Identifikasi Keragaman Gen Growth Hormone Releasing Hormone (GHRH|HaeIII) Pada Sapi Friesian Holstein Di BIB Lembang, BBIB Singosari, Dan BETCipelang

Abstract

This study was aimed to identify polymorphism of the GHRH gene in Holstein Friesian (FH) cattle from BIB Lembang, BBIB Singosari, and BET Cipelang; and beef cattle from BET Cipelang for a comparison. Blood samples used were 126 samples, consisting of 49 HF bulls from BIB Lembang (17 hds), BBIB Singosari (32 hds), and HF cows from BET Cipelang (40 hds); and a number of 37 hds of beef cattle consisting of Simmental (13 hds), Limousin (14 hds), Brahman (5 hds), and Angus (5 hds) from BET Cipelang. This study used PCR-RFLP method using restriction enzyme HaeIII. This enzyme restricted the GHRH gene sequences at the bases GG | CC at the positions of 118, 312, and 406 bp resulting four fragments with the lengths of 118, 194, 94, and 45 bp respectively. Genotyping GHRH gene produced two alleles, namely A and B alleles. These alleles produced three genotypes, namely the genotypes of 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 higher than the A allele. Frequencies of the A and B alleles in HF were in BIB Lembang 0,235 and 0,765, BBIB Singosari 0,234 and 0,766, and BET Cipelang 0,225 and 0,775. Chi-square analysis showed that all of HF and beef cattles were in Hardy-Weinberg equilibrium (χ2 < χ2 (0.05)), the exception in HF cattles in BIB Lembang, Brahman and Angus cattles in BET Cipelang. The highest heterozigosity values in HF was found in BIB Lembang (0,471), while the lowest was in BBIB Singosari (0,344). Heterozygosity values in the HF were lower than those of Simmental and Limousin beef cattle. GHRH gene in HF and beef cattle were polimorfic, the exception in Brahman cattle as possesing only the B allele.