title: Increase of DNA content in tissue stages of Entamoeba histolytica strain SFL 3.
abstract: The DNA content of culture forms and tissue stages of pathogenic E. histolytica strain SFL 3 were measured photometrically after the nuclei had been stained with the fluorochrome BAO. As a control, the DNA guartity of E. histolytica strain HK 9 and E. invadens were determined by the same method and compared with reference values. Tissue stages were obtained from hamsters experimentally infected by intrahepatic injection of SFL 3 amoebae. Further studies concerning possible changes in the DNA content of tissue stages involved the following methods: (a) isolation of tissue stages from the liver, followed by distinct suspension periods. (b) Infected liver pieces were directly transferred into culture medium; amoebae emigrating therefrom were cultivated. The study demonstrated that tissue stages contained up to 4 times more DNA than did culture forms. After 3 h cultivation, the DNA content of tissue stages decreased to the level of culture forms. Possible reasons for this change are discussed.
authors.affiliation: Lehrstuhl für Spezielle Zoologie und Parasitologie, Ruhr-Universität Bochum, Federal Republic of Germany.
authors.forename: U
authors.initials: U
authors.lastname: Mackenstedt
authors.forename: M
authors.initials: M
authors.lastname: Schmidt
authors.forename: W
authors.initials: W
authors.lastname: Raether
authors.forename: H
authors.initials: H
authors.lastname: Mehlhorn
authors.forename: M
authors.initials: M
authors.lastname: Uphoff
mesh_terms: D000562:Amebiasis / Q000469:parasitology*; D000818:Animals; D006224:Cricetinae; D004247:DNA / Q000032:analysis*; D004748:Entamoeba histolytica / Q000235:genetics* / Q000472:pathogenicity; D004749:Entamoebiasis / Q000469:parasitology*; D006801:Humans; D008099:Liver / Q000469:parasitology; D008647:Mesocricetus
chemical_list: D004247:DNA