• Asian-Australasian Journal of Animal Sciences
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• 제32권1호
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• pp.49-57
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• 2019

Objective: The first stage in both breeding and programs for the conservation of genetic resources are the identification of genetic diversity in the relevant population. The aim of the present study is to identify genetic diversity of six brown layer pure chicken lines (Rhode Island Red [RIRI, RIRII], Barred Rock [BARI, BARII], Columbian Rock [COL], and line 54 [L-54]) with microsatellite markers. Furthermore, the study aims to employ its findings to discuss the possibilities for the conservation and sustainable use of these lines that have been bred as closed populations for a long time. Methods: In the present study, a total number of 180 samples belonging to RIRI (n = 30), RIRII (n = 30), BARI (n = 30), BARII (n = 30), L-54 (n = 30), and COL (n = 30) lines were genotyped using 22 microsatellite loci. Microsatellite markers are extremely useful tools in the identification of genetic diversity since they are distributed throughout the eukaryotic genome in multitudes, demonstrate co-dominant inheritance and they feature a high rate of polymorphism and repeatability. Results: In this study, we found all loci to be polymorphic and identified the average number of alleles per locus to be in the range between 4.41 (BARI) and 5.45 (RIRI); the observed heterozygosity to be in the range between 0.31 (RIRII) and 0.50 (BARII); and $F_{IS}$ (inbreeding coefficient) values in the range between 0.16 (L-54) and 0.46 (RIRII). The $F_{IS}$ values obtained in this context points out to a deviation from Hardy-Weinberg equilibrium due to heterozygote deficiency in six different populations. The Neighbour-Joining tree, Factorial Correspondence Analysis and STRUCTURE clustering analyzes showed that six brown layer lines were separated according to their genetic origins. Conclusion: The results obtained from the study indicate a medium level of genetic diversity, high level inbreeding in chicken lines and high level genetic differentiation between chicken lines.

• Asian-Australasian Journal of Animal Sciences
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• 제29권9호
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• pp.1256-1264
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• 2016

Adrenergic, alpha-1B-, receptor (ADRA1B) and peroxisome proliferator-activated receptor gamma, coactivator 1 beta (PPARGC1B) genes are involved in regulation of hen ovarian development. In this study, these two genes were investigated as possible molecular markers associated with hen-housed egg production, egg weight (EW) and body weight in Chinese Dagu hens. Samples were analyzed using the polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) technique, followed by sequencing analysis. Two novel single nucleotide polymorphisms (SNPs) were identified within the candidate genes. Among them, an A/G transition at base position 1915 in exon 2 of ADRA1B gene and a T/C mutation at base position 6146 in the 3'- untranslated region (UTR) of PPARGC1B gene were found to be polymorphic and named SNP A1915G and T6146C, respectively. The SNP A1915G (ADRA1B) leads to a non-synonymous substitution (aspartic acid 489-to-glycine). The 360 birds from the Dagu population were divided into genotypes AA and AG, allele A was found to be present at a higher frequency. Furthermore, the AG genotype correlated with significantly higher hen-housed egg production (HHEP) at 30, 43, 57, and 66 wks of age and with a higher EW at 30 and 43 wks (p<0.05). For the SNP T6146C (PPARGC1B), the hens were typed into TT and TC genotypes, with the T allele shown to be dominant. The TC genotype was also markedly correlated with higher HHEP at 57 and 66 wks of age and EW at 30 and 43 wks (p<0.05). Moreover, four haplotypes were reconstructed based on these two SNPs, with the AGTC haplotype found to be associated with the highest HHEP at 30 to 66 wks of age and with higher EW at 30 and 43 wks (p<0.05). Collectively, the two SNPs identified in this study might be used as potential genetic molecular markers favorable in the improvement of egg productivity in chicken breeding.

• 한국가금학회지
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• 제42권4호
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• pp.315-325
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• 2015

최근 소비자의 소득 수준이 향상되고, 육제품의 다원화 성향이 증가하면서 가축개량은 과거 성장 및 육량 중심의 개량에서 품질 중심의 개량으로 중심이 이동하고 있다. 특히, 식육의 품질 중에서 육색은 소비자가 식육을 선택 및 질을 판단하는 기준으로 작용하기 때문에 매우 중요한 형질이라고 볼 수 있다. 경제적으로 유용한 형질은 대부분 측정가능한 연속변이에 해당하고, 이러한 형질은 대부분 여러 유전자가 형질에 영향을 미치는 양적형질 좌위(Quantitative Trait Loci;QTL)에 속한다. Chicken QTL db에 보고된 닭의 육색형질과 관련된 형질들은 육색(Bco, Mco), 가열감량(DL), pH가 보고되어 있으며, 이는 닭의 13개 염색체에서 33개 QTL 및 association 영역이 보고되고 있다. 이 중에서 육색관련 후보 유전자는 APP, BCMO1, COL1A2, FTO, KPNA2, PSMD12, G0S2, FTSJ3가 있으며, 가열감량관련 후보유전자는 AGRP, FTO, pH와 관련된 후보유전자는 GALNT1, PCDH19, DIAPH1, SPP2 유전자로 총 14개 유전자가 확인되었다. 이렇게 확인된 후보유전자 및 QTL 연구결과는 한국재래닭에 적용 및 활용 가능성을 확인해 볼 필요가 있으며, 이러한 적용은 낮은 성장속도의 단점을 가진 한국재래닭의 개발에 있어 품질의 개량속도를 높여 산업적 가치를 빠르게 끌어올릴 수 있는 중요한 표지인자가 될 수 있을 것으로 사료된다.

• 한국식품과학회지
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• 제33권5호
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• pp.582-588
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• 2001

단체급식용으로 납품되는 생계육에서 Salmonella를 분리하여 생육제어를 위한 생리특성을 분석하였다. 계육의 총균수는 표피의 내부 살부위에서도 표피 균수의 약 10%정도가 검출되었으며 75 개 계육시료로부터 선택배지를 사용하여 분리한 후 최종적으로 51 주의 Salmonella를 동정하였다. 이들 균주 중 약 70%의 Salmonella는 4종 이상의 항생제에 내성을 보이는 다제내성균으로 보여 국내에서의 기 분리균에 비해서 높은 비율의 항생제에 대한 내성을 나타내었다. 이들 Salmonella에 대한 여러 가지 위생처리제인 유기산의 중 lactic acid와 trisodium phosphate를 agar disk diffusion으로 표준균주인 S. typhimurium ATCC 14028, S. typhimurium ATCC 12023, S. heidelberg and S. enteritidis(isolated from egg)와 비교하였다. Lactic acid는 분리된 Salmonella나 표준균주 모두 비슷한 정도의 내성을 보여 주었고 오히려 분리 Salmonella는 더 내성이 적었다. 그러나 최근에 중요시되는 trisodium phosphate에는 표준균주에 비하여 분리된 wild type에서 내성이 강한 균주가 거의 절반에 가까운 정도로 많음을 알 수가 있었다. 또한 trisodium phosphate에 대한 내성은 처리시간과 처리 후 재생배지에 따라 다르게 보여서 이들은 환경에 따 라 내성이 다르게 나타난다는 것을 알았다. 계육에 오염된 Salmonella는 wild type이므로 실제 위생처리제로 사용할 때는 좀더 철저한 처리가 요망되었다. 그러므로 집단 급식소에 납품되는 계육은 브로일러 사육단계에서의 항생제 관리와 도계과정으로부터 세균오염을 줄여야 하는 노력과 함께 이러한 식중독균의 제어를 위한 위생처리제에 대한 지속적인 기술개발도 필요할 것이다.

• 한국가금학회지
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• 제25권3호
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• pp.103-111
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• 1998

This study was carried out to estirnate the heritabilities and genetic correlations on egg shape index and internal egg qualities ; shell thickness, alburnin heights and Haugh units for breeding plan and selection in Korean native chicken. Data analyzed were the records of 46,908 eggs from 43() layers from April, 1994 to September, 1995. The egg shape index at the first egg, 300 days and 500 days of ages were 74.771, 74.468 and 73.702; the shell thickness were 0.345, 0.344 and 0. 334mm; the alburnen heights were 6.579, 6.130 and 5.318mm; the Haugh units were 86.859, 81.014 and 73.565 respectively. The heritability estimates of egg shape index and internal egg qualities based on the variance of sire, dam and combined components at 300 days of age were 0.136, 0.954 and 0.545 for egg shape index; 0.201, 0.622 and 0.421 for shell thickness; 0.410, 0.961 and 0.633 for albumen height ; 0.353, 0.962 and': 0.608 for Haugh units. The genetic correlation coefficient between shell thickness and albumen height was -0.044~0.824; 0.016~0.949 between Haugh units and shell thickness 0.313~0.941 between albumen height and Haugh units, respectively.

• 한국가금학회지
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• 제40권3호
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• pp.223-234
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• 2013

Poultry industry is abounding day by day as it engrosses less cost of investment per bird as compared to large animals. Poultry have the most copious genomic tool box amongst domestic animals for the detection of quantitative trait loci (QTL) and marker assisted selection (MAS). Use of multiple markers and least square techniques for mapping of QTL affecting quality and production traits in poultry is in vogue. Examples of genetic tests that are available to or used in industry programs are documented and classified into causative mutations (direct markers), linked markers in population-wide linkage disequilibrium (LD) with the QTL (LD markers), and linked markers in population wide equilibrium with the QTL (LE markers). Development of genome-wide SNP assays, role of 42 K, 60 K (Illumina) and 600 K (Affymetrix$^{(R)}$ Axim$^{(R)}$) SNP chip with next generation sequencing for identification of single nucleotide polymorphism (SNP) has been documented. Hybridization based, PCR based, DNA chip and sequencing based are the major segments of DNA markers which help in conducting of MAS in poultry. Economic index-marker assisted selection (EI-MAS) provides platform for simultaneous selection for production traits while giving due weightage to their marginal economic values by calculating predicted breeding value, using information on DNA markers which are normally associated with relevant QTL. Understanding of linkage equilibrium, linkage dis-equilibrium, relation between the markers and gene of interest are quite important for success of MAS. This kind of selection is the most useful tool in enhancing disease resistance by identifying candidate genes to improve the immune response. The application of marker assisted selection in selection procedures would help in improvement of economic traits in poultry.

• 한국가금학회지
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• 제36권4호
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• pp.323-328
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• 2009

닭의 품종 기원을 결정하거나 유전적 변이의 정도를 확인 하는데 미토콘드리아 DNA D-loop 염기서열을 이용하여 오고 있다. 본 연구는 한국재래계 갈색종과 흑색종, 로드아일랜드레드종, 코니쉬종의 4품종 41개체의 염기서열을 분석함으로 품종간의 유전적 연관관계를 확인하였다. 그 결과 총 10개의 haplotype를 확인할 수 있었으며, haplotype 1과 2는 가장 많은 수인 8개체씩이 포함되었다. 계통도 분석을 통해 한국재래계 흑색종과 갈색종은 haplotype 2를 모두 가지고 있는 것으로 확인되었으며, 이 haplotype은 적색야계와 유전적으로 가깝게 위치한 것을 알 수 있었다. 본 연구를 통해 D-loop 염기서열 변이가 품종 판별 마커로 이용 가능성이 있는지 확인하였다. 그 결과 여러 단일염기다형 마커의 조합으로 품종의 구분이 가능할 것으로 추정되며, 앞으로 더 많은 연구가 진행되어야 할 것으로 생각된다. 이 연구의 결과는 한국재래계의 보존 및 육종계획 수립과 더불어 품종판별 마커의 개발의 기초 자료를 제공할 것으로 생각된다.

• Asian-Australasian Journal of Animal Sciences
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• 제26권11호
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• pp.1523-1528
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• 2013

To increase plumage color uniformity and understand the genetic background of Korean chickens, we performed a genome-wide association study of different plumage color in Korean native chickens. We analyzed 60K SNP chips on 279 chickens with GEMMA methods for GWAS and estimated the genetic heritability for plumage color. The estimated heritability suggests that plumage coloration is a polygenic trait. We found new loci associated with feather pigmentation at the genome-wide level and from the results infer that there are additional genetic effect for plumage color. The results will be used for selecting and breeding chicken for plumage color uniformity.

• 한국가금학회지
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• 제25권1호
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• pp.11-19
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• 1998

This study was conducted to estimate the heritabilities and genetic correlations on egg weight and egg compositional traits for breeding plan and selection in Korean native chicken. Data analyzed were the records of 46,908 eggs from 430 layers produced from 180 dam and 26 sire families, from April, 1994 to September, 1995. On egg weight and egg compositional traits at 1st egg, 300 and 500 days of age, the egg weights were 41.489, 49.544 and 52.770g ; the albumin weights were 25.953, 29.979 and 31.288g; the yolk weights were 11.091, 14.541 and 16.368g; shell weights were 4.472, 5.037 and 5.099g, respectively. The estimates of heritability of egg weights and egg compositional traits based on the variance of sires, dams and combined components at 300 days of age were 0.214, 0.226 and 0.720 for egg weight ; 0.307, 0.152 and 0.730 for albumin weight ; 0.124, 0.953 and 0.699 for yolk weight ; 0.047, 0.026 and 0.536 for shell weight. The genetic correlation coefficient between egg weight and albumen weight was 0.083~0.951 ; 0.310~0.507 between egg weight and yolk weight ; 0.242~0.523 between egg weight and shell weight ; 0. 237~0. 413 between albumen weight and yolk weight ; 0.232~0.449 between albumen weight and shell weight ; -0.264~0.239 between yolk weight and shell weight, respectively.

• 한국가금학회지
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• 제25권1호
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• pp.1-9
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• 1998

This study was carried out to get the basic and applicable data for breeding plan and selection in order to improve the body shape components in Korean native chicken. The hentabilities and genetic correlations on body shape components were estimated by sire, dam and combined components of variance. Data analyzed were records of 1,096 progenies produced from 180 dams and 26 sires from April, 1994 to September, 1995. On body shape components at 4, 8 and 16 weeks of age, the shank lengths were 55.63, 82.94 and 103.8Omm: breast girths were 15.087, 21.069, and 26.137mm: breast widths were 40.910, 54.575 and 73.088mm, respectively. The estimates of hentabilities of body shape components based on the variance of sires, dams, and combined components at 4, 8 and 16 weeks of age were O.O65~O.197, O.25O~O.794 and O.185~O.495 for shank length: O.123~O. 215, O.033~O.513 and 0.063~0.257 for breast girth; 0.024~0.158, 0.118~0.410 and 0.111~0.222 for breast width, respectively. The coefficients of genetic correlations among the body shape components at 4 weeks of age were 0.565, 0.725 and 0.678 for breast girth with breast width, shank length and tibia length : 0.690 and 0.804 for breast width with shank length and tibia length; 0.972 between shank length and tibia length.