Increase of DNA content in tissue stages of Entamoeba histolytica strain SFL 3.
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.
Mackenstedt
U
U
Lehrstuhl für Spezielle Zoologie und Parasitologie, Ruhr-Universität Bochum, Federal Republic of Germany.
Schmidt
M
M
Raether
W
W
Mehlhorn
H
H
Uphoff
M
M
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
D004247:DNA