Identification of Growth Hormone Gene Polymorphism among Madura Cattle and Madura Crossed Cattle

Madura cattle was one of Indonesian local cattle and more than ten years was crossed with Limousin cattle (Madura crossed) to improve its productivities. The aim of this study was to identify polymorphism at growth hormone gene in Madura cattle and Madura crossed cattle by polymerase chain reaction-restriction fragment length polymorphism (PCR- RFLP). A 211 bp fragment of growth hormone gene spanning over fourth intron (49 bp) to fifth exon (162 bp) was amplified and digested with AluI restriction enzyme. The result indicated that Madura cattle was monomorphic for this locus producing only one genotype LL and one allele L. Polymorphism was found in Madura crossed cattle producing two alleles L and V. Two genotypes LL and LV were identified with higher allelic frequency for L allele. The frequencies of L and V alleles were 0.96 and 0.04, respectively. This polymorphism may be caused the lost of restriction AluI site, since this enzyme does not recognize its target sequence when a G is present instead of a C at position 53 of this fragment. Keywords: Polymorphism, growth hormone gene, Madura cattle, Madura crossed cattle