Identification of Growth Hormone Releasing Hormone Gene in Local Buffalo (Bubalus bubalis) Using PCR-RFLP

Abstract

GHRH is a hypothalamic hormone which stimulates growth hormone secretion in the pituitary gland. The objective of this study was to identify polymorphisms Growth Hormone Releasing Hormone (GHRH) gene of Indonesian buffalo’s. A total of 320 blood samples from Indonesian buffaloes were used to determine polymorphism using PCR-RFLP method. The polymorphism of GHRH gene that spanned within exon 2 and exon 3 was amplified, and their mutation was detected using endonuclease HaeIII. In this study, there were three GHRH/HaeIII genotype (AA genotype 0%, AB genotype 36% and BB genotype 64%) determined by two alleles, A (18%) and B (82%). The frequency of A allele was found 15% for Semarang population, 19% for Mataram population, 2% for Medan population and 40% for Banten population. The frequency of B allele was found 85% for Semarang population, 81% for Mataram population, 98% for Medan population and 60% for Banten population. The observed heterozygosis values were different among populations. The highest heterozygosis (ĥ) 0,485 for Banten population and the lowest was 0.037 for Medan population and the average heterozygosis for all populations (Ĥ) detected was 0.270. Index fixation value of GHRH gene showed there was not fixed into one gene type (Fski ≠ 0). The smallest genetic distance value of GHRH gene was found between Semarang and Mataram population (0.001) and the highest between Medan and Banten population (0.202).