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Heugu (Korea Black Cattle) is one of the indigenous cattle breeds in Korea; however there has been severe lack of genomic studies on the breed. In this study, we report the first whole genome resequencing of Heugu at higher sequence coverage using Illumina HiSeq 2000 platform. More than 153.6 Giga base pairs sequence was obtained, of which 97% of the reads were mapped to the bovine reference sequence assembly (UMD 3.1). The number of non-redundantly mapped sequence reads corresponds to approximately 28.9-fold coverage across the genome. From these data, we identified a total of over six million single nucleotide polymorphisms (SNPs), of which 29.4% were found to be novel using the single nucleotide polymorphism database build 137. Extensive annotation was performed on all the detected SNPs, showing that most of SNPs were located in intergenic regions (70.7%), which is well corresponded with previous studies. Of the total SNPs, we identified substantial numbers of non-synonymous SNPs (13,979) in 5,999 genes, which could potentially affect meat quality traits in cattle. These results provide genome-wide SNPs that can serve as useful genetic tools and as candidates in searches for phenotype-altering DNA difference implicated with meat quality traits in cattle. The importance of this study can be further pronounced with the first whole genome sequencing of the valuable local genetic resource to be used in further genomic comparison studies with diverse cattle breeds.

The pork from black-coated pigs is famous among-consumers for better eating quality. The loci affecting black coat color was identified in pig chromosome 6 in which several genetic effects on pork quality have been reported. The melanocortin 1 receptor (MC1R) gene is a major gene which plays a key role in regulation of eumelanin (black/brown) and phaeomelanin (red/yellow). In this study, the MC1R gene polymorphism was analyzed for pig breed determination and genetic association with pork quality traits. MC1R Ala243Thr variation was analyzed to determine a specific genotype for four commercial pig breeds (Landrace, Yorkshire, Berkshire and, Duroc) and a Korean native pigs (KNP). Then we developed original KNP-specific DNA markers to determine the pork from black-coated pigs using MC1R DNA sequences. The total length of the MC1R coding sequence ranged 1451bp in KNP. KNP had the 0201 allele pertaining to E D1 but some of the KNP had the E P allele, probably reflecting the geneticintrogression of E P allele into KNP. Furthermore, a relationship between Leu102Pro single nucleotide polymorphism (SNP) genotype and pork quality phenotype were analyzed in F2 reciprocal-crossbred population between KNP and Yorkshire. Association analysis indicated that the allele of the MC1R gene has no effect on pork quality. These results suggest that black coat-color is not directly associated with preferred pork quality, but the black-coat color pig breed may have other genetic components for superior pork quality.

Fatty acid synthase (FASN) is a multi-functional enzyme with a central role in the synthesis of long-chain fatty acid and has been considered as a positional candidate gene for BTA 19 quantitative trait loci (QTL) affecting milk-fat content and fatty acid composition. In this study, we sequenced the FASN gene in several cattle breeds including Hanwoo and imported beef cattle, and identified novel DNA polymorphisms and their linkage relationship in Hanwoo. We found a significant frequency difference of the FASN (AF285607) g.17924 A→G polymorphism between Hanwoo (70%) and other breeds and this polymorphism has been known for an association with fatty acid composition in Angus.Furthermore, by direct DNA sequencing in 18 unrelated Hanwoo, we identified 27 SNPs including nine novel variations in the FASN gene. Among 27 SNPs identified in the FASN gene, four SNPs were further genotyped in 100 Hanwoo and 96 imported beef cattle, and analyzed for haplotype construction and association with beef quality traits. We performed haplotype block and linkage disequilibrium studies using four selected SNPs. Two different haplotype blocks (block A: g.10568 C→T and g.11280 G→ A; block B: g.13125 C→T and g.17924 G→A) were constructed and the block A in particular had a very high r2 (0.936), which indicated a nearly complete linkage disequilibrium existed between the g.10568 C→T and g.11280 G→A polymorphisms. A total of four major haplotypes (frequency > 0.05) were identified with the four polymorphisms including TATG (0.36), CGCG (0.31), CGTA (0.19) and TACG (0.06).Statistical association analysis revealed that the g.10568 C→T and g.11280 G→A polymorphisms in the FASN were significantly associated with meat color (P=0.004) and texture (P=0.0114). The g.13125 C→T and g.17924 G→A polymorphisms in the FASN were also significantly associated with back-fat thickness and quantity index (P=0.0179 and 0.0495, respectively). Our findings suggested that the FASN gene polymorphisms may be used for determining the (unsaturated) fatty acid contents and carcass trait in the Hanwoo beef.

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