Investigation of IGF-1 gene polymorphism by PCR-RFLP in crossbreed cow population in khouzestan province

The insulin-like growth factor-1 (IGF-1) gene are major regulators of postnatal growth and metabolism and thus play critical roles in the control of lactation, mammary gland development, growth processes, and fertility in cattle. This gene is located on chromosome 5 in the cow. The IGF-I hormone is secreted by most of tissues, but it is mainly secreted from the liver and after releasing, it is transferred to other tissues. The IGF-I hormone plays a key role in various physiological and metabolic processes. Factors such as growth hormone, nutrition, insulin and temperature will influence on serum IGF-I concentration. In order to study the IGF-I gene polymorphism, blood samples were taken randomly from 93 hybrid cows in Khuzestan province. DNA extraction from blood samples and the polymerase chain reaction (PCR) for amplification of 249-bp fragment of Exon 1 of the gene were performed. The cutting SnaBI enzyme was used for enzymatic digestion. The results showed that the genotype frequencies of AA, AB and BB, respectively are as 0.06, 0.53 and 0.41. AB genotype and AA genotype had the highest and the lowest frequencies in the herd, respectively. The frequencies of allele A and allele B in the population were estimated respectively as 0.33 and 0.67. Due to the selection, the Hardy Weinberg balance did not exist in the cattle.