Aquatic Molecular Microbial Biology

Our molecular characterizations of poorly known aquatic protists have provided new insight into early eukaryotic diversifications relevant to the origin of the streptophytes. For example, Eunsoo Kim’s analyses of eukaryotic elongation factor 2 gene sequences strongly support a clade that includes red and green algae and land plants, but also haptophytes and cryptophytes and close plastidless relatives (see below). This newly-recognized clade, which we have named Plastidophila (because most members possess plastids), suggests the nature of the plastidless ancestors of the modern plant lineage and that both primary & secondary endosymbiosis occurred more than once in the history of algal plastids.