ABSTRACT
We report a study on the DNA organization in Entamoeba histolytica using a ribosomal DNA probe. The rDNA genes were found forming mers which were separated in a typical ladder pattern by pulse field electrophoresis. DNA rosette structures were visualized through electron microscopy in DNA eluted from bands recognized by the ribosomal probe. The in situ hybridization experiments using a DNA probe suggested that the rDNA genes are portioned between the nucleus and a cytoplasmic structure. These findings provide new data on DNA organization in E. histolytica and open the question concerning the presence of a novel organelle in this eukaryotic parasite
Subject(s)
Animals , DNA, Ribosomal/genetics , DNA, Ribosomal/ultrastructure , Cytoplasm/chemistry , DNA, Protozoan/genetics , DNA, Protozoan/ultrastructure , Entamoeba histolytica/genetics , Entamoeba histolytica/ultrastructure , In Situ HybridizationABSTRACT
Observamos a cromatina de formas amstigotad de T. cruzi associada a cromossomos de macrófagos metafásicos obtidos em diversos períodos da infecçäo aguda. O estudo imunocitogenético demonstrou que o material genético inserido naqueles cromossomos era produto do T. cruzi. Pelo teste de hibridaza ao in situ com sonda biotinilada de DNA de T. cruzi, foi confirmada a inserçäo de DNA do protozoário nos cromossomos murinos. A inserçäo seletiva de 3H-DNA do protozoário em alguns cromossomos sugere que podem ocorrer rearranjos transxenogênicos em infecçöes de mamiferos pelo T. cruzi