The Canadian Institute for Advanced Research, Program in Integrated Microbial Biodiversity, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 1X5, Canada. jmarchib@dal.ca
Determination of the number of times that plastids have been gained and lost during eukaryotic evolution has proven difficult. A recent study has uncovered what could be the molecular signature of a photosynthetic ancestry for an important plastid-lacking lineage of microbial eukaryotes--the ciliates.