study on interferon gamma gene polymorphism in shaul sheep

interferon gamma (ifn-g) is a cytokine produced by activated t lymphocytes and natural killer cells. it plays an important role in innate and adaptive immunity. ifn-g gene is polymorphic and its haplotype has been associated with resistance to nematode infestations which are the most important parasites of domestic sheep worldwide. to evaluate ifn-g polymorphism in iranian shaul sheep population, 136 blood samples were collected. genomic dna were extracted and amplified by pcr using specific primers for exon 3 of ifn-g gene. after gene amplification, sscp and heteroduplex mobility analysis carried out on polyacrylamid gel. five unique sscp patterns were detected in this population which 3 of them represent 3 alleles. although heteroduplex mobility analysis demonstrated that all samples were homozygous, sscp could reveal heterozygosity at frequency of 40. 4% in the studied population. data obtained from the present study have revealed that ifn-g gene was a highly polymorphic in iranian shaul ecotype. this will be useful to study host-pathogen interaction and to evaluate association between resistance or susceptibility to disease with ifn-g in this ecotype.