Cloning and expression of a novel gene from Eimeria tenella.

A novel gene of E.tenella was cloned from the ESTs.The length of gene is 1 439 bp,which contains a 525 bp ORF encoding a putative 174 amino acids protein of 18.7 ku.Real-time PCR revealed that the gene was expressed at higher level in sporozoites of E.tenella than other developmental stages(unsporulated oocysts,sporulated oocysts and merozoites).The gene was subcloned to prokaryotic expresson vector pGEX-4T and transformed into E.coli BL21(DE3) for expression.SDS-PAGE indicated that the recombinant protein was 44.7 ku and expressed to the highest level at 6 hour after induction by IPTG,and most of the recombinant protein was soluble.Western blot revealed that the recombinant protein could be specifically recognized by polyclonal antibodies against E.tenella.