• Asian-Australasian Journal of Animal Sciences
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• v.26 no.11
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• pp.1518-1522
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• 2013

TYR (Tyrosinase) and TYRP1 (Tyrosinase-related protein 1) play crucial roles in determining the coat color of birds. In this paper, we aimed to characterize the relationship of TYR and TYRP1 genes with plumage colors in Korean quails. The SNPs were searched by cDNA sequencing and PCR-SSCP in three plumage color Korean quails (maroon, white and black plumage). Two SNPs ($367T{\rightarrow}C$ and $1153C{\rightarrow}T$) were found in the coding region of TYRP1 gene, but had no significant association with plumage phenotype in Korean quails. The expression of TYR was higher in black plumage quails than that in maroon plumage quails. In contrast, the expression of TYRP1 was lower in black plumage quails than that in maroon plumage quails. This study suggested that the melanic plumage color in Korean quails may be associated with either increased production of TYR or decreased production of TYRP1.

• Asian-Australasian Journal of Animal Sciences
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• v.27 no.8
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• pp.1069-1074
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• 2014

In China and South East Asia, the duck (common duck) is important in egg production for human consumption. Plumage color is a breed characteristic and of economic importance, together with egg production. Our aim in this study was to investigate the inheritance of plumage color in three Chinese indigenous egg-type duck breeds, Shan Ma (S), Putian White (F) and Putian black (P), and some of their crossbreds. These three breeds have different plumage color and are used in crossbreeding. The crossbred laying ducks $F{\times}(P{\times}S)$ and $F{\times}(S{\times}P)$ showed highly improved laying ability but heterogeneous plumage color. Genotypes at four relevant loci were investigated by studying down color and pattern in ducklings after crossbreeding. $F_1$ ducklings from the matings $F{\times}S$ and $S{\times}F$, $P{\times}S$, and $S{\times}P$ were classified into four classes of plumage color (the Shan Ma plumage color, black, white, or multicolored) over three generations. Parents were selected for the Shan Ma plumage color of their progeny. In the fourth generation, P male and P female ducks were selected according to the frequency of the desired class of plumage color (Shan Ma) of their $F_1$ progeny to obtain the so-called "Brown Putian Ma duck". The Shan Ma duck genotype was identified as having the restricted mallard color pattern ($M^RM^R$), full expression of any of the patterns or colors (CC), no extended black (ee) and no brown dilution D (D). The Putian White genotype was recessive white (cc), no extended black (ee) and no brown dilution D (D). The Putian Black genotype exhibited full expression of extended black (E gene) and no brown dilution (CCEE D [D]). It was shown that $F{\times}S$ and $S{\times}F$ tests should be implemented to eliminate the recessive white c allele in the S line and the dominant extended black E allele in the F line. It was also shown that the Brown Putian Ma obtained from Putian Black, with no extended black genotype (ee), could be used to get rid of the black plumage (E gene) in the crossbred ducks. This could provide a solution for producing 3-way crossbred ducks Putian $White{\times}$(Putian-$Ma{\times}Shan$ Ma) and Putian $White{\times}$(Shan $Ma{\times}Putian$-Ma), with the desired Shan Ma feather color.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.11
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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.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.5
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• pp.625-629
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• 2013

The melanocortin 1 receptor (MC1R) gene is related to the plumage color variations in chicken. Initially, the MC1R gene from 30 individuals was sequenced and nine polymorphisms were obtained. Of these, three and six single nucleotide polymorphisms (SNPs) were confirmed as synonymous and nonsynonymous mutations, respectively. Among these, three selected SNPs were genotyped using the restriction fragment length polymorphism (RFLP) method in 150 individuals from five chicken breeds, which identified the plumage color responding alleles. The neighbor-joining phylogenetic tree using MC1R gene sequences indicated three well-differentiated different plumage pigmentations (eumelanin, pheomelanin and albino). Also, the genotype analyses indicated that the TT, AA and GG genotypes corresponded to the eumelanin, pheomelanin and albino plumage pigmentations at nucleotide positions 69, 376 and 427, respectively. In contrast, high allele frequencies with T, A and G alleles corresponded to black, red/yellow and white plumage color in 69, 376 and 427 nucleotide positions, respectively. Also, amino acids changes at position Asn23Asn, Val126Ile and Thr143Ala were observed in melanin synthesis with identified possible alleles, respectively. In addition, high haplotype frequencies in TGA, CGG and CAA haplotypes were well discriminated based on the plumage pigmentation in chicken breeds. The results obtained in this study can be used for designing proper breeding and conservation strategies for the Korean native chicken breeds, as well as for the developing breed identification markers in chicken.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.2
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• pp.180-188
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• 2018

Objective: The aim of this study was to investigate the effect of single nucleotide polymorphisms (SNPs) of the melanogenesis associated transcription factor (MITF) and dopachrome tautomerase (DCT) genes on plumage coloration in Asian native duck breeds. MITF encodes a protein for microphthalmia-associated transcription factor, which regulates the development and function of melanocytes for pigmentation of skin, hair, and eyes. Among the tyrosinase-related family genes, DCT is a pigment cell-specific gene that plays important roles in the melanin synthesis pathway and the expression of skin, feather, and retina color. Methods: Five Asian duck varieties (black Korean native, white Korean native, commercial Peking, Nageswari, and Bangladeshi Deshi white ducks) were investigated to examine the polymorphisms associated with plumage colors. Among previously identified SNPs, three synonymous SNPs and one indel of MITF and nine SNPs in exon regions of DCT were genotyped. The allele frequencies for SNPs of the black and white plumage color populations were estimated and Fisher's exact test was conducted to assess the association between the allele frequencies of these two populations. Results: Two synonymous SNPs (c.114T>G and c.147T>C) and a 14-bp indel (GCTGCAAAC AGATG) in intron 7 of MITF were significantly associated with the black- and white-colored breeds (p<0.001). One non-synonymous SNP [c.938A>G (p.His313Arg)] in DCT, was highly significantly associated (p<0.001) and a synonymous SNP (c.753A>G) was significantly associated (p<0.05) with black and white color plumage in the studied duck populations. Conclusion: The results of this study provide a basis for further investigations of the associations between polymorphisms and plumage color phenotypes in Asian duck breeds.

• 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.

• Korean Journal of Poultry Science
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• v.44 no.2
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• pp.75-81
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• 2017

A total of 340 individuals from seven duck populations were studied using 24 polymorphic microsatellite (MS) markers to identify plumage colors with genetic diversity. The estimated average number of alleles (Na), polymorphic information content (PIC) value, and expected heterozygosity (He) per locus of all populations were 11.5, 0.602, and 0.635, respectively. The calculated population genetic distance (Fst), inbreeding coefficient of individuals within duck populations (Fis), and total inbreeding among populations (Fit) were 0.135, 0.105, and 0.229, respectively. Statistical analyses for each population using 24 marker combinations, revealed that the estimated average number of effective alleles (Ne), observed heterozygosity (Ho), and fixation index of inbreeding within populations (F) were 3.129, 0.505, and 0.104, respectively. The results of genetic distance and phylogenetic analysis revealed that Korean native duck populations were clearly separated from all Bangladeshi duck populations. Moreover, all populations clustered well according to their genetic distance, but could not be clearly separated according to black and white plumage colors or plumage color pattern. The combination of these 24 MS markers can be used for discrimination and determination of the genetic diversity of native duck breeds in further investigations for conservation and special development purposes.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.10
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• pp.1372-1381
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• 2017

Objective: Our study provides information on phenotypes of local chickens and guinea fowl and their body measures as well as on major genes in local chickens in northern Ghana. Methods: Qualitative and morphometric traits were recorded on 788 local chickens and 394 guinea fowl in urban households in Tamale, Ghana. Results: The results showed considerable variation of color traits and numerous major genes in local chickens, while color variations and related genotypes in guinea fowl were limited. In local chickens, white was preferred for plumage, whereas dark colors were preferred for beak and shanks. More than half of the chickens carried at least one major gene, but the contributions of single gene carriers were low. All calculated allele frequencies were significantly lower than their expected Mendelian allele frequencies. We observed higher mean body weight and larger linear body measures in male as compared to female chickens. In female chickens, we detected a small effect of major genes on body weight and chest circumference. In addition, we found some association between feather type and plumage color. In guinea fowl, seven distinct plumage colors were observed, of which pearl grey pied and pearl grey were the most prevalent. Male pearl grey pied guinea fowl were inferior to pearl grey and white guinea fowl in terms of body weight, body length and chest circumference; their shank length was lower than that of pearl grey fowl. Conclusion: Considerable variation in qualitative traits of local chickens may be indicative of genetic diversity within local chicken populations, but major genes were rare. In contrast, phenotypic and genetic diversity in local guinea fowl is limited. Broader genetic diversity studies and evaluation of trait preferences of local poultry producers are required for the design of appropriate breeding programs.

• Korean Journal of Poultry Science
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• v.12 no.2
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• pp.65-73
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• 1985

More than 1,000 chickens of Korean native Yeonsan Ogolgye (Natural Monument No. 256) were used in this study in order to investigate their various external characteristics. The aims of this study were to define the Ogolgye chicken as a breed, and to provide basal data necessary for the genetic improvement of this breed. The investigated items are as follows : color of feather and toe; presense or absence of shank feather; the number of toes: color of shank and comb; the growth rates of shank, comb and feathers in various feather tracts; and finally, the livability. Data and informations were presented in tabular form in table 1 through 12. In summary, the various external traits of the Korean native Ogolgye breed can be characterized as follows. It has normal feather than silkic one as in the western type, with black color per-dominant. The frquency of white feather color is very low. The color of toes is devided into two categories; black toes in black plumage lines, and white toes in white plumage lines. Both seres have single combs with black color. The shank is gray- black and featherless. The breed has normally four toes. The eye color is black.

• Korean Journal of Poultry Science
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• v.49 no.3
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• pp.157-165
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• 2022

Chickens are a species of vertebrate with varying colors. Various colors of chickens must be classified to find color-related genes. In the past, color scoring was performed based on human visual observation. Therefore, chicken colors have not been measured with precise standards. In order to solve this problem, a computer vision approach was used in this study. Image quantization based on k-means clustering for all pixels of RGB values can objectively distinguish inherited colors that are expressed in various ways. This study was also conducted to determine whether plumage color differences exist in the reciprocal cross lines between two breeds: black Yeonsan Ogye (YO) and White Leghorn (WL). Line B is a crossbred line between YO males and WL females while Line L is a reciprocal crossbred line between WL males and YO females. One male and ten females were selected for each F₁ line, and full-sib mating was conducted to generate 883 F₂ birds. The results indicate that the distribution of light and dark colors of k-means clustering converged to 7:3. Additionally, the color of Line B was lighter than that of Line L (P<0.01). This study suggests that the genes underlying plumage colors can be identified using quantification values from the computer vision approach described in this study.