Bumblebees, amongst the most important of pollinators, are under enormous population pressures. One of these is disease. The bumblebee and its gut trypanosome Crithidia bombi are one of the fundamental models of ecological immunology. Although there is previous evidence of increased immune gene expression upon Crithidia infection, recent work has focussed on the bumblebee's gut microbiota. Here...

Norepinephrine was isolated from the flagellated protozoan, Crithidia jasciculata, and the ciliated protozoan, Tetrahymena pyrijormis, the former having less than onehalf that of the latter. Tetrohymena also synthesizes epinephrine, whereas this substance could not be detected in Crithidia. Isotopically labeled phenylalanine, tyrosine, and dihydroxyphenylalanine were significantly incorporated ...

The synthesis of secondary metabolites is a hallmark of plant defence against herbivores. These compounds may be detrimental to consumers, but can also protect herbivores against parasites. Floral nectar commonly contains secondary metabolites, but little is known about the impacts of nectar chemistry on pollinators, including bees. We hypothesized that nectar secondary metabolites could reduce...

Crithidia fasciculata cells were treated with a plasmid (pDK96) containing pBR322 sequences, a Leishmania tarentolae maxicircle autonomously replicating sequence, and the bacterial gene for aminoglycoside 3' phosphotransferase I inserted between the yeast alcohol dehydrogenase 1 promotor and terminator sequences. Resistant colonies were selected on agar plates containing paromomycin and screene...

SYNOPSIS. Attempts at continuous labeling of Crithidia fasciculata D.N.A with ["H]thymidine led to a pulse-chase situation due to a ccll-mediated conversion of thymidine to thymine in the medium. The uptake of ihymine was slow compared to that of thymidine. Neither the addition of deoxyadenosine nor the sequential addition of several aliquots of ['H] thymidine had an effect on the pattern of la...

Antinuclear antibodies are almost always found in sera of patients with systemic lupus erythematosus. To differentiate antinuclear antibodies from antibodies to DNA in the recently described Crithidia luciliae assay, we developed an immunoperoxidase technique for detecting antibodies to native, double-stranded DNA and compared results by it with those by the Farr assay. Smears of cultured Crith...

Floral nectar contains secondary compounds with antimicrobial properties that can affect not only plant-pollinator interactions, but also interactions between pollinators and their parasites. Although recent work has shown that consumption of plant secondary compounds can reduce pollinator parasite loads, little is known about the effects of dosage or compound combinations. We used the generali...

DNA minicircles found within the kinetoplast of the trypanosomatid Crithidia fasciculata, like those of most other kinetoplastid species, are heterogeneous in sequence. The pattern of minicircle DNA fragments generated by cleavage of kinetoplast DNA with various restriction enzymes has been used to demonstrate this heterogeneity. Here we describe a strain of Crithidia fasciculata in which more ...

The genotypic structure of parasite populations is an important determinant of ecological and evolutionary dynamics of host-parasite interactions with consequences for pest management and disease control. Genotypic structure is especially interesting where multiple hosts co-exist and share parasites. We here analyze the natural genotypic distribution of Crithidia bombi, a trypanosomatid parasit...