[Cloning and sequencing of the gp23 gene encoding a surface antigen on sporozoites of Cryptosporidium parvum].

Objective: To clone and sequence the gp23 gene encoding a surface antigen on the sporozoites of Cryptosporidium parvum.

Methods: Genomic DNA was isolated from oocysts of Cryptosporidium parvum. The gp23 gene was amplified by polymerase chain reaction (PCR) and cloned into pMD18-T vector and sequenced by the methods of dideoxy-mediated chain termination.

Results And Conclusion: The gp23 gene was 345 bp in length and included an open reading frame encoding a protein of 114 amino acid residues. The homology of the nucleotide and amino sequences of the gp23 gene was 97.3% and 98.2% to that in the GenBank, respectively. The gp23 gene cloned contained 6 nucleotides more than that in the GenBank.