A genetic toolbox for marine protists

Microbial life is most often associated with prokaryotes (Bacteria and Archaea). However, enormous biological diversity lies in protists, or eukaryotic microbes. For much of the history of biological investigation, protists have been the focus of far less intense research than complex multicellular eukaryotes. However, over the last twenty years the molecular biological revolution has brought the importance of protists to light. Faktorová et al.1 now provide a set of tools for the genetic manipulation of diverse protists, which will enable many new types of studies. Ecologically, protists are now known to be key players in the environment. They occupy nearly all ecological niches, they may be autotrophic or heterotrophic, and they are major drivers in global biogeochemical processes2. They are the predominating biomass in the world’s oceans as well as major contributors to biomass in terrestrial environments3. Recent efforts to holistically catalog the planktonic biodiversity of the world’s oceans through environmental sequencing have revealed the sheer number of microbial eukaryotic taxa present in marine environments, highlighting their critical biological contribution. Even microbial protist lineages historically perceived to be species poor and rare in the environment are now known to be highly diverse and are major components of marine ecosystems4. Perhaps the greatest shift in biological thinking regarding protists has come about through the use of molecular sequence data to reconstruct the eukaryotic tree of life5–7. Historically, protists were placed into a grab bag of life, perceived as a separate entity: Protista. The classical eukaryotic kingdom-level lineages (Animalia, Fungi and Plantae) are now known to be sublineages within suprakingdoms wherein most if not all other lineages are protists. This model of eukaryotic relationships is referred to as the supergroup model6. Thus, it is from protistan relatives that complex multicellular groups like animals, plants and fungi evolved.

 

Brown M.W., Tice A.K. 2020: A genetic toolbox for marine protists. Nature Methods (in press).