Submitted to: Journal of Eukaryotic Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/21/2003
Publication Date: 2/21/2004
Citation: Vossbrinck, C.R., Andreadis, T.G., Vavra, J., Becnel, J.J. 2004. Molecular phylogeny and evolution of mosquito parastic microsporidia (microsporidia: amblyosporidae). Journal of Eukaryotic Microbiology. 51(1):88-95. Interpretive Summary: Naturally occurring protozoan parasites (Microsporidia) of mosquitoes are under study to evaluate and develop these disease causing organisms as biological control agents. Microsporidian parasites are known to cause mortality in mosquitoes worldwide, but fundamental knowledge on the phylogenetic relationships of different mosquito microsporidia is unknown. This molecular investigation compares six species and four genera of microsporidia from mosquito hosts. The results indicate that the mosquito microsporidia form a related group which is contrary to current taxonomic schemes. Furthermore, the pattern of host relationships indicate that speciation of the parasite follows speciation of the mosquito host and is an important mechanism in the evolution of the microsporidia. The new information obtained here contributes to our basic understanding of these parasites which will assist in the evaluation and development of microsporidia as biocontrol agents.
Technical Abstract: Amblyospora and related species were isolated from mosquitoes, black flies and copepods and the small subunit ribosomal DNA gene was sequenced. The comparative phylogenetic analysis for this study shows co-evolution agreement between the mosquito host genera and Amblyospora parasite species with a Culex group of Amblyospora, and an Aedes/Ochlerotatus group. Parathelohania, which infect Anopheline mosquitoes, is perhaps, the sister group to the Amblyospora in the same way that the Anopheline mosquitoes are a sister group to the Culex and Aedes mosquitoes. In addition we demonstrate sequence identity in mosquito and copepod stages for 4 species of Amblyospora, bypassing the necessity of life cycle experiments. Several other points were observed in this study. Amblyospora species are specific for their primary (mosquito) host and each mosquito species serves as host for only one Amblyospora species. On the other hand a single species of copepod can act as a secondary host to several Amblyospora species and some Amblyospora species may use more than one copepod host. (Culicospora is not monotypic, Weiser and Prasertphon, 1982 described C. damnosi from a black fly) such as Edhazardia and Culicospora, which do not have an intermediate host but which have a lanceolate spore type which is ultrastructurally very similar to the Amblyospora spore type of the copepod, cluster within the Amblyospora species. Another species within a monotypic genus with Amblyospora -like characteristics, Intrapredatorus barri also falls well within the Amblyosproa clade. In the future, the genus Amblyospora may be redefined without the necessity for an intermediate host and future descriptions should try to include all spore types. Various other Microsporidia of aquatic organisms including Hazardia, Berwaldia and Gurleya also form an association which will have to be worked out upon analysis of additional aquatic genera. Three species (Janacekia, debaisieuxi, Amblyospora bracteata and Polydispryenia simulii) from the black fly Odagamia ornata also seem to have a loose phylogenetic association.