Polymorphism of Insulin-Like Growth Factor 1 Gene in Najdi Cattle Populations

The Insulin-like Growth Factor 1 (IGF-1) system plays a critical endocrine role controlling nutrient metabolism in dairy cattle and it is a group of structurally-related polypeptides that regulate the growth of many types of mammalian cells. In liver, IGF-1 is dynamically regulated by lactation and energy balance. Less is known about the regulation of IGF-1 and IGF-binding protein mRNA in reproductive tissues and plays an important role in bovine follicular growth, acquisition of oocyte competence and embryo viability. The present study describes polymorphism of IGF-1 gene in Najdi cattle populations. In order to characterization polymorphism, blood sample were collected from 84 Najdi cattles from Shadegan, Mahshar cities and Shushtar station. DNA extraction was based on Boom method and exons 1 of the IGF-1 gene were amplified to produce a 249 bp fragment. The amplified fragment were digested with Eco105I (SnaBI) restriction endonuclease and then subjected to electrophoretic separation in ethidium bromide-stained 2% agarose gel. The results were revealed two alleles, A and B. Three genotypes were observed, Frequencies were 2.38, 14.28 and 83.33% for AA, AB and BB, respectively. This gives frequencies of 0/0952 and 0/9048 for A and B alleles. The populations were in hardy-weinberg equilibrium. It is possible that this gene has not exposed to selection. The heterozygosity is low and inbreeding is estimated high.