Detection of growth hormone (GH|MspI,GHR|AluI, Pit1|HinfI) genes polymorphism and its association with body weight of Grati-Bali Cattle (Bos sondaicus)

Abstract

Bali cattle is the only native Indonesian cattle that still exist and well developed. Bali cattle are known to have adaptability and a higher percentage of carcasses than other local cattle. Molecular selection related to growth traits can be done by exploration of growth hormone genes in the population of Bali cattle. This study aims to detect the level of polymorphism of GH, GHR and Pit1 genes and their association with the body weight of Grati-Bali cattle as a first step to produce a MAS (marker assisted selection). A total of 171 DNA samples Grati-Bali cattle were collected from the Beef Cattle Research Station experiment cages and its body weight data of 2014-2018 include birth weight (BW), weaning weight (WW) and yearling weight (YW). Blood samples were isolated using a zymo extraction kit. Detection of the diversity of growth hormone genes (GH, GHR and Pit1) using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method with MspI, AluI, HinfI restriction enzymes. Data analysis used Chi-Square test for genotype, allele frequencies and Hardy-Weinberg Equilibrium (HWE). Association analysis used the GLM model. The results showed that the average BW, WW and YW of Grati- Bali cattle in the study were 13.3±0.3 kg, 73.7±2.4 kg and 121.3±4.2 kg, respectively and there was no statistical difference in body weight for male and female calves. The analysis showed that GH and Pit1 genes were detected by 1 genotypes respectively, each with an allele frequency > 99% and monomorphic. GHR gene was detected 3 genotypes namely AA, AG, GG, with allele frequencies A were 0.579 and G were 0.421. The GHR gene PIC value was in the moderate category. It was concluded that the GHR|AluI gene in Bali cattle is polymorphic but has not been significantly associated with the body weight of Grati-Bali cattle.