ABSTRAK Gen FTO berfungsi sebagai regulasi homeostasis, deposisi lemak dan pengaturan obesitas. Penelitian ini bertujuan untuk mengidentifikasi polimorfisme SNP g.125550A>T di ekson 3 gen FTO pada bangsa sapi potong Indonesia. Sampel darah diperoleh dari 209 ekor sapi, terdiri atas sapi bali (44), madura (20), Pesisir (20), katingan (20), Peranakan ongole (PO) (22), Pasundan (20), Sumba Ongole (SO) (11), brahman (20), simental (15), dan limousin (18). Polimorfisme gen FTO dianalisis menggunakan metode PCR-RFLP (HpyCH4III) dan direct sequencing. Hasil genotiping SNP g.125550A>T adalah polimorfik (genotipe AA, AT, dan TT) pada sapi madura, pesisir, katingan, PO, pasundan, SO, brahman, simental, dan limousin. Frekuensi alel A dan T masing-masing adalah 0,70, 0,68, 0,84, 0,89, 0,70, 0,86, 0,90, 0,73, 0,69 dan 0,30, 0,33, 0,16, 0,11, 0,30, 0,14, 0,10, 0,27, 0,31. Nilai Ho dan He masing-masing adalah 0,60-0,14 dan 0,44-0,18 serta dalam keseimbangan Hardy-Weinberg (P>0.05). Sementara pada sapi bali bersifat monomorfik hanya bergenotipe AA. Hasil sekuensing SNP g.125550A>T ditemukan mutasi tranvesi A menjadi T pada posisi nukleotida g.125550. Berdasarkan hasil penelitian ini, dapat disimpulkan bahwa SNP 125550A>T gen FTO beragam dan berpotensi dijadikan marka genetik untuk kualitas daging pada bangsa sapi potong Indonesia.Kata Kunci: gen FTO, PCR-RFLP, Sapi, SNP g.125550A>TABSTRACTThe FTO gene functions as regulation of homeostasis, fat deposition and regulation of obesity. This study aimed to identify the polymorphism of SNP g.125550A>T in exon 3 of FTO gene in Indonesian beef cattle. Blood samples were collected from 209 cattle, including bali (44), madura (20), pesisir (20), katingan (20), PO (22), pasundan (20), SO (11), brahman (20), simental (15), and limousin (18). Polymorphism of the FTO gene was analyzed using PCR-RFLP (HpyCH4III) and direct sequencing methods. The results of genotyping SNP g.125550A>T was polymorphic (AA, AT and TT genotypes) in madura, pesisir, katingan, PO, pasundan, SO, brahman, simental, and limousin cattle. The frequency of A and T alleles were 0,70, 0,68, 0,84, 0,89, 0,70, 0,86, 0,90, 0,73, 0,69 and 0,30, 0,33, 0,16, 0,11, 0,30, 0,14, 0,10, 0,27, 0,31 respectively. The values of Ho and He were 0,60-0,14 and 0,44-0,18 respectively and in Hardy-Weinberg equilibrium (P>0,05). While in Bali cattle was monomorphic (AA genotype). Results of sequencing SNP g.125550A>T of the FTO gene found a transverse mutation A to T at the nucleotide position g.125550. As a result of this study, it can be concluded that SNP 125550A>T of the FTO gene was diverse and potentially used as genetic markers for meat quality in Indonesian beef cattle.Keywords: cattle, FTO gene, PCR-RFLP, SNP g.125550A>T.