Genetic Diversity of Jawa-Brebes Cattle based on Reproductive Traits Markers of the Growth Hormone Gene

The mutations of the growth hormone (GH) gene significantly affect the fertility traits of various cows including service per period and calving interval. Identification of GH gene polymorphism is crucial to preserve the genetic resources of Jawa-Brebes cattle. Thus, we identified the single nucleotide and genetic polymorphisms in Jawa-Brebes cattle based on intron 3 to exon 5 of the GH gene. The amplified products (1,135 bp) of the GH gene from 24 heads of Indonesian cows (Jawa-Brebes, Bali, Madura, and Peranakan Ongole [PO]) were sequenced using the 1st BASE sequencing method. Clustal W and phylogenetic analyses to detect single nucleotide polymorphism and relationship to other breeds were used in the study. A total of 13 variable sites with 10 parsimony and 3 singleton sites were detected in the GH gene
within Jawa-Brebes cattle, namely 3 sites in intron 3, 6 sites in intron 4, and 4 sites in exon 5. Three Indels were detected in Jawa-Brebes cattle at the 1,540th (g.1539_1540insT), 1,549th (g.1548_1549insG), and 1,895th (g.1894_1895insC) positions. The genetic distance was 0.000 to 0.013 within Jawa-Brebes cattle. Jawa-Brebes cattle were genetically close to Indonesian local cattle (Bali, Madura, and PO cattle). In addition, Jawa-Brebes cattle had a closer relationship with Bos indicus than Bos taurus. The sequences of intron 3, intron 4, and exon 5 of GH gene were polymorphic. The study provided initial bioinformatics of GH gene sequence that might be used to preserve Jawa-Brebes cattle and as reproduction traits marker-assisted selections in further investigation.