Identifikasi keragaman Gen Growth Hormone Receptor (GHR AluI) pada Sapi Friesian Holstein di BIB Lembang, BBIB Singosari, dan BET Cipelang.
Abstract
Growth hormone receptor (GHR) is one factor affecting animal growth. GHR is required by growth hormone (GH) to carry out its effect on target tissues. The objective of this study was to identify polymorphism of the Growth Hormone Receptor gene in Holstein Friesian (HF) dairy cattle and beef cattle. Genotyping was performed on 126 animals. These consisted of HF 89 heads from BIB Lembang (17), BBIB Singosari (32), and BET Cipelang (40); as well as for 37 heads of four breeds of beef cattle including for Simmental (13), Limousin (14), Brahman (5), and Angus (5) for a comparison. Varian genetic of the GHR gene was identified by PCR-RFLP method using AluI restriction enzyme cutting the base position at AG|CT. Single nucleotide polymorphism (SNP) had been found in exon 10, coding for the cytoplasmic domain of GHR, which was located at position 81 bp (A/G) induced amino acid substitutions Ser/Gly. The product of amplification of GHR was 298 bp. Genotyping the GHR gene produced two alleles (A and G) resulting three genotypes (AA, AG and GG). The genotype AA was dominant in HF cattle from all locations, and also in Brahman and Limousin cattle from BET Cipelang. All of HF dairy cattle were in Hardy-Weinberg disequilibrium (χhit 2>χ0,05 2), in contrast, Simmental and Limousin were in Hardy-Weinberg equilibrium. The Hardy-Weinberg in Brahman and Angus values could not be calculated. Heterozigosity values in HF and beef cattle were low (ho<he). In beef cattle, Angus had highest heterozigosity value (0,600), while Brahman had the lowest heterozigosity value (0.000). The conclusion was that the variability of GHR|AluI gene can be used as a basic information for selection in growth caracteristic in the HF and beef cattle. Keywords: Beef cattle, Genetic polymorphism, GHR|AluI gene,