摘要:AbstractOocysts recovered fromMus musculuswere morphologically described and molecularly characterized using 18S rDNA and ITS1 regions. Sporulated oocysts had two layers and were sub-spherical measuring 20.76 (19.41–22.33) × 17.46 (15.44–19.15) μm with a length/width index of 1.18. Sporocysts were with stieda and substieda bodies with sporocystic residuum. Molecular data from both 18S rDNA and ITS1 regions revealed that the species under investigation is related toEimeria papillata. The 18S rDNA sequences obtained in this investigation were identical to anE. papillatasequence fromM. musculusfound in GenBank. The sequence obtained from the ITS-1 region showed a slight difference from other sequences fromE. papillatafor the same region with a similarity percent of 97.2% to 100%. The AT content of the ITS1 region from the present study was found to be 53.1%. According to ITS1 data, 10 haplotypes were characterized with haplotype diversity (Hd) of 0.9271. Sequences of the ITS1 region fromE. papillatawere variable in 18 sites with 3 indels, of those variable sites 15 were transitions while 3 were transversions. Therefore; the ITS1 region is probably a good marker for differentiating different strains ofEimeriaspecies in rodents.