The Sequence and Phylogenetic Analysis of 18S rDNA of E.intestinalis

Using single-oocyst seperation technology,E.intestinalis was isolated from rabbit in Hebei,then inoculated coccidia-free rabbits to propagate.Its genomic DNA was extracted by the method of CATB.Using conservative primer of 18S rDNA of Eimeria,18S rDNA gene fragment of E.intestinalis HB was amplified and sequenced.Among E.intestinalis HB and 11 species of rabbit-infecting Eimeria in the GenBank,the phylogenetic tree was constructed based on their 18S rDNA sequences by DNAstar software.The amplification results indicated that the gene fragment was amplified with 1 521 bp.The analysis of the percent identity showed that E.intestinalis HB shared the homology of 92.6%-99.9% with 18S rDNA sequence of 11 species of rabbit infecting Eimeria.The homology between E.intestinalis HB and E.intestinalis(EF694012) is 99.9%.The tree of phylogenetic analysis show that E.intestinalis HB and E.intestinalis(EF694012) are the most close.