Polymorphism of growth hormone (GH/HaeIII) gene and its association with the performance of merino cross rams

Abstract

Merino cross sheep (75% Merino × 25% Garut) are introduced by the government of Indonesia for meat production purposes. The present study aimed to determine the polymorphism in the exon 2 region of the growth hormone (GH) gene (422 bp) in Merino cross rams using the PCR-RFLP technique and to analyze its relationship with body weight and body measurements of the rams. A total of 145 rams aged one-year-old with an average body weight of 29.08 ± 7.96 kg from the breeding station in West Java, Indonesia were considered as the experimental animals. It was indicated that a missense mutation of c.55G > A (p.G19S) was detected in the target sequence of the GH gene in Merino cross rams. The PCR-RFLP analysis in the GH gene of Merino cross with HaeIII restriction enzyme (GH/HaeIII) was observed in a moderate category with a polymorphic informative content (PIC) value of 0.22. Therefore, the G allele was more frequent than the A allele (0.85 versus 0.15). Furthermore, the genotype AA was not present among the sheep that were part of the study. However, the polymorphism of p.G19S was found to have no significant association with birth weight and body measurements in one-year-old Merino cross sheep. However, the GH/HaeIII gene in Merino cross rams exhibited polymorphism, primarily with two genotypes: GG (wildtype) and GA (carrier). The G allele was identified as the dominant allele in the ovine GH gene, occurring with a frequency of 0.85. Importantly, the polymorphism of the GH/HaeIII gene was significantly linked to birth weight and chest depth in one-year-old Merino cross rams. These findings provide preliminary insights that could potentially aid in the early stages of molecular selection for Indonesian Merino cross sheep.