid vector, pEKH1. Polymerase chain reaction (PCR) analysis revealed that the ChiC and bar genes are integrated into the genome of transgenic plants. Different insertion sites of the transgenes (one to six sites for ChiC and three to seven for bar) were indicated by Southern blot analysis of genomic DNA from the transgenic plants. Expression of the ChiC gene at the messenger RNA (mRNA) level was confirmed by Northern blot analysis and that of the bar gene by herbicide resistance assay. The results obviously confirmed that the ChiC and bar genes are successfully integrated and expressed into the genome, resulting in the production of bialaphos-resistant transgenic plants. Disease-resistance assay of the in vitro and greenhouse-grown transgenic plants demonstrated enhanced resistance against the fungal pathogen Alternaria solani (causal agent of early blight).

• The Plant Pathology Journal
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• 제37권2호
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• pp.194-199
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• 2021

Blackleg is a serious disease in Brassica plants, causing moderate to severe yield losses in rapeseed worldwide. Although China has not suffered from this disease yet (more aggressive Leptosphaeria maculans is not present yet), it is crucial to take provisions in breeding for disease resistance to have excellent blackleg-resistant cultivars already in the fields or in the breeding pipeline. The most efficient strategy for controlling this disease is breeding plants with identified resistance genes. We selected 135 rapeseed accessions in Sichuan, including 30 parental materials and 105 hybrids, and we determined their glucosinolate and erucic acid content and confirmed 17 double-low materials. A recently developed single-nucleotide polymorphism (SNP) marker, SNP_208, was used to genotype allelic Rlm1/rlm1 on chromosome A07, and 87 AvrLm1-resistant materials. Combined with the above-mentioned seed quality data, we identified 11 AvrLm1-resistant double-low rapeseed accessions, including nine parental materials and two hybrids. This study lays the foundation of specific R gene-oriented breeding, in the case that the aggressive Leptosphaeria maculans invades and establishes in China in the future and a robust and less labor consuming method to identify resistance in canola germplasm.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.112-112
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• 2017

Rice blast caused by Magnaporthe oryzae is one of the most serious diseases that affect the quantity and quality of rice production. The use of resistant rice varieties would be the most effective way to control the rice blast. However R gene incorporation into the rice variety takes time and pathogen could overcome the R gene effects after for a while. For monitoring the rice blast resistance gene distribution in Korean varieties, the four major blast resistance genes against M. oryzae were screened in a number of Korean rice varieties using molecular markers. Of the 120 rice varieties tested, 40 were found to contain the Pi-5 gene, 25 for the Pi-9 gene, 79 for Pi-b and 40 for the Pi-ta gene. None of these rice varieties includes tested 4 R genes. 3 R genes combination, Pi-5/Pi-9/Pi-b, Pi-5, Pi-9.Pi-ta, or Pi-9/Pi-b/Pi-ta were found in 12 varieties, the rice blast disease severity were showed as resistant in the rice verities containing Pi-9/Pi-b/Pi-ta R genes combination, respectively. Also pathogenic diversity of M. oryzae isolates collected in the rice field from 2004 to 2015 in rice field in Korea were analyzed using rice blast monogenic lines, each harboring a single blast resistance gene. Compatibility of blast isolates against rice blast monogenic lines carrying the resistance genes Pi5, Pi9, Pib, and Piz showed dynamic changes by year. It indicates that pathogen has high evolutionary potential adapted host resistances to increase fitness and would lead to rice blast resistance bred into the cultivar becoming ineffective eventually.

• The Plant Pathology Journal
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• 제37권5호
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• pp.489-493
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• 2021

Bacterial canker is a devastating disease of kiwifruit caused by the bacterium Pseudomonas syringe pv. actinidiae. Canker disease of kiwifruit in Korea has been controlled using streptomycin for more than two decades. Four streptomycin-resistant strains, belonging to biovar 2, which are found only in Korea, were collected between 2013 and 2014 from different orchards located in Jeju, Korea. The genetic background for streptomycin resistance among P. syringe pv. actinidiae strains were determined by examining the presence of strA-strB or aadA, which are genes frequently found in streptomycin-resistant bacteria, and a point mutation at codon 43 in the rpsL gene. All four streptomycin-resistant strains of P. syringe pv. actinidiae investigated in this study contained strA-strB as a resistant determinant. The presence of the aadA gene and a mutation in codon 43 of the rpsL gene was not identified.

• 식물병연구
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• 제10권1호
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• pp.73-77
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• 2004

본 연구는 우리나라에서 육성된 대안벼, 화선찰벼, 대진벼, 내풍벼, 화진벼, 수라벼의 흰잎마름병 저항성 유전자를 밝히기 위하여 실시하였다. 이들 품종을 단일 저항성 유전자를 갖고 있는 준동질계통과 교배한 F$_1$ 개체와 F$_2$ 집단을 Kl race 균주와 일본의 race 1을 사용하여 분석하였다. 검정품종은 모두 Xa1 저항성 유전자를 갖고 있는 IRBB101 계통과 대립관계를 나타냈고 Xa4와 xa-5 유전자를 갖고 있는 IRBB104와 IRBB105 계통과는 비대립 관계를 나타내었다. 따라서 대안벼, 화선찰벼, 대진벼, 내풍벼, 화진벼, 수라벼가 Xal 저항성 유전자를 갖고 있는 것으로 판단되었다.

• Parasites, Hosts and Diseases
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• 제50권4호
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• pp.379-384
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• 2012

Resistance of Plasmodium spp. to anti-malarial drugs is the primary obstacle in the fight against malaria, and molecular markers for the drug resistance have been applied as an adjunct in the surveillance of the resistance. In this study, we investigated the prevalence of mutations in pvmdr1, pvcrt-o, pvdhfr, and pvdhps genes in temperate-zone P. vivax parasites from central China. A total of 26 isolates were selected, including 8 which were previously shown to have a lower susceptibility to chloroquine in vitro. For pvmdr1, pvcrt-o, and pvdhps genes, no resistance-conferring mutations were discovered. However, a highly prevalent (69.2%), single-point mutation (S117N) was found in pvdhfr gene. In addition, tandem repeat polymorphisms existed in pvdhfr and pvdhps genes, which warranted further studies in relation to the parasite resistance to antifolate drugs. The study further suggests that P. vivax populations in central China may still be relatively susceptible to chloroquine and sulfadoxine-pyrimethamine.