|SCHWARZ, RYAN - University Of Maryland
|Murphy, Charles - Charlie
|RAVOET, JORGEN - Ghent University
|DE GRAAF, DIRK - Ghent University
Submitted to: Protist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/21/2014
Publication Date: 3/20/2015
Publication URL: http://DOI:10.1111/jeu.12209
Citation: Schwarz, R.S., Bauchan, G.R., Murphy, C.A., Ravoet, J., De Graaf, D.C., Evans, J.D. 2015. Genetic and ultrastructure characterization of a known and a new species of trypanosomatidae from the honey bee Apis mellifera: Crithidia mellificae Langridge and McGhee, 1967 and Leptomonas passim sp. n. Protist. 1:1-17.
Interpretive Summary: The causes of honey bee declines remain mysterious in many cases, due to the many potential causes of honey bee stress. Parasites are among the most common causes for bee declines. We have determined bee response to trypanosome gut parasites, and the effects of these parasites on bee health. We discovered that the identification of these parasites was incorrect and this paper describes a correction of taxonomy for this group, using morphology and genetics. Bee researchers and regulators can use this new information to assess and mitigate the effects of this parasite on bee health.
Technical Abstract: Trypanosomes are increasingly recognized as prevalent in European honey bee (Apis mellifera) colonies and by default are attributed to one formally recognized species, Crithidia mellificae Langridge and McGhee, 1967. We have undertaken a taxonomic evaluation of the two reference isolates of C. mellificae (ATCC 30254 and 30862) in comparison with two recent trypanosomatid isolates obtained from A. mellifera on the east (strain BRL) and west (strain SF) coast of the U.S.A. using cell ultrastructure analyses and genetic analyses of two nuclear DNA loci, glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH) and the small subunit of ribosomal RNA (SSU); and a kinetoplast DNA locus, cytochrome b (Cytb). Phylogenetic analyses of these loci support that strains BRL/SF form a novel taxonomic unit that is distinct from C. mellificae strains 30254/30862 and that both taxa arise within the subfamily Leishmaniinae. Confocal and electron microscopy images showC. mellificae is morphologically unique from the novel taxonomic unit represented by strains BRL/SF and we propose the binomial Leptomonas passim sp. n. for this previously undescribed species. We also analyze new and previously accessioned genetic data showing C. mellificae is still extant in bee populations, including both A. mellifera and Osmia bicornis(red mason bee), however L. passim sp. n. is likely the predominant trypanosome species present in current populations of A. mellifera across the globe. Our findings require that previous reports of C. mellificae be reconsidered and future reports carefully support species designations attributed to any trypanosomatid detected in bees and wasps.