RESUMO
The genetic polymorphism of Mx1 gene was explored in Indian chicken breeds. PCR-RFLP analysis in 102 bp fragment of partial intron 13 and partial exon 14 of Mx1 gene revealed two genotypes viz. RS and SS with two alleles viz. R and S both in Naked Neck and Tellicherry breeds of chicken. The homozygous genotype RR was not identified. When deduced amino acid sequences were compared, the asparagine amino acid was found to be substituted in "R" allele for serine in "S" allele. PCR-SSCP analysis of 284 bp fragment in 5'-UTR and partial promoter region revealed three genotypes viz. CC, CG, and CH with three different alleles viz. C, G, and H in Naked Neck breed of chicken and five genotypes viz. DI, JK, KK, KL, and KM with six different alleles viz. D, I, J, K, L, and M in Tellicherry breed of chicken. The homozygous genotypes viz. GG and HH in Naked Neck and DD, II, JJ, LL, and MM in Tellicherry chicken was not identified. The nucleotide substitution rate estimated to be in the range of 0.004-0.011. The identified genetic variation can be helpful for better insight to disease resistance property of the Mx1 gene.