Study On 8-kDa Diagnostic Antigen Family Genes From Taeniidae

Objectives: Clon and analysis the 8 ku protein family gene from Taenia saginata and Echinococcus granulosus.①Potential valuable antigenic genes are expected to be found gene variation of Taenia saginata 8 ku protein family genes through molecular analysis, which provides information for molecular evolution analysis on TSA8 ku proteins of Taeniidae.②The valuable diagnostic genes AgB1 and AgB2 form Cystic echinococcus are cloned and expressed in Escherichia coli, which establishes an unvarying foundation for serological detect of animals with CE infection. Methods:①8 ku family genes were cloned from Taenia saginata oncospheres and analyzed at genomic DNA and transcriptional level, respectively.②AgB1 and AgB2 gene were cloned from Cystic echinococcus by RT-PCR method and expressed on prokaryotic expression system. Results:①3 types of 23 different gene sequences exist in 224 positive recombinant clones, which includes 2 types of A genes with a 216 bp of open reading frame encoding 71 amino acids; 2 types of B genes with a 249 bp of open reading frame encoding 82 amino acids; 19 types of C genes with a 258 bp open reading frame encoding 85 amino acids. TSA8KD-14 gene has a significant amino acid residue divergence with other TSA8 ku genes indicating that it's a very special gene.②Comparison of relative Taeniidae 8 ku protein sequences indicates that high similarity of amino acids existes between TSA8KD-1 gene, TSA8KD-2 gene, TSA8KD-3 gene, TSA8KD-4 gene, TSA8KD-5 gene, TSA8KD-11 gene, TSA8KD-12 gene and TSA8KD-17 gene and important diagnositic antigen genes TsRS1, TsRS2 and Ts14 from Taenia solium.③AgB1 with a 198 bp of open reading frame and AgB2 gene with a 213 bp of open reading frame are expressed as GST fussion proteins both with a molecular mass of about 34 kDa. Conclusion:①TSA8 ku genes are first cloned;②TSA8KD-1, TSA8KD-2, TSA8KD-3, TSA8KD-4, TSA8KD-5, TSA8KD-11, TSA8KD-12 and TSA8KD-17 gene of TSA8 kDa family genes should be important and candidate immunodiagnositic antigen genes for bovine cysticercosis;③Comparison of relative sequences indicates that AgB1 and AgB2 has 97~100% similarity of nucleotides with responding AgB1 and AgB2 genes depodited in GeneBank;④The best expression induce conditions are 2×YT culture medium and 0.1 mmol/L IPTG at 37℃for 6h.