Probing protistan phylogenies with an anti-tubulin antibody

Representatives from most of the protist phyla were probed by immunofluorescence or by immunoblotting with an anti-tubulin antibody of sharp specificity previously raised against Paramecium axonemal tubulin. Excellent intra-phylum homogeneity of results was recorded except for chlorophytes. All ciliates, dinoflagellates and cryptomonads tested were strongly positive while actinopods, Euglenozoa and parabasalids were negative. All representatives of the broad chromophyte assemblage were positive while all rhizopods were negative. This simple binary immunological character was superimposed on a number of published protist phylogenies and seen to fit very well with some of them. Other immunological approaches to protist taxonomy and evolution are briefly reviewed.