Cloning and sequence analysis of exon 5 to exon 6 region of Tapasin Gene in exotic and indigenous chicken breeds

Tapasin is an endoplasmic reticulum (ER) anchored glycoprotein of 48KDa. Major function of the Tapasin is to assist the expression of major histocompatibility complex I (MHC class I) molecules on the cell surface. The present study was undertaken to investigate and compare the genetic makeup of exon 5-exon 6 region of avian Tapasin gene in White Leghorn, White Plymouth Rock, Rhode Island Red (exotic breeds), Kadaknath and Naked neck (indigenous breeds) of chicken. Tapasin gene fragment from exon 5-exon 6 was amplified and sequences of different lengths were obtained. Nucleotide sequence analysis revealed sequence variations between the different chicken breeds studied and nucleotide sequence deletions in Nacked neck breed. Variations in nucleotide sequences within the coding region may sometimes lead to a change in amino acid sequences which may result a change in protein structure. All these replacements in amino acid sequences of different breeds might affect the antigenic peptide loading on empty MHC Class I molecules within the endoplasmic reticulum there by having effects in the cell mediated immunity (CMI) status of these birds.