HaeIII-RFLP Polymorphism of growth hormone gene in Savanna and Kalahari goats

摘要

Growth hormone (GH) plays an important role in several biological processes such as reproduction, lactation, metabolism and growth of livestock animals. The objectives of this study were to screen growth hormone (GH) gene variants and to identify the polymorphism of GH gene in Savanna and Kalahari goats using PCR-RFLP technique. Genomic DNA was obtained from goat blood samples and amplified by PCR-RFLP using five growth hormone genes. The present study showed two variations were present in growth hormone (GH1 and GH5) of goats. The analysis of 422 bp GH1 fragment revealed polymorphisms with three genotypes (AA, AB and BB). The AB genotype was identified as with the highest frequency in Savanna and Kalahari goats with values of 0.88 and 0.64, respectively. GH5 revealed three genotypes (GH, GG and HH) which differed in patterns from GH1. The highest genotype frequencies of GH5 in Savanna goats were 0.57 and 0.37 for GG and GH genotypes, respectively. Observed genotypes and frequencies in Kalahari goats differed from Savanna goats. The highest frequencies of GH and HH genotypes were found in Kalahari goats with value 0.5 and 0.36, respectively. Further sequence analysis showed that two single nucleotide polymorphisms (SNPs) were found in GH2 in exon 4 that caused a change in amino acid coding. One SNP located in exon 3 in GH6 was identified but did not change the amino acid coding.