Université de Fribourg

The impact of infection on host competition and its relationship to parasite persistence in a Daphnia microparasite system

Refardt, Dominik ; Ebert, Dieter

In: Evolutionary Ecology, 2012, vol. 26, no. 1, p. 95-107

Evolutionary studies often estimate fitness components with the aim to make predictions about the outcome of selection. Depending on the system and the question, different fitness components are used, but their usefulness for predicting the outcome of selection is rarely tested. Here we estimate host fitness components in different ways with the aim to test how well they agree with each other...

Université de Fribourg

Morphology, molecular phylogeny, and ecology of Binucleata daphniae n. g., n. sp. (Fungi: Microsporidia), a parasite of Daphnia magna Straus, 1820 (Crustacea: Branchiopoda)

Refardt, Dominik ; Decaestecker, Ellen ; Johnson, Pieter T. J. ; Vávra, Jirí

In: Journal of Eukaryotic Microbiology, 2008, vol. 55, no. 5, p. 393 - 408

We describe a new microsporidian species Binucleata daphniae, n. g., n. sp., that infects the integument cells lining the hemocoele cavity of the carapace and the postabdomen of the cladoceran Daphnia magna Straus. Infected cells filled with spores accumulate as large clusters in the carapace cavity and heavily infected hosts are detected by their opaque appearance. Despite the parasite's...

Université de Fribourg

Quantitative PCR to detect, discriminate and quantify intracellular parasites in their host: an example from three microsporidians in Daphnia

Refardt, Dominik ; Ebert, Dieter

In: Parasitology, 2006, vol. 133, p. 11–18

Reliable detection, discrimination and quantification of parasites are important for host-parasite studies and diagnostics. Microsporidial infections are problematic in this respect. Their discrimination and quantification using light microscopy is difficult because spores are the only light microscopically visible form of the parasite and they offer few distinct characters. We developed a...

Université de Fribourg

Variation in phenoloxidase activity and its relation to parasite resistance within and between populations of Daphnia magna

Mucklow, Patrick T. ; Vizoso, Dita B. ; Jensen, Knut Helge ; Refardt, Dominik ; Ebert, Dieter

In: Proceedings of the Royal Society of London: Biological Sciences, 2004, vol. 271, p. 1175-1183

Estimates of phenoloxidase (PO) activity have been suggested as a useful indicator of immunocompetence in arthropods, with the idea that high PO activity would indicate high immunocompetence against parasites and pathogens. Here, we test for variation in PO activity among clones of the planktonic crustacean Daphnia magna and its covariation with susceptibility to infections from four different...