Analysis Of Complete Small Subunit Ribosomal DNA Of Emeria Species From Chickens

Coccidiosis caused by protozoan parasites of the genus Emeria is an enteric disease of major economic world-wide importance, especially in China. 18S rDNA of 18 strains of 4 Eimeria species were PCR amplified, cloned and sequenced for phylogenetic relationships among 15 Eimeria species/strains and difference between the anti-drug strains and drug-sensitive strain.1. phylogenetic relationships among the Emeria speciesFor phylogenetic analysis of the Emeria species from chickens in some areas of China, 18S rDNA of the sporulated oocysts of 1 strain of E.necatrix, 5 strains of E. maxima, 2 strains of E.acervulina, and 7 strains of E.tenella were amplified by PCR. The products of PCR were cloned into pGEM-T easy vector and sequenced. Blast program examination showed that the cloned DNA fragments which were about 1800 bp in length were the 18S rDNAs of above mentioned Emeria species/strains. DNAstar 5.0 MegAlign soft analysis revealed that the homologies of the 18S rDNAs of the 4 Emeria spaces was 94.6%~99.4%, the homologies of the 18S rDNAs of the 7 strains of E.tenella was 99.0%~99.9%, and the homologies of the 18S rDNAs of the 5 strains of E.maxima was 96.9%~99.8%. The phylogenetic tree with the 8 Emeria spaces (4 speces downloaded from GenBank) formed two clades, one was composed of EASH, EMSH, E.mivati, E.mitis, E.brunetti and E.praecox, the other was composed ENSH and ETAS. The phylogenetic was different from that reported previous. Each of the the phylogenetic tree with the 7 strains of E.tenella and with the 5 strains of E.maxima has two clades which based on the different area.This research should be basis on which the ultimate and definitive means is established for origin identification of the Eimeria species from chickens in china.2. difference between the E.tenella drug-resistance strains ans the drug-sensitive strainTo analyze the effect of the drug diclazuril and maduramycin on the 18S rDNA of E.tenella , the 18S rDNA of sporutated oocysts of the E.tenella anti-diclazuri strain...