摘要:This study was aimed to identify polymorphism of growth hormone releasing hormone (GHRH) gene in 89 heads of Holstein-Friesian (HF) dairy cattle from Lembang Artificial Insemination Center/LAIC (17 bulls), Singosari Artificial Insemination Center/SAIC (32 bulls), and Cipelang Livestock Embryo Center/CLEC (40 cows); as well as in 4 breeds of female beef cattle from CLEC for comparison, providing Simmental (13 cows), Limousin (14 cows), Brahman (5 cows), and Angus (5 cows). This study used PCR-RFLP method by using HaeIII restriction enzyme. The enzyme cut the GHRH gene at nucleotides of GG|CC at the base positions of 118, 312, and 406 and produced 4 fragments of 118, 194, 94, and 45 bp respectively. Genotyping the GHRH gene produced two types of allele, namely A (312, 94, and 45 bp) and B (194, 118, 94, and 45 bp). These two alleles resulted in three types of genotype, namely AA (312, 94, and 45 bp), AB (312, 194, 118, 94, and 45 bp), and BB (194, 118, 94, and 45 bp). Frequency of the B allele was dominant to the A allele. Chi-Square analysis showed that all of HF dairy and beef cattle observed were in Hardy-Weinberg equilibrium (X2 < X2(0.05)). The highest heterozygosity value was 0.471 for HF bulls in LAIC, while the lowest one was for HF bulls in SAIC. Heterozygosity values in Simmental and Limousin cattles were higher than that of in HF cattle. The GHRH gene in HF and beef cattle was polymorphic, the exception was for Brahman with the only B allele. This result will improve the understanding of the polymorphism of GHRH gene in dairy and beef cattle.
其他摘要:Penelitian ini bertujuan untuk mengidentifikasi keragaman gen GHRH pada 89 ekor sapi Friesian Holstein di BIB Lembang (17 pejantan), BBIB Singosari (32 pejantan), dan BET Cipelang (40 betina); serta empat bangsa sapi pedaging betina dari BET Cipelang sebagai pembanding, meliputi Simental (13 ekor), Limousin (14 ekor), Brahman (5 ekor), dan Angus (5 ekor). Penelitian ini menggunakan metode PCR-RFLP dengan enzim restriksi HaeIII. Enzim HaeIII memotong sekuen gen GHRH pada nukleotida GG|CC di posisi basa 118, 312, dan 406 pb, sehingga menghasilkan 4 fragmen dengan panjang 118, 194, 94, dan 45 pb. Genotyping gen GHRH menghasilkan 2 tipe alel, yaitu alel A (312, 94, dan 45 pb) dan alel B (194, 118, 94, dan 45 pb). Kedua alel tersebut menghasilkan 3 genotipe, yaitu genotipe AA (312, 94, dan 45 pb), AB (312, 194, 118, 94, dan 45 pb), dan BB (194, 118, 94, dan 45 pb). Frekuensi alel B lebih tinggi daripada alel A. Frekuensi alel A dan B di BIB Lembang adalah 0,235 dan 0,765, BBIB Singosari 0,234 dan 0,766, dan BET Cipelang 0,225 dan 0,775. Analisis Chi-Kuadrat menunjukkan bahwa sapi perah FH dan sapi pedaging pengamatan dalam keseimbangan Hardy-Weinberg (X2 < X2 (0,05)), kecuali pada sapi FH di BIB Lembang, sapi Brahman, dan Angus di BET Cipelang. Nilai heterozigositas tertinggi adalah 0,471 untuk sapi FH pejantan di BIB Lembang, sebaliknya, nilai terendah adalah 0,344 untuk sapi FH pejantan di BBIB Singosari. Nilai heterozigositas sapi FH lebih rendah daripada sapi Simmental dan Limousin. Gen GHRH pada sapi FH dan sapi pedaging menunjukkan polimorfik, kecuali pada sapi Brahman yang hanya memiliki alel B.