Phylogenetic Analysis of Five Rabbit Eimeria Species Based on the ITS-1 Sequence

This experiment was conducted to study the correlation of morphological and biological features to the phylogeny of rabbit coccidia.Five species of rabbit coccidia were isolated by single-oocyst separation technology and proliferated.Genomic DNA was extracted from their sporulated oocysts by the method of CATB.The ITS-1 regions were cloned and sequenced,then they were aligned with corresponding sequence in the GenBank.The phylogenetic tree was obtained by NJ method.The complete ITS-1 sequences of E.magna HB,E.flavescens HB,E.intestinalis HB,E.media HB,E.perforans HB were 320,330,351,336 and 341 bp respectively in length.The sequence identities displayed 96.9%,97.3%,96.9%,99.1% and 99.4%.Based on the ITS-1sequence data,the rabbit coccidia monophyly was divided into 2 sister lineages,which was corresponding to the presence/absence of the oocyst residuum.Other morphological or biological traits(oocyst shape and size,pathogenicity,infection site,pre-patent and patent periods,and number of asexual generations) do not explicitly correlate with the phylogeny of rabbit coccidia.The presence/absence of oocyst residuum is an evolutionarily conserved feature.