Cytochrome P450, family 2, subfamily A, polypeptide 6 (CYP2A6) and kinesin-like protein KIF12 (KIF12) genes are predicted as candidate genes which play important roles in lamb flavour and odour. The aim of this study was to analyse the genotype polymorphism of CYP2A6 and KIF12 genes, to study association and expression of these genes with lamb flavour and odour. Identification of genes polymorphism and associations of CYP2A6 and KIF12 genes were performed using PCR-RFLP method and GLM analysis. The PCR-RFLP products of CYP2A6 and KIF12 were digested by restriction enzyme BsmAI and BfaI, respectively. The expression of CYP2A6 gene was performed using qRT-PCR. The results showed that the CYP2A6 and KIF12 genes were polymorphics. The CYP2A6 gene found to have two genotypes (TT and GT), whereas the KIF12 gene found to have three genotypes (CC, CT, and TT). The CYP2A6 and KIF12 genes were in Hardy Weinberg Equilibrium (HWE). Association analysis showed that CYP2A6 (g.49170107 G>T) was significantly (P<0.05) associated with 3-methylindole (MI) or skatole, while KIF12 (g.9617965 C>T) was not significantly associated with lamb flavour and odour. The GT genotype exhibited a greater 3-methylindole (MI) or skatole than the TT genotype (P<0.05). The mRNA expression analysis showed that CYP2A6 mRNA expression was higher (P<0.01) in animals with the TT genotype. These results will improve the understanding of the functions of the CYP2A6 in lamb flavour and odour, especially in term of 3-methylindole (MI) or skatole compound within the liver and will shed light on CYP2A6 as a candidate in the selection of sheep with low lamb flavour and odour.

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This study was aimed to identify single nucleotide polymorphism (SNP) and pathway analysis of APOA5 with fatty acids traits in sheep. A total of 47 rams consisted of 20 heads of Javanese Fat Tailed (JFT), 17 heads of Javanese Thin Tailed (JTT), and 10 heads of Garut Composite Sheep (GCS) were used in this study. Fatty acids traits were measured at the age of 12 months with the average body weight of 25-30 kg. Identification of polymorphism of APOA5 (g.26929941 C>T) gene were analyzed using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP). The pathway analysis of APOA5 gene was performed using Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. The SNP of APOA5 gene were found polymorphic with three genotypes (CC, CT, and TT). The gene frequency of CC, CT, and TT were 0.83, 0.11, and 0.06, respectively. The chi square test revealed that the locus of APOA5 (g.26929941 C>T) was in Hardy-Weinberg equilibrium, except in thin tailed sheep. The chi-square values of JFT, JTT, and GCS were 0.05, 0.03, and 0.04, respectively. A SNP of APOA5 was associated (P<0.05) with polyunsaturated fatty acids including eicosapentanoic acid (C20:5n3) and docosahexanoic (C22:6n3) and saturated fatty acid lauric acid (C12:0) in combined population (JFT, JTT, and GCS). Furthermore, pathway analysis showed that APOA5 belonged to phagosome and peroxisome proliferator-activated receptors (PPAR) signaling pathway. In conclusion, this analysis has identified APOA5 and related pathway crucial for fatty acid composition and metabolism in sheep, as well as this gene provide molecular marker to select sheepmeat with high unsaturated fatty acid.

ABSTRAK Karakteristik karkas dan sifat perlemakan pada daging domba dikontrol oleh banyak gen salah satunya gen DGAT1 (Diacylglycerol Acyltransferasel 1). Penelitian ini bertujuan mengidentifikasi SNP (Single Nucleotide Polymorphism) gen DGAT1 pada titik mutasi g.8539 C>T dan asosiasinya terhadap karakteristik karkas dan sifat perlemakan pada domba Indonesia. Total sampel domba yang digunakan sebanyak 150 buah terdiri dari 35 sampel domba compass agrinak (DCA), 36 sampel domba barbados cross (DBC), 41 sampel domba komposit garut (DKG), 20 sampel domba ekor gemuk (DEG), dan 18 sampel domba ekor tipis (DET). Karakteristik karkas dan sifat perlemakan diukur dari domba jantan berumur 10-12 bulan. Identifikasi keragaman DGAT1|ALuI dianalisis dengan metode PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism). Hasil keragaman gen DGAT1 bersifat polimorfik dalam DET dan DEG, sedangkan DCA, DBC, dan DKG bersifat monomorfik. Dua genotipe disebut CC dan  CT ditemukan dalam DET dan DEG. Titik mutasi gen DGAT1 berasosiasi (P<0.05) dengan karakteristik karkas, yaitu bobot dan panjang karkas. Selain itu, keragaman gen DGAT1 juga berasosiasi signifikan (P<0.05) dengan asam lemak jenuh, yaitu asam stearat (C18:0) dan asam arakidat (C20:0) dan asam lemak tak jenuh tunggal, yaitu asam oleat (C18:1n9c). Gen DGAT1 memiliki kontribusi dalam karakteristik karkas dan komposisi asam lemak pada domba.Kata Kunci: domba, gen DGAT1, karakteristik karkas, PCR-RFLP, sifat perlemakan                                                              ABSTRACT            Characteristic of carcass and fatness traits of sheep is regulated by many genes such as DGAT1 (Diacylglycerol Acyltransferasel 1) gene. The research was aimed to investigate SNP (Single Nucleotide Polymorphism) of DGAT1 and its association with characteristic of carcass and fatness traits in Indonesian sheep. A total sample of sheeps used 150 rams of 10–12 months consisted 35 samples of compas agrinak sheep (CAS), 36 of barbados cross (BCS), 41 of garut composite (GCS), 20  of javanese fat tailed (JFT), and 18 of javanese thin tailed (JTT). Identification variant of DGAT1|ALuI were performed by PCR-RFLP (Polymerase Chain Reaction-Restriction Fragment Length Polymorphism). The results of polymorphism of DGAT1 were found in JTT and JFT. However, SNP of DGAT1 in CAS, BCS and GCS were monomorfic. Two genotype namely CC and CT were found in JTT and JFT populations. A SNP of the DGAT1 was associated (P<0.05) with characteristic of carcass, including weight and length of carcass. The variant of DGAT1 was associated too with saturated fatty acids (SFA) including stearic acid (C18:0) and arachidic acid (C20:0), and mono unsaturated fatty acid (MUFA) including oleic acid (C18:1n9c). The DGAT1 gene was contribute to characteristic carcass and fatty acid composition in sheep.Keywords: DGAT1 gene, characteristic carcass, fatness traits, PCR-RFLP, sheep

The aim of this study was to investigate the association and expression of LEPR with fat quality, flavour and odour in sheep. A total of 47 rams were used in this study. Fatty acids composition, BCFA (Branch Chanin Fatty Acids; MNA, MP, MOA, and EOA) and skatole (MI) representing fat quality, flavour and odour in sheep were measured at ages of 10-12 months old. Identification of novel variant and expression analysis of LEPR gene with different fat quality, odour and flavour were performed by PCR RFLP and qRT-PCR, respectively. A SNP in genomic region g.40854778 A>C of the LEPR gene was associated (P<0.05) with fat quality of saturated fatty acids (SFA) including [tricosanoic acid (C23:0) and tetracosanoic acid (C24:0)] and poly unsaturated fatty acid (PUFA) [docosahexaenoic acid (C22:6n3)]. However, the novel variant of LEPR was not significantly associated (P<0.05) with fat content, odour and flavour (MNA, MP, MOA, EOA, and MI). The mRNA expression analysis showed that LEPR mRNA expression was higher (P<0.01) in sheep found at the AA genotype. It could be concluded that variant SNP in the LEPR may contribute to fatty acid composition without influencing odour and flavour traits in sheep.

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ABSTRAKKinesin Family 12 (KIF12) merupakan gen yang terlibat dalam mediasi kaskade antioksidan dalam sel beta sebagai sebuah target intraselular dari kelebihan asupan lemak atau lipotoksit. Penelitian ini bertujuan untuk mengidentifikasi karakterisasai gen KIF12 melalui identifikasi keragaman dan asosiasi gen KIF12 terhadap komposisi asam lemak pada domba. Sampel domba yang digunakan sebanyak 35 ekor yang terdiri dari Domba ekor Gemuk (DEG) dan Domba Ekor Tipis (DET) masing-masing 20 dan 15 ekor. Titik mutasi gen KIF12 berada pada posisi g.9617965 C>T.  Identifikasi keragaman gen KIF12 dianalisis menggunakan Polymerase Chain Reaction - Restriction Fragment Length Polymorphism (PCR-RFLP) dengan menggunakan enzim BfaI. Hasil keragaman gen KIF12 bersifat polimorfik dengan ditemukan tiga genotipe yaitu CC, CT, dan TT. Hasil Uji chi square menunjukkan bahwa lokus KIF12 berada pada keseimbangan Hardy-Weinberg (HWE) pada pada DET, hal berbeda ditunjukakan pada DEG. Titik mutasi gen KIF12 berasosiasi secara signifikan  (P <0.05) terhadap asam lemak jenuh (SFA)  asam laurik (C12:0), asam miristik (C14: 0) and asam heptadenoik (C17: 0) juga asam lemak jenuh tunggal (MUFA), asam miristoleinik (C14: 1) and asam oleik (C18: 1n9c). Gen KIF12 memiliki potensi untuk digunakan sebagai penanda seleksi terhadap komposisi asam lemak.Kata kunci:  domba, asam lemak, KIF12, PCR RFLPABSTRACTKinesin Family 12 (KIF12) is one of gene which involved in mediates an antioxidant cascade in beta cells as an intracellular target of excess fat intake or lipotoxicitys. This study was aimed to identify the polymorphism and association of KIF12 gene as candidate gene for fatty acid composition in Indonesian sheep including fat-tailed sheep and thin-tailed sheep. The sample of sheeps used 35 heads consist fat-tailed sheep and thin-tailed sheep as many as each 20 and 15 samples. Identification of polymorphism of KIF12|BfaI gene were analyzed using Polymerase Chain Reaction - Restriction Fragment Length Polymorphism (PCR-RFLP). The results of polymorphism of KIF12 gene were polymorphic for three kind of genotypes of CC, CT, and TT. The chi square revealed that the locus of KIF12 was deviated in Hardy-Weinberg equilibrium (HWE) in fat-tailed sheep, but was in HWE in thin-tailed sheep. A SNP of KIF12 was associated (P <0.05) with saturated fatty acids (SFA) including lauric acid (C12:0), myristic acid (C14: 0) and heptadecanoic acid (C17: 0) as well as monounsaturated fatty acids (MUFA), namely miristoleinic acid (C14: 1) and oleic acid (C18: 1n9c).The KIF12 gene was the potential to be used as a marker of selection for fatty acid compositions.   Keywords : sheep, fatty acids, KIF12, PCR-RFLP

THO Complex 5 (THOC5) gene involves in lipid and fatty acid metabolism. The aim of this study was to analyse polymorphism of THOC5 gene and its association with fatty acid composition in sheep. A total of 120 rams at the age 12 month with the average body weight of 25–30 kg was used for identification of gene polymorphism using Polymerase Chain Reaction- Restriction Fragment Length Polymorphism (PCR-RFLP). 83 rams, representative from different genotypes of sheep were used for association study using a General Linear Model (GLM). The results identifed polymorphism in the THOC5 gene. The THOC5 gene showed two genotypes: CC and CT genotype. Association analysis revealed that THOC5 (g.68234589 C>T) was significantly (P<0.05) associated with fatty acid composition including unsaturated fatty acid: palmitoleic acid (C16:1), and saturated fatty acid: stearic acid (C18:0). The CC genotype was associated with higher level of unsaturated fatty acid and lower level of saturated fatty acid, while the CT genotype was vice versa. This result indicates that THOC5 gene (g.68234589 C>T) may contribute to fatty acid composition in sheep, as well as this polymorphism could be used as a candidate to select sheepmeat with high unsaturated fatty acid and low saturated fatty acid.