Lactate dehydrogenase (LDH, E.C.1.1.1.27) was found in supernatant (cytoplasmic enzyme) fractions of the trypanosomatid flagellates Trypanosoma conorhini and Crithidia fasciculata if 10 mm cysteine was present in the homogenizing medium. The T. conorhini LDH activity with pyruvate as substrate was increased 35% if 5 mm cysteine was also included in reaction mixtures. K(m) values for the T. cono...

Crithidia fasciculata cells grown in defined medium are sensitive to methotrexate (MTX), an inhibitor of dihydrofolate reductase (DHFR). When cells are challenged with 2-5 microM MTX, cell division ceases after 3-4 divisions and the cells become rounded and immotile for approximately 60 h, with a 40% decrease in cell viability occurring during this period. The cells then recover normal morpholo...

Interestingly, there is a major difference in turnover rate between ornithine decarboxylases (ODCs) from various trypanosomatids. ODCs from Trypanosoma brucei and Leishmania donovani are both stable proteins, whereas ODC from Crithidia fasciculata is a metabolically unstable protein in the parasite. C. fasciculata ODC is also rapidly degraded in mammalian systems, whereas the closely related L....

Since 2006, honey bee colonies in North America and Europe have experienced increased annual mortality. These losses correlate with increased pathogen incidence and abundance, though no single etiologic agent has been identified. Crithidia mellificae is a unicellular eukaryotic honey bee parasite that has been associated with colony losses in the USA and Belgium. C. mellificae is a member of th...

AIMS The aims of this study were to design universal markers for different protozoan parasites of Bombus spp. based on the phylogenetic position of two important bumblebee parasites Crithidia bombi and Apicystis bombi. METHODS AND RESULTS Standard PCR and extraction techniques were used to amplify and sequence 18S rDNA. Phylogenetic analysis of the rDNA was performed in order to predict the p...

The life cycle of the trypanosomatid Crithidia fasciculata is monogenetic, as the unique hosts of these parasites are different species of culicids. The comparison of these non-pathogenic microorganisms evolutionary close to other species of trypanosomatids that develop digenetic life cycles and cause chronic severe sickness to millions of people worldwide is of outstanding interest. A ground-b...

beta-d-Glucosylhydroxymethyluracil, also called base J, is an unusual modified DNA base conserved among Kinetoplastida. Base J is found predominantly in repetitive DNA and correlates with epigenetic silencing of telomeric variant surface glycoprotein genes. We have previously found a J-binding protein (JBP) in Trypanosoma, Leishmania, and Crithidia. We have now characterized the binding propert...