• Journal of Microbiology
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• v.43 no.spc1
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• pp.110-117
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• 2005

Salmonella enterica serovar Typhimurium causes human gastroenteritis and a systemic typhoid-like infection in mice. A critical virulence determinant of Salmonella is the ability to invade mammalian cells. The expression of genes required for invasion is tightly regulated by environmental conditions and a variety of regulatory genes. The hilA regulator encodes an OmpR/ToxR family transcriptional regulator that activates the expression of invasion genes in response to both environmental and genetic regulatory factors. Work from several laboratories has highlighted that regulation of hilA expression is a key point for controlling expression of the invasive phenotype. A number of positive regulators of hilA expression have been identified including csrAB, sirA/barA, pstS, hilC/sirC/sprA, fis, and hilD. HilD, an AraC/XylS type transcriptional regulator, is of particular importance as a mutation in hilD results in a 14-fold decrease in chromosomal hilA::Tn5lacZY-080 expression and a 53-fold decrease in invasion of HEp-2 cells. It is believed that HilD directly regulates hilA expression as it has been shown to bind to hilA promoter sequences. In addition, our research group, and others, have identified genes (hilE, hha, pag, and lon) that negatively affect hilA transcription. HilE appears to be an important Salmonella-specific regulator that plays a critical role in inactivating hilA expression. Recent work in our lab has been directed at understanding how environmental signals that affect hilA expression may be processed through a hilE pathway to modulate expression of hilA and the invasive phenotype. The current understanding of this complex regulatory system is reviewed.

• Journal of Animal Science and Technology
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• v.63 no.4
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• pp.751-758
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• 2021

The recessive white (locus c) phenotype observed in chickens is associated with three alleles (recessive white c, albino c^a, and red-eyed white c^re) and causative mutations in the tyrosinase (TYR) gene. The recessive white mutation (c) inhibits the transcription of TYR exon 5 due to a retroviral sequence insertion in intron 4. In this study, we genotyped and sequenced the insertion in TYR intron 4 to identify the mutation causing the unusual white plumage of Yeonsan Ogye chickens, which normally have black plumage. The white chickens had a homozygous recessive white genotype that matched the sequence of the recessive white type, and the inserted sequence exhibited 98% identity with the avian leukosis virus ev-1 sequence. In comparison, brindle and normal chickens had the homozygous color genotype, and their sequences were the same as the wild-type sequence, indicating that this phenotype is derived from other mutation(s). In conclusion, white chickens have a recessive white mutation allele. Since the size of the sample used in this study was limited, further research through securing additional samples to perform validation studies is necessary. Therefore, after validation studies, a selection system for conserving the phenotypic characteristics and genetic diversity of the population could be established if additional studies to elucidate specific phenotype-related genes in Yeonsan Ogye are performed.

• Journal of Genetic Medicine
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• v.15 no.1
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• pp.24-27
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• 2018

Cornelia de Lange syndrome (CdLS) is a rare, clinically and genetically heterogeneous, multi-system developmental disorder caused by mutations in genes that encode components of the cohesin complex. X-linked CdLS caused by an SMC1A mutation is an extremely rare disease characterized by phenotypes milder than those of classic CdLS. In the Republic of Korea, based on a literature review, one family with SMC1A-related CdLS with mild phenotypes has been genetically confirmed to date. In this study, we describe the clinical features of a Korean boy with a hemizygous novel missense mutation and his mother with a heterozygous mutation, i.e., c.2447G>A (p.Arg816His) in SMC1A, identified by multi-gene panel sequencing. The proband had a mild phenotype with typical facial features and his mother exhibited a mild, subclinical phenotype. This study expands the clinical spectrum of patients with X-linked CdLS caused by SMC1A variants. Moreover, these findings reinforce the notion that a dominant negative effect in a carrier female with a heterozygous mutation in SMC1A results in a phenotype milder than that in a male patient with the same mutation.

• Korean Journal of Veterinary Service
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• v.35 no.2
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• pp.99-104
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• 2012

Otitis externa (OE) is a frequent disease in the ear canals of dogs. To identify the pathogens causing OE in dogs and to determine their antimicrobial resistances, specimens were collected from animal hospitals in Daejeon. The isolates were examined by morphological and biochemical tests, 16S rRNA analysis and antimicrobial susceptibility tests. We analyzed correlation between the isolated pathogens and external factors of dogs such as breed, age, gender, ear mite, hair in ears and experience with antibiotic therapy. Thirty three strains of bacteria were isolated from 26 of the 68 heads of dogs with OE. The most isolated bacteria were Enterococcus faecalis (E. faecalis) followed by Staphylococcus aureus (Sta. aureus), Sta. pseudointermedius, E. faecium, E. avium and Streptococcus canis (Strep. canis) in order of frequency of occurrence. Isolation frequency of Enterococcus spp. and Staphylococcus spp. were 51.5% and 45.5%, respectively. E. faecalis and E. faecium isolates showed VanB phenotype, which is resistant to vancomycin but sensitive to teicoplanin were 58% and 25%, respectively. Nine isolates among total twelve isolates of E. faecalis were isolated from the dogs treated with antibiotics. There was no methicillin-resistant Sta. aureus (MRSA), but were MR-Sta. pseudointermedius (MRSP) (57.1%) and vancomycin-resistant (VR)-Sta. pseudointermedius (14.3%) (VRSP) showing VanB phenotype. However, vanA, vanB and vanC genes were not detected in VR isolates from the dogs. Taken together, VR-Enterococcus spp. (VRE) is one of the major pathogens in domestic animals, as well as community-and hospital-acquired infection.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.2
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• pp.285-294
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• 1992

Biochemical polymorphisms of sow's milk proteins, $\beta$-casein ($\beta$-CN), $\beta$-lactoglobulin ($\beta$-LG), post-lactoglobulin (post-LG), $\alpha$-lactalbumin ($\alpha$-LA) and X-protein, as genetic markers for major pig breeds (Landrace, Yorkshire, Duroc, Hampshire and cross bred) in Korea were determined by starch gel electrophoresis. Phenotype and gene frequencies at all marker loci were estimated and genetic differences among breed populations were analyzed. Three $\beta$-CN phenotypes (AA, AB and BB) controlled by two codominant alleles (${\beta}-CN^A$ and ${\beta}-CN^B$), four $\beta$-LG phenotypes (AA, AC, $AC^{\pm}$ and CC) controlled by two codominant alleles (${\beta}-LG^A$ and ${\beta}-LG^C$) and ten X-protein phenotypes (AA, BB, CC, DD, AB, AC, AD, BC, BD and CD) controlled by four codominant alleles ($X^A,\;X^B,\;X^C\;and\;X^D$) were identified. In addition, a genetically controlled polymorphism of post-LG was found for the first time in sow's milk protein. Three different phenotypes (AA, AB and BB) were designated $post-LG^A$ and $post-LG^B$. Of the five marker loci examined, $\alpha$-LA locus was observed to lack any individual variation in all breeds studied. All populations were in Hardy-Weinberg equilibrium for all loci. There were marked breed differences for phenotype and gene frequencies in the post-LG and X-protein marker loci. However, there were little differences between breeds in the gene frequencies at the $\beta$-CN and $\beta$-LG marker loci.

• Journal of Life Science
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• v.31 no.1
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• pp.28-36
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• 2021

Edwardsiella piscicida is a significant cause of hemorrhagic septicemia in fish and gastrointestinal infections in humans. Survival bacteria require specialized mechanisms to adapt to environmental fluctuations. Hence, to understand the mechanism through which E. piscicida senses and responds to environmental osmolarity changes, we determined the protein expression profile and physiological properties under various salinity conditions in this study. The OmpR protein is a part of the Env-ZOmpR two-component system that has been implicated in sensing salt stress in bacteria. However, the physiological role played by this protein in E. piscicida remains to be elucidated. Therefore, in this work, the function of the OmpR protein in response to salt stress was investigated. Phenotypic analysis revealed that, in the mutant, three of the biochemical phenotypes were different from the wild type, including, citrate utilization, hydrogen sulfide, and indole production. Introduction of the plasmid containing the entire ompR gene to the mutant strain returned it to its parental phenotype. The retarded growth rate also partially recovered. Furthermore, in our studies, OmpR was not found to be related to cell motility. Taken together, our results from the mutational analysis, the growth assay, MALDI-TOF MS, qRT-PCR, and the phenotype studies suggest that the OmpR of E. piscicida is implicated in osmoregulation, growth, expression of porins (ETAE_1826), virulence-related genes (EseC, EseD and EvpC), and certain genes of unknown function (ETAE_1540 and ETAE_2706).

• Journal of Veterinary Clinics
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• v.8 no.1
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• pp.27-30
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• 1991

Transferrin type of stallions and their foals in total of 56 was analysed. Phenotype showed 8 types(AA, AB, AC, AD, AE, BB, BC, BD), while gene frequencies A ; 0.410, B ; 0.455, C : 0.063, D ; 0.063, E ; 0.09 There were not negative factors in the result of idenification of real paternity but showed AC type that is abscent in their parents.

• Clinical and Experimental Pediatrics
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• v.52 no.6
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• pp.680-688
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• 2009

Purpose : Cysteinyl leukotrienes are important proinflammatory mediators in asthma. Recently, it was suggested that a promoter polymorphism in the genes encoding for leukotriene C4 synthase (LTC4S), a key enzyme in the leukotriene synthetic pathway, and cysteinyl leukotriene receptor 1 (CysLTR1) might be associated with aspirin-intolerant asthma. We investigated whether polymorphisms in LTC4S and CysLTR1 genes or their interactions were associated with the asthma phenotype, lung function, or bronchial hyperreactivity (BHR) in Korean children. Methods : A total of 856 asthmatic children and 254 non-asthmatic controls were enrolled; a skin prick test, lung function test and bronchial provocation test were performed. Of those enrolled, 395 children underwent exercise challenge tests. The LTC4S A(-444)C and CysLTR1 T(＋927)C were genotyped by polymerase chain reaction-restriction fragment length polymorphism analysis. Results : Of those enrolled, 699 children were classified as having atopic asthma and 277 children, as having exercise-induced asthma (EIA). LTC4S and CysLTR1 polymorphisms were not associated with atopic asthma, EIA, or asthma per se. Lung function and BHR were not significantly different between the wild type (AA or TT) and the variant (AC＋CC or TC＋CC) genotypes in asthmatics, atopic asthmatics, and EIA (＋) asthmatics, while total eosinophil counts were higher in the variant type of LTC4S than in the wild type in atopic asthmatics. There were no associations between the gene-gene interactions of LTC4S and CysLTR1 genotypes and the asthma phenotypes. Conclusion : LTC4S A(-444)C and CysLTR1 T(＋927)C polymorphisms and their gene-gene interactions are not associated with asthma phenotype, lung function, or BHR in Korean children.

• Korean Journal of Microbiology
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• v.22 no.4
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• pp.229-234
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• 1984

A modified E. coli trp operon, $trpL({\Delta}att)\;trpE^{FBR}$, was conjugally transfered into Klebsiella pneumoniae $KC_{100}\;(Phe^-,\;Tyr^-,\;Trp^-,\;Rif^r,\;Kam^r)$ by in vivo cloning using the hybrid plasmid $R_{6}K::$ Mucts 61 with a transfer frequency of $5.2{\times}10^{-7}$. Two K. pneumoniae transconjugants, $KUA_{701}\;and\;KUA_{702}$, were isolated. The characters of attenuation control-free and resistance to feedback-inhibition which are characteristics of donor C. coli trp operon were normally expressed in the $KUA_{701}.\;However,\;KUA_{702}$ retained only the feedback-inhibition resistant character. $Trp^+$ phenotype and ampicillin resistant character were completely stable in the transconjugants, but streptomycin resistant character was lost in the transconjugants.

• The Journal of Natural Sciences
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• v.11 no.1
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• pp.65-73
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• 1999

C-P compounds(Pn; phosphonate) such as glyphosate(GPS), aminoethylphosphonate(AEPn) and methyl-phosphonate(MPn) biodegrading genes were cloned from Pseudomonas sp. strain #A1 Which assimilated GPS as sole phosphorous source. Carrying out the in vivo molecular cloning by means of Mini-Mu plasmid, the size of clones($AEPn^+$, $MPn^+$, $GPS^+$) for the gene to degrade C=P compounds are 10-19Kb, 10Kb, and 12-18 Kb, respectively. Moreover, they expressed the phenotype for each Pn when they were transformed into $\Delta phn$ mutants. Hence, it is postulated that Pseudomonas sp.#A1 has three kind of Pn degradative pathway, separately. The phn clones($AEPn^+$, $MPn^+$, $GPS^+$) are verified as the members of PHO regulon because of their phoBR-dependent characteristics.