Variations in the Bubaline Growth Hormone Gene in the Coding and Non-Coding Regions

Growth hormone is the major gene playing regulatory role in growth and metabolism of vertebrates. Several reports have identified mutations in Gh gene that are associated with animal productivity. The bovine Gh has been studied quite thoroughly but very little information regarding Buffalo growth hormone is available in literature. Buffalo is an important source of milk in Asia and there is a need to identify variations in the genes of buffalo Gh and its possible effects in milk production. The present research was carried out to explore DNA polymorphism in buffalo growth hormone gene. In this study we amplified a 5' flanking region covering exon 1 from local specie of Bubalus bubalis. As the 5' region of the Gh is very important in controlling the expression of the gene and minor changes in this sequence can affect its expression in blood. The PCR amplicon was sequenced and analyzed for homology with the help of BLAST search. Surprisingly, along with various point mutations in this region, we found that a considerable base sequence upstream exon 1 was similar to Bos mutus (yakQh1 chromosome 19) and did not align with reported Bubalus bubalis Gh sequence. Only 49% of the sequenced product aligns with Bubalus Bubalis though 90% of the sequence aligns with Bos mutus and Bos indicus Gh gene. A 46 bp inverted repeat sequence was also identified upstream exon 1. This report not only raises questions about the purity of the gene but also indicates mutations which may affect animal productivity like milk yield, growth regulation and carcass composition. There is a need to report these mutations so that their effects can be studied further. The complete animal history, means of semen supply or the methods used for its introduction can give clues about these findings. Keywords: Bubalus bubalis, Bos mutus, Bos indicus, Growth hormone, Mutation