Base J originally found in kinetoplastida is also a minor constituent of nuclear DNA of Euglena gracilis

We have analyzed DNA of Euglena gracilis for the presence of the unusual minor base beta-D-glucosylhydroxymethyluracil or J, thus far only found in kinetoplastid flagellates and in Diplonema, Using antibodies specific for J and post-labeling of DNA digests followed by two-dimensional thin-layer chromatography of labeled nucleotides, we show that similar to 0.2 mole percent of Euglena DNA consists of J, an amount similar to that found in DNA of Trypanosoma brucei, By staining permeabilized Euglena cells with anti-J antibodies, we show that J is rather uniformly distributed in the Euglena nucleus, and does not co-localize to a substantial extent with (GGGTTA)(n) repeats, the putative telomeric repeats of Euglena, Hence, most of J in Euglena appears to be non-telomeric, Our results add to the existing evidence for a close phylogenetic relation between kinetoplastids and euglenids.