Localization of 3H-thymidine in oocyte Mitochondria from Schistosoma mansoni.
Cytoplasmic 3H-thymidine incorporated in oocytes of Schistosoma mansoni as seen on light microscope autoradiograms was removed by DNAase but not RNAase. On electron microscope autoradiograms, silver grains produced by 3H-thymidine were closely associated with mitochondria of oocytes. High resolution autoradiograms of 3H-actinomycin D, a compound which binds to nuclear and mitochondrial DNA, showed a majority of extranuclear silver grains was associated with mitochondria of oocytes. Exposure of worm sections to 4', 6-diamidino-2-phenylindole (DAPI), a compound that forms a fluorescent complex with DNA, produced a brilliant fluorescence in nuclei and cytoplasm of oocytes which was removed by DNAase but not RNAase. Incorporation of 3H-thymidine into nuclei and cytoplasmic components of oocytes was inhibited by two DNA-binding compounds, DAPI and acriflavin. This evidence indicted that the thymidine label emanated from mitochondrial DNA within the closely packed mitochondria of mature oocytes of S. mansoni.
D000167:Acriflavine / Q000494:pharmacology; D000578:Amidines / Q000494:pharmacology; D000818:Animals; D004272:DNA, Mitochondrial / Q000378:metabolism; D005260:Female; D007211:Indoles / Q000494:pharmacology; D008928:Mitochondria / Q000378:metabolism*; D009865:Oocytes / Q000378:metabolism* / Q000648:ultrastructure; D010063:Ovum / Q000378:metabolism*; D012550:Schistosoma mansoni / Q000378:metabolism*; D013936:Thymidine / Q000378:metabolism*
D000578:Amidines; D004272:DNA, Mitochondrial; D007211:Indoles; D000167:Acriflavine; C007293:DAPI; D013936:Thymidine