Jaejung Ha

Identification of Stearoyl-CoA Desaturase (SCD) Gene Interactions in Korean Native Cattle Based on the Multifactor-dimensionality Reduction Method.

Fat quality is determined by the composition of fatty acids. Genetic relationships between this composition and single nucleotide polymorphisms (SNPs) in the stearoyl-CoA desaturase1 (SCD1) gene were examined using 513 Korean native cattle. Single and epistatic effects of 7 SNP genetic variations were investigated, and the multifactor dimensionality reduction (MDR) method was used to investigate gene interactions in terms of oleic acid (C18:1), mono-unsaturated fatty acids (MUFAs) and marbling score (MS). The g.6850+77 A>G and g.14047 C>T SNP interactions were identified as the statistically optimal combination (C18:1, MUFAs and MS permutation p-values were 0.000, 0.000 and 0.001 respectively) of two-way gene interactions. The interaction effects of g.6850+77 A>G, g.10213 T>C and g.14047 C>T reflected the highest training-balanced accuracy (63.76%, 64.70% and 61.85% respectively) and was better than the individual effects for C18:1, MUFAs and MS. In addition, the superior genotype groups were AATTCC, AGTTCC, GGTCCC, AGTCCT, GGCCCT and AGCCTT. These results suggest that the selected SNP combination of the SCD1 gene and superior genotype groups can provide useful inferences for the improvement of the fatty acid composition in Korean native cattle.

Identification of Exonic Nucleotide Variants of the Thyroid Hormone Responsive Protein Gene Associated with Carcass Traits and Fatty Acid Composition in Korean Cattle

The thyroid hormone responsive protein (THRSP) gene is a functional gene that can be used to indicate the fatty acid compositions. This study investigates the relationships of exonic single nucleotide polymorphisms (SNPs) in the THRSP gene and fatty acid composition of muscle fat and marbling score in the 612 Korean cattle. The relationships between fatty acid composition and eight SNPs in the THRSP gene (g.78 G>A, g.173 C>T, g.184 C>T, g.190 C>A, g.194 C>T, g.277 C>G, g.283 T>G and g.290 T>G) were investigated, and according to the results, two SNPs (g.78 G>A and g.184 C>T) in exon 1 were associated with fatty acid composition. The GG and CC genotypes of g.78 G>A and g.184 C>T had higher unsaturated fatty acid (UFA) and monounsaturated fatty acid (MUFA) content (p<0.05). In addition, the ht1*ht1 group (Val/Ala haplotype) in a linkage disequilibrium increased MUFAs and marbling scores for carcass traits (p<0.05). As a result, g.78 G>A and g.184 C>T had significantly relationships with UFAs and MUFAs. Two SNPs in the THRSP gene affected fatty acid composition, suggesting that GG and CC genotypes and the ht1*ht1 group (Val/Ala haplotype) can be markers to genetically improve the quality and flavor of beef.

Whole Genome Re-Sequencing of Three Domesticated Chicken Breeds.

Chicken is one of the most popular domesticated species worldwide, as it can serve an important role in agricultural as well as biomedical research fields. Because it inhabits almost every continent and presents diverse morphology and traits, the need of genetic markers for distinguishing each breed for various purposes has increased. The whole genome sequencing of three different breeds (White Leghorn, Korean domestic, and Araucana) that show similar coloring patterns, with the exception of the White Leghorn breed, have confirmed previously reported genomic alterations and identified many novel variants. Additionally, the Whole Genome Re-Sequencing (WGRS) approach identified an approximately 4 kb insert within SLCO1B3 responsible for blue egg shell color. Targeted investigation of pigment-related genes corroborated previously reported non-synonymous mutations, and provided deeper insight into chicken coloring, where not a single but a combination of non-synonymous mutations in the MC1R gene is likely to be responsible for altered feather coloring.

Whole genome sequencing of Gyeongbuk Araucana, a newly developed blue-egg laying chicken breed, reveals its origin and genetic characteristics.

Chicken, Gallus gallus, is a valuable species both as a food source and as a model organism for scientific research. Here, we sequenced the genome of Gyeongbuk Araucana, a rare chicken breed with unique phenotypic characteristics including flight ability, large body size, and laying blue-shelled eggs, to identify its genomic features. We generated genomes of Gyeongbuk Araucana, Leghorn, and Korean Native Chicken at a total of 33.5, 35.82, and 33.23 coverage depth, respectively. Along with the genomes of 12 Chinese breeds, we identified genomic variants of 16.3 million SNVs and 2.3 million InDels in mapped regions. Additionally, through assembly of unmapped reads and selective sweep, we identified candidate genes that fall into heart, vasculature and muscle development and body growth categories, which provided insight into Gyeongbuk Araucana’s phenotypic traits. Finally, genetic variation based on the transposable element insertion pattern was investigated to elucidate the features of transposable elements related to blue egg shell formation. This study presents results of the first genomic study on the Gyeongbuk Araucana breed; it has potential to serve as an invaluable resource for future research on the genomic characteristics of this chicken breed as well as others.

Detection of exonic variants within the melanocortin 1 receptor (MC1R) gene in Black Silky, White Leghorn and Golden duckwing Araucana chicken

ABSTRACTThe melanocortin 1 receptor (MC1R) gene can be considered a candidate functional gene for the pigmentation of plumage color. The aim of this study was to investigate the association between the genotype frequencies of g.69 T>C, g.376 G>A and g.427 A>G SNPs within the MC1R gene in Black silky (O), Golden duckwing Araucana (GA) and White Leghorn (W). The CC and AA genotype frequencies of g.69 T>C and g.427 A>G SNPs in White Leghorn (W) were both 1.000, and the TT genotype frequency of the g.69 T>C SNP in Golden duckwing Araucana (GA) was also 1.000. The GG and AA genotype frequencies of g.376 G>A and g.427 A>G SNPs in Black silky (O) were both 0.100. When a haplotype is observed using a combination of markers, a Golden duckwing Araucana (GA) can especially be distinguished when it is a TAG, TGG and TAA type in the SNP combination of the MC1R gene. In case of the CAA types, only White Leghorn (W) could specifically be distinguished. Therefore, three SNPs in MC1R may provide identification in chicken breeds.

Superior single nucleotide polymorphisms that contribute to two main routes of the fatty acid synthesis pathway in Korean cattle

The fatty acid composition of adipose tissue in livestock has been recognized as an important carcass trait that affects meat quality. To determine the overall positive effect on fatty acid synthesis, we investigated PPARγ, SREBPs, FABP4, SCD, and FASN genes because SNP and/or SNP combinations were strongly affecting each fatty acid synthesis pathway. We screened their SNPs, SNP combinations, and genotype. Furthermore, we studied the economic traits C18:1, monounsaturated fatty acid (MUFA), and marbling score (MS). To enhance the accuracy of the predictive genetic effect, we applied a statistical adjustment model excluding environmental factors. We also selected superior genes, gene combinations, and genotypes for each economic trait by using multifactor dimensionality reduction. Based on the results, g.3977-325 T>C (CC) was selected as the best genotype of the SNP and the combination (g.10153 A>G, g.3977-325 T>C) (AACC, AGCC, GGCC), (g.3690 G>A, g.3977-325 T>C) (GGCC, GACC), (g.3977-325 T>C, g.25670 C>T) (CCCC, CCCT, CCTT) (genotypes of the best SNP combination) was selected as the best gene combination for C18:1 and MUFA. In addition, g.3977-325 T>C (CC) was selected as the best genotype of the SNP and the combination (g.3977-325 T>C, g.6974 G>A) (TTAA, CTAA, CCAA, CCGA, CCGG) as the best SNP combination for MS. We integrated genes that were selected as excellent SNP and SNP combinations affecting two main routes of the fatty acid synthesis pathway and identified the best and final SNP, SNP combination, and superior genotype.

In vivo evidence on the functional variation within fatty acid synthase gene associated with lipid metabolism in bovine longissimus dorsi muscle tissue

In Korean cattle, intramuscular fat (IMF), or marbling, of the longissimus dorsi muscle (LM) cross section is one of the most important indicators of beef quality and are influenced by environmental and genetic factors. This study was to evaluate the effect of SNPs on the beef quality in Korean cattle for functional studies, such as site-directed mutagenesis based on bovine adipocytes. The fatty acid synthase (FASN) gene plays an important role in lipogenesis. FASN is an essential metabolic and multifunctional enzyme in fatty acid synthesis. Several studies have reported that SNPs g.841G, g.16024A, g.16039T, and g.17924G have a significant impact on marbling scores in Korean cattle and Japanese Black cattle population. These SNPs are located in transcription factor binding sites, the beta-ketoacyl reductase, and thioesterase domains. Our results revealed that the g.17924 A>G SNP is located in the thioesterase domain of the FASN protein, and changes from polar, neutral, and hydrophilic to nonpolar, aliphatic, and hydrophobic, respectively. In in vivo LM tissue of Korean cattle, the g.17924A>G SNP has an effect on increasing fat deposition. Therefore, g.17924A>G SNP could be a causal mutation for increasing fat deposition in Korean cattle LM tissue.

Rearing Characteristics of Fattening Hanwoo Steers Managed in Different Stocking Densities (R)

Objective This study was conducted to analyze the effects of stocking density on growth and carcass quality, and behavior of Hanwoo cattle to conform with global trends, targeting animal welfare production through the practice of environmentally friendly condition. Methods Thirty six steers were randomly assigned to three treatment groups (C: 5 heads, T1: 4 heads, T2: 3 heads) and reared in separate pens with a constant stocking density of 50 m2 (C: 10 m2/head, T1: 12.5 m2/head, T2: 16.67 m2/head) per group from 12 to 30 month of age. Growth performance, behavior and carcass quality traits of each steer were recorded and compared between the treatment groups. Results In general, the average daily gain during the fattening period was lower in group T2 than in T1 and the control groups. However, carcass weight and dressing percentage was lower in the control group than in T1 or T2 groups (p<0.05). Also, marbling score at 30 months of age was the lowest in the control group (p<0.05), while the three heads group (T2) had the greatest longissimus muscle area and marbling score (p<0.05). The behavior of walking time was the greatest in T2 group, while self-grooming and fighting occurred with the most frequency in the control group (p<0.05). Conclusion Our results show that the steers in more spacious stocking density had better carcass quality and wellbeing related behaviors, indicating that a lower density has a positive effect on raising management and carcass quality. Thus it is a need to install appropriate pens fitted to welfare-oriented management practices from growing to fattening period in Hanwoo cattle.

Relationship between Single Nucleotide Polymorphisms in the Peroxisome Proliferator-Activated Receptor Gamma Gene and Fatty Acid Composition in Korean Native Cattle

The peroxisome proliferator-activated receptor gamma (PPARγ) gene plays an important role in the biosynthesis process controlled by a number of fatty acid transcription factors. This study investigates the relationships between 130 single-nucleotide polymorphisms (SNPs) in the PPARγ gene and the fatty acid composition of muscle fat in the commercial population of Korean native cattle. We identified 38 SNPs and verified relationships between 3 SNPs (g.1159-71208 A>G, g.42555-29812 G>A, and g.72362 G>T) and the fatty acid composition of commercial Korean native cattle (n = 513). Cattle with the AA genotype of g.1159-71208 A>G and the GG genotype of g.42555-29812 G>A and g.72362 G>T had higher levels of monounsaturated fatty acids and carcass traits (p<0.05). The results revealed that the 3 identified SNPs in the PPARγ gene affected fatty acid composition and carcass traits, suggesting that these 3 SNPs may improve the flavor and quality of beef in commercial Korean native cattle.