Single nucleotide polymorphism in Egyptian cattle insulin-like growth factor binding protein-3 gene

Insulin-like growth factor binding protein-3 (IGFBP-3) gene is a structural gene responsible for the multiple influences of insulin-like growth factors (IGFs) system. It is considered as a candidate gene for growth and production traits. In the present study, we aimed to determine the genetic polymorphism of Egyptian cattle IGFBP-3 gene. The amplified fragment of cattle IGFBP-3 gene at 651-bp was digested with three different endonucleases; HaeIII, MspI and TaqI. The digestion of the PCR products with MspI and TaqI endonucleases revealed similar restriction patterns in all tested animals. Digestion of the PCR product with HaeIII restriction enzyme revealed three different genotypes in Egyptian cattle due to the presence of two alleles; allele A with 7 digested fragments resulting from the presence of 6 restriction sites and allele C with 8 digested fragments resulting from the presence of 7 restriction sites; six sites as allele A in the addition of another restriction site at position 298^299 as a result of SNP (A → C) in C allele at position 299. The restriction patterns of IGFBP-3/HaeIII showed that forty-six examined animals are genotyped as AA, CC and AC with frequencies of 21.74%, 21.74% and 56.52%, respectively. It is concluded that the IGFBP-3/HaeIII polymorphism may be utilized as a good marker for genetic differentiation between cattle animals for different body functions such as growth, metabolism, reproduction, immunity and energy balance. The nucleotide sequences of Egyptian cattle IGFBP-3 A and C alleles were submitted to GenBank with the accession numbers KF899893 and KF899894, respectively.