• Proceedings of the Korea Society of Poultry Science Conference
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• 2004.11a
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• pp.13-15
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• 2004

Telomeres are the end of chromosomes and consist of a tandem repeat sequence of (TTAGGG)n and associated proteins. Telomeres are essential for chromosome stability and are related with cell senescence and apoptosis. This study was carried out to analyze the amount of telomeric DNA of chicken lymphocytes, which is to considered as bio-marker. The amount of telomeric DNA of lymphocytes in Korean Native Chicken and White Leghorn was analyzed by quantitative-fluorescence in situ hybridization (Q-FISH) technique using the chicken telomeric DNA probe. Telomere quantifies were compared among breeds, ages and sex, and the relationship between the amount of telomeres and their productive trait was also analyzed. Comparing the amount of telomeric DNA on lymphocytes during growing period, the amount of telomeres was gradually decreased as growing older. The telomere quantity was also significantly different in breeds and sex. Estimating correlation coefficient, the amount of telomeres was positively correlated to sexual maturity and body weight but negatively correlated to hen day egg production and egg weight. These results implicate the telomere quantity is considered as an individual bio-marker.

• Korean Journal of Poultry Science
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• v.44 no.1
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• pp.1-9
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• 2017

The objective of the present study was to determine the expression of genes associated with lipopolysaccharide (LPS)-induced stressor in two breeds of chickens: the Korean native chicken (KNC) and the White Leghorn chicken (WLH). Forty chickens per breed, aged 40 weeks, were randomly allotted to the control (CON, administered the saline vehicle) and LPS-injected stress groups. Samples were collected at 0 and 48 h post-LPS injection, and total RNA was extracted from the chicken livers for RNA microarray and quantitative real-time polymerase chain reaction (qRT-PCR) analyses. In response to LPS, 1,044 and 1,193 genes were upregulated, and 1,000 and 1,072 genes were downregulated in the KNC and WLH, respectively, using a ${\geq}2$-fold cutoff change. A functional network analysis revealed that stress-related genes were downregulated in both KNC and WLH after LPS infection. The results obtained from the qRT-PCR analysis of mRNA expression of heat shock 90 (HSP90), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), activating transcription factor 4 (ATF4), sterol regulatory element-binding protein 1 (SREBP1), and X-box binding protein 1 (XBP1) were confirmed by the results of the microarray analysis. There was a significant difference in the expression of stress-associated genes between the control and LPS-injected KNC and WLH groups. The qRT-PCR analysis revealed that the stress-related $HSP90{\alpha}$ and HMGCR genes were downregulated in both LPS-injected KNC and WLH groups. However, the HSP70 and $HSP90{\beta}$ genes were upregulated only in the LPS-injected KNC group. The results suggest that the mRNA expression of stress-related genes is differentially affected by LPS stimulation, and some of the responses varied with the chicken breed. A better understanding of the LPS-induced infective stressors in chicken using the qRT-PCR and RNA microarray analyses may contribute to improving animal welfare and husbandry practices.

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.964-970
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• 1999

Fatty acid composition and sensory characteristics of six commercial chickens(CC-RcDR, RcLR, BcBR, BcDR, BcLR, RcBR), one broiler(Arbor Acre) and three Korean native chickens(KNC-D, L, B) were evaluated. In the fatty acid composition at marketing age, KNC had generally higher unsaturated fatty acid ratio than the others. B, BcBR and BcDR showed the highest in unsaturated fatty acid but the lower than others in saturated fatty acid composition. The results of sensory test showed significant difference(P<0.05) only in the leg. B and RcBR had the highest score and Arbor Acre lowest score in juiciness. In tenderness. B had the highest score and RcDR lowest score. In the case of acceptability, KNC generally had high score. Particularly B had the highest score. Among CC, RcBR had the highest score. There were no significant differences in flavor and aroma.

• Korean Journal of Poultry Science
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• v.33 no.2
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• pp.97-103
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• 2006

Telomeres are essential for chromosome stability and are related with cell senescence, apoptosis and cancer. Even though telomere length and telomerase activity have been studied extensively, very little is known to analyze the telomere dynamics in chicken cells. This study was carried out to analyze the telomere distribution and telomerase activity of Korean Native Chicken cells along with aging. The cells were collected from brain, heart, liver, kidney and germinal tissues during physiological stages. Telomere distribution was analyzed by Quantitative-Fluorescence in situ Hybridization (Q-FISH) techniques using the chicken telomeric DNA probe. Telomerase activity was performed by Telomeric Repeat Amplification Protocol (TRAP) assay. In results, the telomeres of chicken were found at the ends of all chromosomes with the interstitial telomeres on chromosomes 1, 2 and 3. The amount of telomeres on chicken cells was decreased along with aging in most tissues. Furthermore, the telomere quantity was significantly different among tissues. The relative amount of telomeres in proliferous cells such as testis cells had much more than those of liver, brain, heart, blood and kidney cells. The telomerase activity was down-regulated in cells of brain, heart and liver tissues. Whereas gonadal cells showed a constitutive activity of telomerase during all stage of life. In conclusions, the telomere quantity and telomerase activity in chicken are closely relate to cell proliferation and tissue specificity during developmental stages and aging. There is also closely correlated between the amounts of telomeric DNA and telomerase activity in chicken tissues.

• Korean Journal of Poultry Science
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• v.40 no.2
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• pp.115-120
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• 2013

Thyroid hormone (TH) plays a role in growth of the poultry. Thyroid-stimulating hormone (TSH) stimulates production and distribution of TH, and is a heterodimer which is formed by ${\alpha}$- and ${\beta}$-subunits. Most of TSH activity is known to rely on ${\beta}$-subunit. TSH-${\beta}$ gene is located on chicken chromosome 26 and associated with growth performances. Therefore, this study aimed to investigate the association of TSH- ${\beta}$ SNP (G1031C) with economic traits (layday, layw, layno, bw150, bw270, layw270) in Korean Native Black chicken, Rhode Island Red and Cornish. Allele frequency of GG genotype in Rhode Island Red (RIR) was found to be 1.00 in this study. A significant effect was only observed on body weight at day 150 in Cornish. In Cornish, body weights of chicken with the CC genotype ($302.15{\pm}6.336$) were significantly higher than that of the GG genotype ($294.56{\pm}4.537$) (p<0.05). These findings suggest that the G1031C SNP of TSH-${\beta}$ gene can be used for improvement of growth-related traits in Cornish.

• Korean Journal of Poultry Science
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• v.27 no.1
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• pp.79-84
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• 2000

This study was carried out to investigate the characteristics of semen and egg storage period on hatchability of Korean native chicken(KNC, 44-wk old). The body weight, volume of semen, concentration of spermatozoa, total sperm of an ejaculate, motility of sperm and percentage of fertile eggs were 2,555.89g, 0.473$m\ell$, 30.81${\times}$10(sup)8/$m\ell$, 13.14${\times}$10(sup)8 cells, 3.58 and 91.69%, respectively, in KNC. The percentage of fertile eggs were 87.9∼96.0% on storage period in KNC. The viability and hatchability were 80.2%. 74.6%, respectively, in storage period for 22 days in storage temperature of 11∼14$^{\circ}C$. The results of the trial show that viability can be get more than 80% in storage period for 3 weeks in storage temperature of about 13$^{\circ}C$.

• Korean Journal of Poultry Science
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• v.25 no.2
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• pp.65-70
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• 1998

A 16-wk feeding trial was conducted to investigate the proper feeding regimen on the performance of Korean Native Chicken(KNC) consuming broiler diets. Commercial KNC are normally fed 3 kinds of diets during their life span, i. e., starter(S, 0 to 3wk of age), grower(G, 4 to 7wk of age), and finisher(F, 8 to l6wk of age) diets. In this trial, four feeding regimen were employed:T1(S-G-F), T2(S-G-G), T3(S-S-F), and T4(S-F-F). Day-old 360 KNC were randomly allotted to 12 pens: three pens per treatment, and 30 birds per pen. At the end of the trial, the BW of T2 was significantly better than that of T3(P<0.05), and T1 and T4 were intermediate. No significant difference were found in feed intake, feed conversion ratio, and viability among treatments. It appears that, in terms of BW gain, the T2 is the recommendable feeding regimen for KNC consuming broiler diets.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2003.11a
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• pp.129-130
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• 2003

There is growing interest for improving meat quality in chicken. Recently, the proteomics can be used as a valuable tool for identifying candidate proteins. In this study, we investigated the proteins expressed in chicken muscle for obtaining chicken muscle reference two dimensional(2D) map and identifying the proteins in muscle affecting Ginseng diet. A few candidate proteins have been currently characterizing using MALDI-TOF Mass spectrometry. Further investigations of the proteins can be used as valuable markers for selection of better quality chicken meat.

• Korean Journal of Poultry Science
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• v.36 no.4
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• pp.323-328
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• 2009

In order to determine the origin and genetic diversity among chicken breeds, mitochondrial (mt) DNA D-loop sequences have been widely used. In this study, 41 individuals from four breeds (Korean native chicken (Black and Brown) and two imported breeds, Rhode Island Red and Cornish) were used for identifying genetic relationships with other chicken breeds. We obtained ten haplotypes and the highest number of haplotype was represented by eight individuals each from haplotype 1 and haplotype 2. Neighbor-joining phylogenetic tree indicates that the black and brown Korean native chicken breeds were mixed in haplotype 2 and they were closely related with the red jungle fowl (Gallus gallus). We also investigated whether the D-loop hypervariable region in chicken mtDNA can be used for the breed identification marker. The results indicated that the combination of the SNPs in the D-loop region can be possibly used for the breed discriminating markers. The results obtained in this study can be used for designing proper breeding and conservation strategies for Korean native chicken, as well as development of breed identification markers.

• Korean Journal of Poultry Science
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• v.40 no.3
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• pp.263-270
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• 2013

The vent sexing and the auto-sexing by using sex-linked traits are general sexing methods of day-old chicks. Currently, the feather sexing which is based on the differences in the feather characteristics at hatching is the representative sexing method of chicken, because the late-feathering is sex-linked trait. The feather sexing can be used if the breed has dominant feathering gene (K) in maternal and recessive gene ($k^+$) in paternal. Therefore it is necessary to identify the association of feathering genes and quantitative traits in chickens. In this study, we investigated the influence of the rate of feathering on productive traits in Korean Native Chicken. In results, there was no significant difference between early-feathering chickens and late-feathering chickens in reproductive performance such as fertility and hatchability. Livability, body weights, egg production, egg weight and egg quality also did not significantly differ between early- and late-feathering chickens. Age at first egg was the only trait of those tested in which significant difference was observed. The early-feathering chickens laid eggs 3 days earlier than late-feathering chicken. As a result, there is no influence of feathering phenotypes on productive performance in Korean Native Chickens. Consequentially, establishing the feather sexing strain is available using the Korean Native Chicken breed without considering of the effect of feathering genes on productive traits.