Cloning of Theileria annulata surface protein gene and sequence homology study in Indian isolates

Polymorphism in the sequences of key candidate molecules may affect the universal applicability of subunit vaccine against Theileria annulata from different geographical isolates. cDNA coding for TaSP, a polymorphic but highly antigenic surface protein of T. annulata was amplified from total macroschizont RNA and cloned in E. coli. The clone was sequenced and the deduced amino acid sequence was aligned and compared with that of Hisar isolate. Homology of 96.2% was observed between the two isolates, Both the N and C-terminal region of the sequence were highly conserved while few amino acid subsitutions were observed in the remaining central region of the sequence. The present study discusses the applicability of the protein in immunization trial against Indian isolates of T. annulata.