Perkinsea: what the hell are they doing in freshwater lake ecosystem
Résumé
Molecular ecology studies revealed a high diversity and the relative abundance of tiny eukaryotic parasites in marine waters as well as in freshwater lakes. In lake environments, these parasites belong mainly to the phyla of Fungi and Alveolates. Perkinsozoa constitute an example of non-yet cultivated putative parasites belonging to the Alveolates recently discovered in lake ecosystems. Recent studies showed the recurrent presence and the quantitative importance of Perkinsozoa zoospores in the epilimnion of lakes as well as their activity deduced by RNA/DNA analysis. However, we still have no idea about the potential hosts of theses parasites and their impact on the food web functioning. In order to gain more information on freshwater Perkinsea, we used (1) a meta- analysis of public Perkinsea 18S ribosomal RNA gene sequences available from the freshwater environments, (2) microscopic observations of Perkinsea associated with planktonic communities and (3) single amplified genome analysis and (4) metatranscriptomic data.