Identification of single nucleotide polymorphisms in IgL and IFNɣ loci in some indigenous chickens

Genetic resistance to diseases is very important in chickens. Determining the genetic diversity of the chicken immune system is one of the main options for examining differences in resistance to diseases. Two hundred blood samples were taken from indigenous chickens populations of Common, West Azarbaijan, Marandi and Mazandarani and genomic DNA was extracted by salting out method. The allelic polymorphisms were investigated in IgL and IFNɣ loci involved in the immune system using PCR-RFLP and the Sau96I and Tsp509I enzymes. After enzymatic digestion, for IgL marker site (354 bp), three genotypes of AA, AB and BB and allele A (with two bands of 173, 161 and two bands of 10 bp) and allele B (with three bands of 161, 103 and 70 and two bands of 10 bp) and for IFNγ marker site (129 bp), three genotypes of CC, CG, and GG and allele C (with one band of 129 bp) and allele G (with two bands of 90 and 39 bp) were identified. The total populations for loci were not in Hardy-Weinberg equilibrium. The Shannon information index for markers’ sites of IgL and IFNɣ (0.67 and 0.69, respectively), fixation index values (-0.24 and -0.18, respectively) and the highest observed heterozygosity index (0.61 and 0.59, respectively) was estimated. Regarding the presence of polymorphism in the studied loci, it is possible to use these candidate genes in selection programs to increase disease resistance.