Bhattacharya S, Bhattacharya A, Diamond L S
Laboratory of Parasitic Diseases, National Institutes of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892.
Exp Parasitol. 1992 Mar;74(2):200-4. doi: 10.1016/0014-4894(92)90047-e.
The ribosomal RNA genes of the protozoan parasite Entamoeba histolytica are highly repeated and display restriction fragment length polymorphism. Using a set of four DNA probes spanning the coding region and part of the flanking region of the E. histolytica ribosomal RNA genes, an analysis of the DNA bands generated by EcoRI digestion of Entamoeba DNA is presented. This analysis included five strains of E. histolytica, four strains of E. moshkovskii, and one strain each of E. invadens and E. terrapinae. No common bands were observed between E. histolytica and the other Entamoeba. Within E. histolytica, two bands were conserved in all strains while the others were polymorphic. Detailed analysis of DNA from independently isolated clones of the strain HM-1:IMSS of E. histolytica showed two bands to be highly polymorphic. Of these, the 4.4-kb band of clone 6 was further analyzed. Polymorphism in this band could even be demonstrated in cells of the same clone. Restriction enzyme analysis of this DNA band from two clones of HM-1:IMSS showed that the polymorphism may be due to variable numbers of DraI repeat units present in this DNA stretch.
原生动物寄生虫溶组织内阿米巴的核糖体RNA基因高度重复，并表现出限制性片段长度多态性。使用一组跨越溶组织内阿米巴核糖体RNA基因编码区和部分侧翼区的四种DNA探针，对溶组织内阿米巴DNA经EcoRI酶切产生的DNA条带进行了分析。该分析包括五株溶组织内阿米巴、四株莫斯科维茨内阿米巴以及一株侵袭内阿米巴和一株龟内阿米巴。在溶组织内阿米巴与其他内阿米巴之间未观察到共同条带。在溶组织内阿米巴内部，所有菌株中有两条带是保守的，而其他带则是多态性的。对溶组织内阿米巴菌株HM-1:IMSS独立分离克隆的DNA进行的详细分析表明，有两条带具有高度多态性。其中，对克隆6的4.4-kb条带进行了进一步分析。同一克隆的细胞中甚至也能显示出该条带的多态性。对来自HM-1:IMSS两个克隆的该DNA条带进行的限制性酶切分析表明，多态性可能是由于该DNA片段中存在数量可变的DraI重复单元。
